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Mizrahi 3 Internet-Draft HUAWEI 4 Intended status: Informational E. Grossman, Ed. 5 Expires: April 19, 2019 DOLBY 6 A. Hacker 7 MISTIQ 8 S. Das 9 Applied Communication Sciences 10 J. Dowdell 11 Airbus Defence and Space 12 H. Austad 13 Cisco Systems 14 K. Stanton 15 INTEL 16 N. Finn 17 HUAWEI 18 October 16, 2018 20 Deterministic Networking (DetNet) Security Considerations 21 draft-ietf-detnet-security-03 23 Abstract 25 A deterministic network is one that can carry data flows for real- 26 time applications with extremely low data loss rates and bounded 27 latency. Deterministic networks have been successfully deployed in 28 real-time operational technology (OT) applications for some years 29 (for example [ARINC664P7]). However, such networks are typically 30 isolated from external access, and thus the security threat from 31 external attackers is low. IETF Deterministic Networking (DetNet) 32 specifies a set of technologies that enable creation of deterministic 33 networks on IP-based networks of potentially wide area (on the scale 34 of a corporate network) potentially bringing the OT network into 35 contact with Information Technology (IT) traffic and security threats 36 that lie outside of a tightly controlled and bounded area (such as 37 the internals of an aircraft). These DetNet technologies have not 38 previously been deployed together on a wide area IP-based network, 39 and thus can present security considerations that may be new to IP- 40 based wide area network designers. This draft, intended for use by 41 DetNet network designers, provides insight into these security 42 considerations. In addition, this draft collects all security- 43 related statements from the various DetNet drafts (Architecture, Use 44 Cases, etc) into a single location Section 7. 46 Status of This Memo 48 This Internet-Draft is submitted in full conformance with the 49 provisions of BCP 78 and BCP 79. 51 Internet-Drafts are working documents of the Internet Engineering 52 Task Force (IETF). Note that other groups may also distribute 53 working documents as Internet-Drafts. The list of current Internet- 54 Drafts is at https://datatracker.ietf.org/drafts/current/. 56 Internet-Drafts are draft documents valid for a maximum of six months 57 and may be updated, replaced, or obsoleted by other documents at any 58 time. It is inappropriate to use Internet-Drafts as reference 59 material or to cite them other than as "work in progress." 61 This Internet-Draft will expire on April 19, 2019. 63 Copyright Notice 65 Copyright (c) 2018 IETF Trust and the persons identified as the 66 document authors. All rights reserved. 68 This document is subject to BCP 78 and the IETF Trust's Legal 69 Provisions Relating to IETF Documents 70 (https://trustee.ietf.org/license-info) in effect on the date of 71 publication of this document. Please review these documents 72 carefully, as they describe your rights and restrictions with respect 73 to this document. Code Components extracted from this document must 74 include Simplified BSD License text as described in Section 4.e of 75 the Trust Legal Provisions and are provided without warranty as 76 described in the Simplified BSD License. 78 Table of Contents 80 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 81 2. Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . 5 82 3. Security Threats . . . . . . . . . . . . . . . . . . . . . . 6 83 3.1. Threat Model . . . . . . . . . . . . . . . . . . . . . . 6 84 3.2. Threat Analysis . . . . . . . . . . . . . . . . . . . . . 7 85 3.2.1. Delay . . . . . . . . . . . . . . . . . . . . . . . . 7 86 3.2.1.1. Delay Attack . . . . . . . . . . . . . . . . . . 7 87 3.2.2. DetNet Flow Modification or Spoofing . . . . . . . . 7 88 3.2.3. Resource Segmentation or Slicing . . . . . . . . . . 7 89 3.2.3.1. Inter-segment Attack . . . . . . . . . . . . . . 7 90 3.2.4. Packet Replication and Elimination . . . . . . . . . 8 91 3.2.4.1. Replication: Increased Attack Surface . . . . . . 8 92 3.2.4.2. Replication-related Header Manipulation . . . . . 8 93 3.2.5. Path Choice . . . . . . . . . . . . . . . . . . . . . 8 94 3.2.5.1. Path Manipulation . . . . . . . . . . . . . . . . 8 95 3.2.5.2. Path Choice: Increased Attack Surface . . . . . . 9 96 3.2.6. Control Plane . . . . . . . . . . . . . . . . . . . . 9 97 3.2.6.1. Control or Signaling Packet Modification . . . . 9 98 3.2.6.2. Control or Signaling Packet Injection . . . . . . 9 99 3.2.7. Scheduling or Shaping . . . . . . . . . . . . . . . . 9 100 3.2.7.1. Reconnaissance . . . . . . . . . . . . . . . . . 9 101 3.2.8. Time Synchronization Mechanisms . . . . . . . . . . . 9 102 3.3. Threat Summary . . . . . . . . . . . . . . . . . . . . . 9 103 4. Security Threat Impacts . . . . . . . . . . . . . . . . . . . 10 104 4.1. Delay-Attacks . . . . . . . . . . . . . . . . . . . . . . 13 105 4.1.1. Data Plane Delay Attacks . . . . . . . . . . . . . . 13 106 4.1.2. Control Plane Delay Attacks . . . . . . . . . . . . . 13 107 4.2. Flow Modification and Spoofing . . . . . . . . . . . . . 14 108 4.2.1. Flow Modification . . . . . . . . . . . . . . . . . . 14 109 4.2.2. Spoofing . . . . . . . . . . . . . . . . . . . . . . 14 110 4.2.2.1. Dataplane Spoofing . . . . . . . . . . . . . . . 14 111 4.2.2.2. Control Plane Spoofing . . . . . . . . . . . . . 14 112 4.3. Segmentation attacks (injection) . . . . . . . . . . . . 15 113 4.3.1. Data Plane Segmentation . . . . . . . . . . . . . . . 15 114 4.3.2. Control Plane segmentation . . . . . . . . . . . . . 15 115 4.4. Replication and Elimination . . . . . . . . . . . . . . . 15 116 4.4.1. Increased Attack Surface . . . . . . . . . . . . . . 15 117 4.4.2. Header Manipulation at Elimination Bridges . . . . . 15 118 4.5. Control or Signaling Packet Modification . . . . . . . . 16 119 4.6. Control or Signaling Packet Injection . . . . . . . . . . 16 120 4.7. Reconnaissance . . . . . . . . . . . . . . . . . . . . . 16 121 4.8. Attacks on Time Sync Mechanisms . . . . . . . . . . . . . 16 122 4.9. Attacks on Path Choice . . . . . . . . . . . . . . . . . 16 123 5. Security Threat Mitigation . . . . . . . . . . . . . . . . . 16 124 5.1. Path Redundancy . . . . . . . . . . . . . . . . . . . . . 16 125 5.2. Integrity Protection . . . . . . . . . . . . . . . . . . 17 126 5.3. DetNet Node Authentication . . . . . . . . . . . . . . . 17 127 5.4. Encryption . . . . . . . . . . . . . . . . . . . . . . . 17 128 5.5. Control and Signaling Message Protection . . . . . . . . 18 129 5.6. Dynamic Performance Analytics . . . . . . . . . . . . . . 18 130 5.7. Mitigation Summary . . . . . . . . . . . . . . . . . . . 18 131 6. Association of Attacks to Use Cases . . . . . . . . . . . . . 20 132 6.1. Use Cases by Common Themes . . . . . . . . . . . . . . . 20 133 6.1.1. Network Layer - AVB/TSN Ethernet . . . . . . . . . . 20 134 6.1.2. Central Administration . . . . . . . . . . . . . . . 21 135 6.1.3. Hot Swap . . . . . . . . . . . . . . . . . . . . . . 21 136 6.1.4. Data Flow Information Models . . . . . . . . . . . . 22 137 6.1.5. L2 and L3 Integration . . . . . . . . . . . . . . . . 22 138 6.1.6. End-to-End Delivery . . . . . . . . . . . . . . . . . 22 139 6.1.7. Proprietary Deterministic Ethernet Networks . . . . . 23 140 6.1.8. Replacement for Proprietary Fieldbuses . . . . . . . 23 141 6.1.9. Deterministic vs Best-Effort Traffic . . . . . . . . 23 142 6.1.10. Deterministic Flows . . . . . . . . . . . . . . . . . 24 143 6.1.11. Unused Reserved Bandwidth . . . . . . . . . . . . . . 24 144 6.1.12. Interoperability . . . . . . . . . . . . . . . . . . 24 145 6.1.13. Cost Reductions . . . . . . . . . . . . . . . . . . . 25 146 6.1.14. Insufficiently Secure Devices . . . . . . . . . . . . 25 147 6.1.15. DetNet Network Size . . . . . . . . . . . . . . . . . 25 148 6.1.16. Multiple Hops . . . . . . . . . . . . . . . . . . . . 26 149 6.1.17. Level of Service . . . . . . . . . . . . . . . . . . 26 150 6.1.18. Bounded Latency . . . . . . . . . . . . . . . . . . . 27 151 6.1.19. Low Latency . . . . . . . . . . . . . . . . . . . . . 27 152 6.1.20. Bounded Jitter (Latency Variation) . . . . . . . . . 27 153 6.1.21. Symmetrical Path Delays . . . . . . . . . . . . . . . 27 154 6.1.22. Reliability and Availability . . . . . . . . . . . . 28 155 6.1.23. Redundant Paths . . . . . . . . . . . . . . . . . . . 28 156 6.1.24. Security Measures . . . . . . . . . . . . . . . . . . 28 157 6.2. Attack Types by Use Case Common Theme . . . . . . . . . . 28 158 6.3. Security Considerations for OAM Traffic . . . . . . . . . 31 159 7. Appendix A: DetNet Draft Security-Related Statements . . . . 31 160 7.1. Architecture (draft 8) . . . . . . . . . . . . . . . . . 31 161 7.1.1. Fault Mitigation (sec 4.5) . . . . . . . . . . . . . 31 162 7.1.2. Security Considerations (sec 7) . . . . . . . . . . . 32 163 7.2. Data Plane Alternatives (draft 4) . . . . . . . . . . . . 32 164 7.2.1. Security Considerations (sec 7) . . . . . . . . . . . 32 165 7.3. Problem Statement (draft 5) . . . . . . . . . . . . . . . 33 166 7.3.1. Security Considerations (sec 5) . . . . . . . . . . . 33 167 7.4. Use Cases (draft 11) . . . . . . . . . . . . . . . . . . 33 168 7.4.1. (Utility Networks) Security Current Practices and 169 Limitations (sec 3.2.1) . . . . . . . . . . . . . . . 33 170 7.4.2. (Utility Networks) Security Trends in Utility 171 Networks (sec 3.3.3) . . . . . . . . . . . . . . . . 35 172 7.4.3. (BAS) Security Considerations (sec 4.2.4) . . . . . . 36 173 7.4.4. (6TiSCH) Security Considerations (sec 5.3.3) . . . . 37 174 7.4.5. (Cellular radio) Security Considerations (sec 6.1.5) 37 175 7.4.6. (Industrial M2M) Communication Today (sec 7.2) . . . 37 176 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 37 177 9. Security Considerations . . . . . . . . . . . . . . . . . . . 38 178 10. Informative References . . . . . . . . . . . . . . . . . . . 38 179 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39 181 1. Introduction 183 Security is of particularly high importance in DetNet networks 184 because many of the use cases which are enabled by DetNet 185 [I-D.ietf-detnet-use-cases] include control of physical devices 186 (power grid components, industrial controls, building controls) which 187 can have high operational costs for failure, and present potentially 188 attractive targets for cyber-attackers. 190 This situation is even more acute given that one of the goals of 191 DetNet is to provide a "converged network", i.e. one that includes 192 both IT traffic and OT traffic, thus exposing potentially sensitive 193 OT devices to attack in ways that were not previously common (usually 194 because they were under a separate control system or otherwise 195 isolated from the IT network). Security considerations for OT 196 networks is not a new area, and there are many OT networks today that 197 are connected to wide area networks or the Internet; this draft 198 focuses on the issues that are specific to the DetNet technologies 199 and use cases. 201 The DetNet technologies include ways to: 203 o Reserve data plane resources for DetNet flows in some or all of 204 the intermediate nodes (e.g. bridges or routers) along the path of 205 the flow 207 o Provide explicit routes for DetNet flows that do not rapidly 208 change with the network topology 210 o Distribute data from DetNet flow packets over time and/or space to 211 ensure delivery of each packet's data' in spite of the loss of a 212 path 214 This draft includes sections on threat modeling and analysis, threat 215 impact and mitigation, and the association of attacks with use cases 216 based on the Use Case Common Themes section of the DetNet Use Cases 217 draft [I-D.ietf-detnet-use-cases]. 219 This draft also provides context for the DetNet security 220 considerations by collecting into one place Section 7 the various 221 remarks about security from the various DetNet drafts (Use Cases, 222 Architecture, etc). This text is duplicated here primarily because 223 the DetNet working group has elected not to produce a Requirements 224 draft and thus collectively these statements are as close as we have 225 to "DetNet Security Requirements". 227 2. Abbreviations 229 IT Information technology (the application of computers to 230 store, study, retrieve, transmit, and manipulate data or information, 231 often in the context of a business or other enterprise - Wikipedia). 233 OT Operational Technology (the hardware and software 234 dedicated to detecting or causing changes in physical processes 235 through direct monitoring and/or control of physical devices such as 236 valves, pumps, etc. - Wikipedia) 237 MITM Man in the Middle 239 SN Sequence Number 241 STRIDE Addresses risk and severity associated with threat 242 categories: Spoofing identity, Tampering with data, Repudiation, 243 Information disclosure, Denial of service, Elevation of privilege. 245 DREAD Compares and prioritizes risk represented by these threat 246 categories: Damage potential, Reproducibility, Exploitability, how 247 many Affected users, Discoverability. 249 PTP Precision Time Protocol [IEEE1588] 251 3. Security Threats 253 This section presents a threat model, and analyzes the possible 254 threats in a DetNet-enabled network. 256 We distinguish control plane threats from data plane threats. The 257 attack surface may be the same, but the types of attacks as well as 258 the motivation behind them, are different. For example, a delay 259 attack is more relevant to data plane than to control plane. There 260 is also a difference in terms of security solutions: the way you 261 secure the data plane is often different than the way you secure the 262 control plane. 264 3.1. Threat Model 266 The threat model used in this memo is based on the threat model of 267 Section 3.1 of [RFC7384]. This model classifies attackers based on 268 two criteria: 270 o Internal vs. external: internal attackers either have access to a 271 trusted segment of the network or possess the encryption or 272 authentication keys. External attackers, on the other hand, do 273 not have the keys and have access only to the encrypted or 274 authenticated traffic. 276 o Man in the Middle (MITM) vs. packet injector: MITM attackers are 277 located in a position that allows interception and modification of 278 in-flight protocol packets, whereas a traffic injector can only 279 attack by generating protocol packets. 281 Care has also been taken to adhere to Section 5 of [RFC3552], both 282 with respect to what attacks are considered out-of-scope for this 283 document, but also what is considered to be the most common threats 284 (explored furhter in Section 3.2. Most of the direct threats to 285 DetNet are Active attacks, but it is highly suggested that DetNet 286 application developers take appropriate measures to protect the 287 content of the streams from passive attacks. 289 DetNet-Service, one of the service scenarios described in 290 [I-D.varga-detnet-service-model], is the case where a service 291 connects DetNet networking islands, i.e. two or more otherwise 292 independent DetNet network domains are connected via a link that is 293 not intrinsically part of either network. This implies that there 294 could be DetNet traffic flowing over a non-DetNet link, which may 295 provide an attacker with an advantageous opportunity to tamper with 296 DetNet traffic. The security properties of non-DetNet links are 297 outside of the scope of DetNet Security, but it should be noted that 298 use of non-DetNet services to interconnect DetNet networks merits 299 security analysis to ensure the integrity of the DetNet networks 300 involved. 302 3.2. Threat Analysis 304 3.2.1. Delay 306 3.2.1.1. Delay Attack 308 An attacker can maliciously delay DetNet data flow traffic. By 309 delaying the traffic, the attacker can compromise the service of 310 applications that are sensitive to high delays or to high delay 311 variation. 313 3.2.2. DetNet Flow Modification or Spoofing 315 An attacker can modify some header fields of en route packets in a 316 way that causes the DetNet flow identification mechanisms to 317 misclassify the flow. Alternatively, the attacker can inject traffic 318 that is tailored to appear as if it belongs to a legitimate DetNet 319 flow. The potential consequence is that the DetNet flow resource 320 allocation cannot guarantee the performance that is expected when the 321 flow identification works correctly. 323 3.2.3. Resource Segmentation or Slicing 325 3.2.3.1. Inter-segment Attack 327 An attacker can inject traffic, consuming network device resources, 328 thereby affecting DetNet flows. This can be performed using non- 329 DetNet traffic that affects DetNet traffic, or by using DetNet 330 traffic from one DetNet flow that affects traffic from different 331 DetNet flows. 333 3.2.4. Packet Replication and Elimination 335 3.2.4.1. Replication: Increased Attack Surface 337 Redundancy is intended to increase the robustness and survivability 338 of DetNet flows, and replication over multiple paths can potentially 339 mitigate an attack that is limited to a single path. However, the 340 fact that packets are replicated over multiple paths increases the 341 attack surface of the network, i.e., there are more points in the 342 network that may be subject to attacks. 344 3.2.4.2. Replication-related Header Manipulation 346 An attacker can manipulate the replication-related header fields 347 (R-TAG). This capability opens the door for various types of 348 attacks. For example: 350 o Forward both replicas - malicious change of a packet SN (Sequence 351 Number) can cause both replicas of the packet to be forwarded. 352 Note that this attack has a similar outcome to a replay attack. 354 o Eliminate both replicas - SN manipulation can be used to cause 355 both replicas to be eliminated. In this case an attacker that has 356 access to a single path can cause packets from other paths to be 357 dropped, thus compromising some of the advantage of path 358 redundancy. 360 o Flow hijacking - an attacker can hijack a DetNet flow with access 361 to a single path by systematically replacing the SNs on the given 362 path with higher SN values. For example, an attacker can replace 363 every SN value S with a higher value S+C, where C is a constant 364 integer. Thus, the attacker creates a false illusion that the 365 attacked path has the lowest delay, causing all packets from other 366 paths to be eliminated. Once the flow is hijacked the attacker 367 can either replace en route packets with malicious packets, or 368 simply injecting errors, causing the packets to be dropped at 369 their destination. 371 3.2.5. Path Choice 373 3.2.5.1. Path Manipulation 375 An attacker can maliciously change, add, or remove a path, thereby 376 affecting the corresponding DetNet flows that use the path. 378 3.2.5.2. Path Choice: Increased Attack Surface 380 One of the possible consequences of a path manipulation attack is an 381 increased attack surface. Thus, when the attack described in the 382 previous subsection is implemented, it may increase the potential of 383 other attacks to be performed. 385 3.2.6. Control Plane 387 3.2.6.1. Control or Signaling Packet Modification 389 An attacker can maliciously modify en route control packets in order 390 to disrupt or manipulate the DetNet path/resource allocation. 392 3.2.6.2. Control or Signaling Packet Injection 394 An attacker can maliciously inject control packets in order to 395 disrupt or manipulate the DetNet path/resource allocation. 397 3.2.7. Scheduling or Shaping 399 3.2.7.1. Reconnaissance 401 A passive eavesdropper can identify DetNet flows and then gather 402 information about en route DetNet flows, e.g., the number of DetNet 403 flows, their bandwidths, and their schedules. The gathered 404 information can later be used to invoke other attacks on some or all 405 of the flows. 407 Note that in some cases DetNet flows may be identified based on an 408 explicit DetNet header, but in some cases the flow identification may 409 be based on fields from the L3/L4 headers. If L3/L4 headers are 410 involved, for purposes of this draft we assume they are encrypted 411 and/or integrity-protected from external attackers. 413 3.2.8. Time Synchronization Mechanisms 415 An attacker can use any of the attacks described in [RFC7384] to 416 attack the synchronization protocol, thus affecting the DetNet 417 service. 419 3.3. Threat Summary 421 A summary of the attacks that were discussed in this section is 422 presented in Figure 1. For each attack, the table specifies the type 423 of attackers that may invoke the attack. In the context of this 424 summary, the distinction between internal and external attacks is 425 under the assumption that a corresponding security mechanism is being 426 used, and that the corresponding network equipment takes part in this 427 mechanism. 429 +-----------------------------------------+----+----+----+----+ 430 | Attack | Attacker Type | 431 | +---------+---------+ 432 | |Internal |External | 433 | |MITM|Inj.|MITM|Inj.| 434 +-----------------------------------------+----+----+----+----+ 435 |Delay attack | + | | + | | 436 +-----------------------------------------+----+----+----+----+ 437 |DetNet Flow Modification or Spoofing | + | + | | | 438 +-----------------------------------------+----+----+----+----+ 439 |Inter-segment Attack | + | + | | | 440 +-----------------------------------------+----+----+----+----+ 441 |Replication: Increased Attack Surface | + | + | + | + | 442 +-----------------------------------------+----+----+----+----+ 443 |Replication-related Header Manipulation | + | | | | 444 +-----------------------------------------+----+----+----+----+ 445 |Path Manipulation | + | + | | | 446 +-----------------------------------------+----+----+----+----+ 447 |Path Choice: Increased Attack Surface | + | + | + | + | 448 +-----------------------------------------+----+----+----+----+ 449 |Control or Signaling Packet Modification | + | | | | 450 +-----------------------------------------+----+----+----+----+ 451 |Control or Signaling Packet Injection | | + | | | 452 +-----------------------------------------+----+----+----+----+ 453 |Reconnaissance | + | | + | | 454 +-----------------------------------------+----+----+----+----+ 455 |Attacks on Time Sync Mechanisms | + | + | + | + | 456 +-----------------------------------------+----+----+----+----+ 458 Figure 1: Threat Analysis Summary 460 4. Security Threat Impacts 462 This section describes and rates the impact of the attacks described 463 in Section 3. In this section, the impacts as described assume that 464 the associated mitigation is not present or has failed. Mitigations 465 are discussed in Section 5. 467 In computer security, the impact (or consequence) of an incident can 468 be measured in loss of confidentiality, integrity or availability of 469 information. 471 DetNet raises these stakes significantly for OT applications, 472 particularly those which may have been designed to run in an OT-only 473 environment and thus may not have been designed for security in an IT 474 environment with its associated devices, services and protocols. 476 The severity of various components of the impact of a successful 477 vulnerability exploit to use cases by industry is available in more 478 detail in [I-D.ietf-detnet-use-cases]. Each of the use cases in the 479 DetNet Use Cases draft is represented in the table below, including 480 Pro Audio, Electrical Utilities, Industrial M2M (split into two 481 areas, M2M Data Gathering and M2M Control Loop), and others. 483 Components of Impact (left column) include Criticality of Failure, 484 Effects of Failure, Recovery, and DetNet Functional Dependence. 485 Criticality of failure summarizes the seriousness of the impact. The 486 impact of a resulting failure can affect many different metrics that 487 vary greatly in scope and severity. In order to reduce the number of 488 variables, only the following were included: Financial, Health and 489 Safety, People well being, Affect on a single organization, and 490 affect on multiple organizations. Recovery outlines how long it 491 would take for an affected use case to get back to its pre-failure 492 state (Recovery time objective, RTO), and how much of the original 493 service would be lost in between the time of service failure and 494 recovery to original state (Recovery Point Objective, RPO). DetNet 495 dependence maps how much the following DetNet service objectives 496 contribute to impact of failure: Time dependency, data integrity, 497 source node integrity, availability, latency/jitter. 499 The scale of the Impact mappings is low, medium, and high. In some 500 use cases there may be a multitude of specific applications in which 501 DetNet is used. For simplicity this section attempts to average the 502 varied impacts of different applications. This section does not 503 address the overall risk of a certain impact which would require the 504 likelihood of a failure happening. 506 In practice any such ratings will vary from case to case; the ratings 507 shown here are given as examples. 509 Table, Part One (of Two) 510 +------------------+-----------------------------------------+-----+ 511 | | Pro A | Util | Bldg |Wire- | Cell |M2M |M2M | 512 | | | | | less | |Data |Ctrl | 513 +------------------+-----------------------------------------+-----+ 514 | Criticality | Med | Hi | Low | Med | Med | Med | Med | 515 +------------------+-----------------------------------------+-----+ 516 | Effects 517 +------------------+-----------------------------------------+-----+ 518 | Financial | Med | Hi | Med | Med | Low | Med | Med | 519 +------------------+-----------------------------------------+-----+ 520 | Health/Safety | Med | Hi | Hi | Med | Med | Med | Med | 521 +------------------+-----------------------------------------+-----+ 522 | People WB | Med | Hi | Hi | Low | Hi | Low | Low | 523 +------------------+-----------------------------------------+-----+ 524 | Effect 1 org | Hi | Hi | Med | Hi | Med | Med | Med | 525 +------------------+-----------------------------------------+-----+ 526 | Effect >1 org | Med | Hi | Low | Med | Med | Med | Med | 527 +------------------+-----------------------------------------+-----+ 528 |Recovery 529 +------------------+-----------------------------------------+-----+ 530 | Recov Time Obj | Med | Hi | Med | Hi | Hi | Hi | Hi | 531 +------------------+-----------------------------------------+-----+ 532 | Recov Point Obj | Med | Hi | Low | Med | Low | Hi | Hi | 533 +------------------+-----------------------------------------+-----+ 534 |DetNet Dependence 535 +------------------+-----------------------------------------+-----+ 536 | Time Dependency | Hi | Hi | Low | Hi | Med | Low | Hi | 537 +------------------+-----------------------------------------+-----+ 538 | Latency/Jitter | Hi | Hi | Med | Med | Low | Low | Hi | 539 +------------------+-----------------------------------------+-----+ 540 | Data Integrity | Hi | Hi | Med | Hi | Low | Hi | Low | 541 +------------------+-----------------------------------------+-----+ 542 | Src Node Integ | Hi | Hi | Med | Hi | Med | Hi | Hi | 543 +------------------+-----------------------------------------+-----+ 544 | Availability | Hi | Hi | Med | Hi | Low | Hi | Hi | 545 +------------------+-----------------------------------------+-----+ 547 Table, Part Two (of Two) 548 +------------------+--------------------------+ 549 | | Mining | Block | Network | 550 | | | Chain | Slicing | 551 +------------------+--------------------------+ 552 | Criticality | Hi | Med | Hi | 553 +------------------+--------------------------+ 554 | Effects 555 +------------------+--------------------------+ 556 | Financial | Hi | Hi | Hi | 557 +------------------+--------------------------+ 558 | Health/Safety | Hi | Low | Med | 559 +------------------+--------------------------+ 560 | People WB | Hi | Low | Med | 561 +------------------+--------------------------+ 562 | Effect 1 org | Hi | Hi | Hi | 563 +------------------+--------------------------+ 564 | Effect >1 org | Hi | Low | Hi | 565 +------------------+--------------------------+ 566 |Recovery 567 +------------------+--------------------------+ 568 | Recov Time Obj | Hi | Low | Hi | 569 +------------------+--------------------------+ 570 | Recov Point Obj | Hi | Low | Hi | 571 +------------------+--------------------------+ 572 |DetNet Dependence 573 +------------------+--------------------------+ 574 | Time Dependency | Hi | Low | Hi | 575 +------------------+--------------------------+ 576 | Latency/Jitter | Hi | Low | Hi | 577 +------------------+--------------------------+ 578 | Data Integrity | Hi | Hi | Hi | 579 +------------------+--------------------------+ 580 | Src Node Integ | Hi | Hi | Hi | 581 +------------------+--------------------------+ 582 | Availability | Hi | Hi | Hi | 583 +------------------+--------------------------+ 585 Figure 2: Impact of Attacks by Use Case Industry 587 The rest of this section will cover impact of the different groups in 588 more detail. 590 4.1. Delay-Attacks 592 4.1.1. Data Plane Delay Attacks 594 Severely delayed messages in a DetNet link can result in the same 595 behavior as dropped messages in ordinary networks as the services 596 attached to the stream has strict deterministic requirements. 598 For a single path scenario, disruption is a real possibility, whereas 599 in a multipath scenario, large delays or instabilities in one stream 600 can lead to increased buffer and CPU resources on the elimination 601 bridge. 603 4.1.2. Control Plane Delay Attacks 605 In and of itself, this is not directly a threat to the DetNet 606 service, but the effects of delaying control messages can have quite 607 adverse effects later. 609 o Delayed tear-down can lead to resource leakage, which in turn can 610 result in failure to allocate new streams finally giving rise to a 611 denial of service attack. 613 o Failure to deliver, or severely delaying, signalling messages 614 adding an end-point to a multicast-group will prevent the new EP 615 from receiving expected frames thus disrupting expected behavior. 617 o Delaying messages removing an EP from a group can lead to loss of 618 privacy as the EP will continue to receive messages even after it 619 is supposedly removed. 621 4.2. Flow Modification and Spoofing 623 4.2.1. Flow Modification 625 ToDo. 627 4.2.2. Spoofing 629 4.2.2.1. Dataplane Spoofing 631 Spoofing dataplane messages can result in increased resource 632 consumptions on the bridges throughout the network as it will 633 increase buffer usage and CPU utilization. This can lead to resource 634 exhaustion and/or increased delay. 636 If the attacker manages to create valid headers, the false messages 637 can be forwarded through the network, using part of the allocated 638 bandwidth. This in turn can cause legitimate messages to be dropped 639 when the budget has been exhausted. 641 Finally, the endpoint will have to deal with invalid messages being 642 delivered to the endpoint instead of (or in addition to) a valid 643 message. 645 4.2.2.2. Control Plane Spoofing 647 A successful control plane spoofing-attack will potentionally have 648 adverse effects. It can do virtually anything from: 650 o modifying existing streams by changing the available bandwidth 652 o add or remove endpoints from a stream 654 o drop streams completly 656 o falsely create new streams (exhaust the systems resources, or to 657 enable streams outside the Network engineer's control) 659 4.3. Segmentation attacks (injection) 661 4.3.1. Data Plane Segmentation 663 Injection of false messages in a DetNet stream could lead to 664 exhaustion of the available bandwidth for a stream if the bridges 665 accounts false messages to the stream's budget. 667 In a multipath scenario, injected messages will cause increased CPU 668 utilization in elimination bridges. If enough paths are subject to 669 malicious injection, the legitimate messages can be dropped. 670 Likewise it can cause an increase in buffer usage. In total, it will 671 consume more resources in the bridges than normal, giving rise to a 672 resource exhaustion attack on the bridges. 674 If a stream is interrupted, the end application will be affected by 675 what is now a non-deterministic stream. 677 4.3.2. Control Plane segmentation 679 A successful Control Plane segmentation attack control messages to be 680 interpreted by nodes in the network, unbeknownst to the central 681 controller or the network engineer. This has the potential to create 683 o new streams (exhausting resources) 685 o drop existing (denial of service) 687 o add/remove end-stations to a multicast group (loss of privacy) 689 o modify the stream attributes (affecting available bandwidth 691 4.4. Replication and Elimination 693 The Replication and Elimination is relevant only to Data Plane 694 messages as Signalling is not subject to multipath routing. 696 4.4.1. Increased Attack Surface 698 Covered briefly in Section 4.3 700 4.4.2. Header Manipulation at Elimination Bridges 702 Covered briefly in Section 4.3 704 4.5. Control or Signaling Packet Modification 706 ToDo. 708 4.6. Control or Signaling Packet Injection 710 ToDo. 712 4.7. Reconnaissance 714 Of all the attacks, this is one of the most difficult to detect and 715 counter. Often, an attacker will start out by observing the traffic 716 going through the network and use the knowledge gathered in this 717 phase to mount future attacks. 719 The attacker can, at their leisure, observe over time all aspects of 720 the messaging and signalling, learning the intent and purpose of all 721 traffic flows. At some later date, possibly at an important time in 722 an operational context, the attacker can launch a multi-faceted 723 attack, possibly in conjunction with some demand for ransom. 725 The flow-id in the header of the data plane-messages gives an 726 attacker a very reliable identifier for DetNet traffic, and this 727 traffic has a high probability of going to lucrative targets. 729 4.8. Attacks on Time Sync Mechanisms 731 ToDo. 733 4.9. Attacks on Path Choice 735 This is covered in part in Section 4.3, and as with Replication and 736 Elimination (Section 4.4, this is relevant for DataPlane messages. 738 5. Security Threat Mitigation 740 This section describes a set of measures that can be taken to 741 mitigate the attacks described in Section 3. These mitigations 742 should be viewed as a toolset that includes several different and 743 diverse tools. Each application or system will typically use a 744 subset of these tools, based on a system-specific threat analysis. 746 5.1. Path Redundancy 748 Description 750 A DetNet flow that can be forwarded simultaneously over multiple 751 paths. Path replication and elimination 753 [I-D.ietf-detnet-architecture] provides resiliency to dropped or 754 delayed packets. This redundancy improves the robustness to 755 failures and to man-in-the-middle attacks. 757 Related attacks 759 Path redundancy can be used to mitigate various man-in-the-middle 760 attacks, including attacks described in Section 3.2.1, 761 Section 3.2.2, Section 3.2.3, and Section 3.2.8. 763 5.2. Integrity Protection 765 Description 767 An integrity protection mechanism, such as a Hash-based Message 768 Authentication Code (HMAC) can be used to mitigate modification 769 attacks. Integrity protection can be used on the data plane 770 header, to prevent its modification and tampering. Integrity 771 protection in the control plane is discussed in Section 5.5. 773 Related attacks 775 Integrity protection mitigates attacks related to modification and 776 tampering, including the attacks described in Section 3.2.2 and 777 Section 3.2.4. 779 5.3. DetNet Node Authentication 781 Description 783 Source authentication verifies the authenticity of DetNet sources, 784 allowing to mitigate spoofing attacks. Note that while integrity 785 protection (Section 5.2) prevents intermediate nodes from 786 modifying information, authentication verfies the source of the 787 information. 789 Related attacks 791 DetNet node authentication is used to mitigate attacks related to 792 spoofing, including the attacks of Section 3.2.2, and 793 Section 3.2.4. 795 5.4. Encryption 797 Description 799 DetNet flows can be forwarded in encrypted form. 801 Related attacks 803 While confidentiality is not considered an important goal with 804 respect to DetNet, encryption can be used to mitigate recon 805 attacks (Section 3.2.7). 807 5.5. Control and Signaling Message Protection 809 Description 811 Control and sigaling messages can be protected using 812 authentication and integrity protection mechanisms. 814 Related attacks 816 These mechanisms can be used to mitigate various attacks on the 817 control plane, as described in Section 3.2.6, Section 3.2.8 and 818 Section 3.2.5. 820 5.6. Dynamic Performance Analytics 822 Description 824 Information about the network performance can be gathered in real- 825 time in order to detect anomalies and unusual behavior that may be 826 the symptom of a security attack. The gathered information can be 827 based, for example, on per-flow counters, bandwidth measurement, 828 and monitoring of packet arrival times. Unusual behavior or 829 potentially malicious nodes can be reported to a management 830 system, or can be used as a trigger for taking corrective actions. 831 The information can be tracked by DetNet end systems and transit 832 nodes, and exported to a management system, for example using 833 NETCONF. 835 Related attacks 837 Performance analytics can be used to mitigate various attacks, 838 including the ones described in Section 3.2.1, Section 3.2.3, and 839 Section 3.2.8. 841 5.7. Mitigation Summary 843 The following table maps the attacks of Section 3 to the impacts of 844 Section 4, and to the mitigations of the current section. Each row 845 specifies an attack, the impact of this attack if it is successfully 846 implemented, and possible mitigation methods. 848 +----------------------+---------------------+---------------------+ 849 | Attack | Impact | Mitigations | 850 +----------------------+---------------------+---------------------+ 851 |Delay Attack |-Non-deterministic |-Path redundancy | 852 | | delay |-Performance | 853 | |-Data disruption | analytics | 854 | |-Increased resource | | 855 | | consumption | | 856 +----------------------+---------------------+---------------------+ 857 |Reconnaissance |-Enabler for other |-Encryption | 858 | | attacks | | 859 +----------------------+---------------------+---------------------+ 860 |DetNet Flow Modificat-|-Increased resource |-Path redundancy | 861 |ion or Spoofing | consumption |-Integrity protection| 862 | |-Data disruption |-DetNet Node | 863 | | | authentication | 864 +----------------------+---------------------+---------------------+ 865 |Inter-Segment Attack |-Increased resource |-Path redundancy | 866 | | consumption |-Performance | 867 | |-Data disruption | analytics | 868 +----------------------+---------------------+---------------------+ 869 |Replication: Increased|-All impacts of other|-Integrity protection| 870 |attack surface | attacks |-DetNet Node | 871 | | | authentication | 872 +----------------------+---------------------+---------------------+ 873 |Replication-related |-Non-deterministic |-Integrity protection| 874 |Header Manipulation | delay |-DetNet Node | 875 | |-Data disruption | authentication | 876 +----------------------+---------------------+---------------------+ 877 |Path Manipulation |-Enabler for other |-Control message | 878 | | attacks | protection | 879 +----------------------+---------------------+---------------------+ 880 |Path Choice: Increased|-All impacts of other|-Control message | 881 |Attack Surface | attacks | protection | 882 +----------------------+---------------------+---------------------+ 883 |Control or Signaling |-Increased resource |-Control message | 884 |Packet Modification | consumption | protection | 885 | |-Non-deterministic | | 886 | | delay | | 887 | |-Data disruption | | 888 +----------------------+---------------------+---------------------+ 889 |Control or Signaling |-Increased resource |-Control message | 890 |Packet Injection | consumption | protection | 891 | |-Non-deterministic | | 892 | | delay | | 893 | |-Data disruption | | 894 +----------------------+---------------------+---------------------+ 895 |Attacks on Time Sync |-Non-deterministic |-Path redundancy | 896 |Mechanisms | delay |-Control message | 897 | |-Increased resource | protection | 898 | | consumption |-Performance | 899 | |-Data disruption | analytics | 900 +----------------------+---------------------+---------------------+ 902 Figure 3: Mapping Attacks to Impact and Mitigations 904 6. Association of Attacks to Use Cases 906 Different attacks can have different impact and/or mitigation 907 depending on the use case, so we would like to make this association 908 in our analysis. However since there is a potentially unbounded list 909 of use cases, we categorize the attacks with respect to the common 910 themes of the use cases as identified in the Use Case Common Themes 911 section of the DetNet Use Cases draft [I-D.ietf-detnet-use-cases]. 913 See also Figure 2 for a mapping of the impact of attacks per use case 914 by industry. 916 6.1. Use Cases by Common Themes 918 In this section we review each theme and discuss the attacks that are 919 applicable to that theme, as well as anything specific about the 920 impact and mitigations for that attack with respect to that theme. 921 The table Figure 5 then provides a summary of the attacks that are 922 applicable to each theme. 924 6.1.1. Network Layer - AVB/TSN Ethernet 926 DetNet is expected to run over various transmission mediums, with 927 Ethernet being explicitly supported. Attacks such as Delay or 928 Reconnaissance might be implemented differently on a different 929 transmission medium, however the impact on the DetNet as a whole 930 would be essentially the same. We thus conclude that all attacks and 931 impacts that would be applicable to DetNet over Ethernet (i.e. all 932 those named in this draft) would also be applicable to DetNet over 933 other transmission mediums. 935 With respect to mitigations, some methods are specific to the 936 Ethernet medium, for example time-aware scheduling using 802.1Qbv can 937 protect against excessive use of bandwidth at the ingress - for other 938 mediums, other mitigations would have to be implemented to provide 939 analogous protection. 941 6.1.2. Central Administration 943 A DetNet network is expected to be controlled by a centralized 944 network configuration and control system (CNC). Such a system may be 945 in a single central location, or it may be distributed across 946 multiple control entities that function together as a unified control 947 system for the network. 949 In this draft we distinguish between attacks on the DetNet Control 950 plane vs. Data plane. But is an attack affecting control plane 951 packets synonymous with an attack on the CNC itself? For purposes of 952 this draft let us consider an attack on the CNC itself to be out of 953 scope, and consider all attacks named in this draft which are 954 relevant to control plane packets to be relevant to this theme, 955 including Path Manipulation, Path Choice, Control Packet Modification 956 or Injection, Reconaissance and Attacks on Time Sync Mechanisms. 958 6.1.3. Hot Swap 960 A DetNet network is not expected to be "plug and play" - it is 961 expected that there is some centralized network configuration and 962 control system. However, the ability to "hot swap" components (e.g. 963 due to malfunction) is similar enough to "plug and play" that this 964 kind of behavior may be expected in DetNet networks, depending on the 965 implementation. 967 An attack surface related to Hot Swap is that the DetNet network must 968 at least consider input at runtime from devices that were not part of 969 the initial configuration of the network. Even a "perfect" (or 970 "hitless") replacement of a device at runtime would not necessarily 971 be ideal, since presumably one would want to distinguish it from the 972 original for OAM purposes (e.g. to report hot swap of a failed 973 device). 975 This implies that an attack such as Flow Modification, Spoofing or 976 Inter-segment (which could introduce packets from a "new" device 977 (i.e. one heretofore unknown on the network) could be used to exploit 978 the need to consider such packets (as opposed to rejecting them out 979 of hand as one would do if one did not have to consider introduction 980 of a new device). 982 Similarly if the network was designed to support runtime replacement 983 of a clock device, then presence (or apparent presence) and thus 984 consideration of packets from a new such device could affect the 985 network, or the time sync of the network, for example by initiating a 986 new Best Master Clock selection process. Thus attacks on time sync 987 should be considered when designing hot swap type functionality. 989 6.1.4. Data Flow Information Models 991 Data Flow Information Models specific to DetNet networks are to be 992 specified by DetNet. Thus they are "new" and thus potentially 993 present a new attack surface. Does the threat take advantage of any 994 aspect of our new Data Flow Info Models? 996 This is TBD, thus there are no specific entries in our table, however 997 that does not imply that there could be no relevant attacks. 999 6.1.5. L2 and L3 Integration 1001 A DetNet network integrates Layer 2 (bridged) networks (e.g. AVB/TSN 1002 LAN) and Layer 3 (routed) networks via the use of well-known 1003 protocols such as IPv6, MPLS-PW, and Ethernet. Presumably security 1004 considerations applicable directly to those individual protocols is 1005 not specific to DetNet, and thus out of scope for this draft. 1006 However enabling DetNet to coordinate Layer 2 and Layer 3 behavior 1007 will require some additions to existing protocols (see draft-dt- 1008 detnet-dp-alt) and any such new work can introduce new attack 1009 surfaces. 1011 This is TBD, thus there are no specific entries in our table, however 1012 that does not imply that there could be no relevant attacks. 1014 6.1.6. End-to-End Delivery 1016 Packets sent over DetNet are guaranteed not to be dropped by the 1017 network due to congestion. (Packets may however be dropped for 1018 intended reasons, e.g. per security measures). 1020 A Data plane attack may force packets to be dropped, for example a 1021 "long" Delay or Replication/Elimination or Flow Modification attack. 1023 The same result might be obtained by a Control plane attack, e.g. 1024 Path Manipulation or Signaling Packet Modification. 1026 It may be that such attacks are limited to Internal MITM attackers, 1027 but other possibilities should be considered. 1029 An attack may also cause packets that should not be delivered to be 1030 delivered, such as by forcing packets from one (e.g. replicated) path 1031 to be preferred over another path when they should not be 1032 (Replication attack), or by Flow Modification, or by Path Choice or 1033 Packet Injection. A Time Sync attack could cause a system that was 1034 expecting certain packets at certain times to accept unintended 1035 packets based on compromised system time or time windowing in the 1036 scheduler. 1038 6.1.7. Proprietary Deterministic Ethernet Networks 1040 There are many proprietary non-interoperable deterministic Ethernet- 1041 based networks currently available; DetNet is intended to provide an 1042 open-standards-based alternative to such networks. In cases where a 1043 DetNet intersects with remnants of such networks or their protocols, 1044 such as by protocol emulation or access to such a network via a 1045 gateway, new attack surfaces can be opened. 1047 For example an Inter-Segment or Control plane attack such as Path 1048 Manipulation, Path Choice or Control Packet Modification/Injection 1049 could be used to exploit commands specific to such a protocol, or 1050 that are interpreted differently by the different protocols or 1051 gateway. 1053 6.1.8. Replacement for Proprietary Fieldbuses 1055 There are many proprietary "field buses" used in today's industrial 1056 and other industries; DetNet is intended to provide an open- 1057 standards-based alternative to such buses. In cases where a DetNet 1058 intersects with such fieldbuses or their protocols, such as by 1059 protocol emulation or access via a gateway, new attack surfaces can 1060 be opened. 1062 For example an Inter-Segment or Control plane attack such as Path 1063 Manipulation, Path Choice or Control Packet Modification/Injection 1064 could be used to exploit commands specific to such a protocol, or 1065 that are interpreted differently by the different protocols or 1066 gateway. 1068 6.1.9. Deterministic vs Best-Effort Traffic 1070 DetNet is intended to support coexistence of time-sensitive 1071 operational (OT, deterministic) traffic and information (IT, "best 1072 effort") traffic on the same ("unified") network. 1074 The presence of IT traffic on a network carrying OT traffic has long 1075 been considered insecure design [reference needed here]. With 1076 DetNet, this coexistance will become more common, and mitigations 1077 will need to be established. The fact that the IT traffic on a 1078 DetNet is limited to a corporate controlled network makes this a less 1079 difficult problem compared to being exposed to the open Internet, 1080 however this aspect of DetNet security should not be underestimated. 1082 Most of the themes described in this draft address OT (reserved) 1083 streams - this item is intended to address issues related to IT 1084 traffic on a DetNet. 1086 An Inter-segment attack can flood the network with IT-type traffic 1087 with the intent of disrupting handling of IT traffic, and/or the goal 1088 of interfering with OT traffic. Presumably if the stream reservation 1089 and isolation of the DetNet is well-designed (better-designed than 1090 the attack) then interference with OT traffic should not result from 1091 an attack that floods the network with IT traffic. 1093 However the DetNet's handling of IT traffic may not (by design) be as 1094 resilient to DOS attack, and thus designers must be otherwise 1095 prepared to mitigate DOS attacks on IT traffic in a DetNet. 1097 6.1.10. Deterministic Flows 1099 Reserved bandwidth data flows (deterministic flows) must provide the 1100 allocated bandwidth, and must be isolated from each other. 1102 A Spoofing or Inter-segment attack which adds packet traffic to a 1103 bandwidth-reserved stream could cause that stream to occupy more 1104 bandwidth than it is allocated, resulting in interference with other 1105 deterministic flows. 1107 A Flow Modification or Spoofing or Header Manipulation or Control 1108 Packet Modification attack could cause packets from one flow to be 1109 directed to another flow, thus breaching isolation between the flows. 1111 6.1.11. Unused Reserved Bandwidth 1113 If bandwidth reservations are made for a stream but the associated 1114 bandwidth is not used at any point in time, that bandwidth is made 1115 available on the network for best-effort traffic. If the owner of 1116 the reserved stream then starts transmitting again, the bandwidth is 1117 no longer available for best-effort traffic, on a moment-to-moment 1118 basis. (Such "temporarily available" bandwidth is not available for 1119 time-sensitive traffic, which must have its own reservation). 1121 An Inter-segment attack could flood the network with IT traffic, 1122 interfering with the intended IT traffic. 1124 A Flow Modification or Spoofing or Control Packet Modification or 1125 Injection attack could cause extra bandwidth to be reserved by a new 1126 or existing stream, thus making it unavailable for use by best-effort 1127 traffic. 1129 6.1.12. Interoperability 1131 The DetNet network specifications are intended to enable an ecosystem 1132 in which multiple vendors can create interoperable products, thus 1133 promoting device diversity and potentially higher numbers of each 1134 device manufactured. Does the threat take advantage of differences 1135 in implementation of "interoperable" products made by different 1136 vendors? 1138 This is TBD, thus there are no specific entries in our table, however 1139 that does not imply that there could be no relevant attacks. 1141 6.1.13. Cost Reductions 1143 The DetNet network specifications are intended to enable an ecosystem 1144 in which multiple vendors can create interoperable products, thus 1145 promoting higher numbers of each device manufactured, promoting cost 1146 reduction and cost competition among vendors. Does the threat take 1147 advantage of "low cost" HW or SW components or other "cost-related 1148 shortcuts" that might be present in devices? 1150 This is TBD, thus there are no specific entries in our table, however 1151 that does not imply that there could be no relevant attacks. 1153 6.1.14. Insufficiently Secure Devices 1155 The DetNet network specifications are intended to enable an ecosystem 1156 in which multiple vendors can create interoperable products, thus 1157 promoting device diversity and potentially higher numbers of each 1158 device manufactured. Does the threat attack "naivete" of SW, for 1159 example SW that was not designed to be sufficiently secure (or secure 1160 at all) but is deployed on a DetNet network that is intended to be 1161 highly secure? (For example IoT exploits like the Mirai video-camera 1162 botnet ([MIRAI]). 1164 This is TBD, thus there are no specific entries in our table, however 1165 that does not imply that there could be no relevant attacks. 1167 6.1.15. DetNet Network Size 1169 DetNet networks range in size from very small, e.g. inside a single 1170 industrial machine, to very large, for example a Utility Grid network 1171 spanning a whole country. 1173 The size of the network might be related to how the attack is 1174 introduced into the network, for example if the entire network is 1175 local, there is a threat that power can be cut to the entire network. 1176 If the network is large, perhaps only a part of the network is 1177 attacked. 1179 A Delay attack might be as relevant to a small network as to a large 1180 network, although the amount of delay might be different. 1182 Attacks sourced from IT traffic might be more likely in large 1183 networks, since more people might have access to the network. 1184 Similarly Path Manipulation, Path Choice and Time Sync attacks seem 1185 more likely relevant to large networks. 1187 6.1.16. Multiple Hops 1189 Large DetNet networks (e.g. a Utility Grid network) may involve many 1190 "hops" over various kinds of links for example radio repeaters, 1191 microwave links, fiber optic links, etc.. 1193 An attack that takes advantage of flaws (or even normal operation) in 1194 the device drivers for the various links (through internal knowledge 1195 of how the individual driver or firmware operates, perhaps like the 1196 Stuxnet attack) could take proportionately greater advantage of this 1197 topology. We don't currently have an attack like this defined; we 1198 have only "protocol" (time or packet) based attacks. Perhaps we need 1199 to define an attack like this? Or is that out of scope for DetNet? 1201 It is also possible that this DetNet topology will not be in as 1202 common use as other more homogeneous topologies so there may be more 1203 opportunity for attackers to exploit software and/or protocol flaws 1204 in the implementations which have not been wrung out by extensive 1205 use, particularly in the case of early adopters. 1207 Of the attacks we have defined, the ones identified above as relevant 1208 to "large" networks seem to be most relevant. 1210 6.1.17. Level of Service 1212 A DetNet is expected to provide means to configure the network that 1213 include querying network path latency, requesting bounded latency for 1214 a given stream, requesting worst case maximum and/or minimum latency 1215 for a given path or stream, and so on. It is an expected case that 1216 the network cannot provide a given requested service level. In such 1217 cases the network control system should reply that the requested 1218 service level is not available (as opposed to accepting the parameter 1219 but then not delivering the desired behavior). 1221 Control plane attacks such as Signaling Packet Modification and 1222 Injection could be used to modify or create control traffic that 1223 could interfere with the process of a user requesting a level of 1224 service and/or the network's reply. 1226 Reconnaissance could be used to characterize flows and perhaps target 1227 specific flows for attack via the Control plane as noted above. 1229 6.1.18. Bounded Latency 1231 DetNet provides the expectation of guaranteed bounded latency. 1233 Delay attacks can cause packets to miss their agreed-upon latency 1234 boundaries. 1236 Time Sync attacks can corrupt the system's time reference, resulting 1237 in missed latency deadlines (with respect to the "correct" time 1238 reference). 1240 6.1.19. Low Latency 1242 Applications may require "extremely low latency" however depending on 1243 the application these may mean very different latency values; for 1244 example "low latency" across a Utility grid network is on a different 1245 time scale than "low latency" in a motor control loop in a small 1246 machine. The intent is that the mechanisms for specifying desired 1247 latency include wide ranges, and that architecturally there is 1248 nothing to prevent arbitrarily low latencies from being implemented 1249 in a given network. 1251 Attacks on the Control plane (as described in the Level of Service 1252 theme) and Delay and Time attacks (as described in the Bounded 1253 Latency theme) both apply here. 1255 6.1.20. Bounded Jitter (Latency Variation) 1257 DetNet is expected to provide bounded jitter (packet to packet 1258 latency variation). 1260 Delay attacks can cause packets to vary in their arrival times, 1261 resulting in packet to packet latency variation, thereby violating 1262 the jitter specification. 1264 6.1.21. Symmetrical Path Delays 1266 Some applications would like to specify that the transit delay time 1267 values be equal for both the transmit and return paths. 1269 Delay attacks can cause path delays to differ. 1271 Time Sync attacks can corrupt the system's time reference, resulting 1272 in differing path delays (with respect to the "correct" time 1273 reference). 1275 6.1.22. Reliability and Availability 1277 DetNet based systems are expected to be implemented with essentially 1278 arbitrarily high availability (for example 99.9999% up time, or even 1279 12 nines). The intent is that the DetNet designs should not make any 1280 assumptions about the level of reliability and availability that may 1281 be required of a given system, and should define parameters for 1282 communicating these kinds of metrics within the network. 1284 Any attack on the system, of any type, can affect its overall 1285 reliability and availability, thus in our table we have marked every 1286 attack. Since every DetNet depends to a greater or lesser degree on 1287 reliability and availability, this essentially means that all 1288 networks have to mitigate all attacks, which to a greater or lesser 1289 degree defeats the purpose of associating attacks with use cases. It 1290 also underscores the difficulty of designing "extremely high 1291 reliability" networks. I hope that in future drafts we can say 1292 something more useful here. 1294 6.1.23. Redundant Paths 1296 DetNet based systems are expected to be implemented with essentially 1297 arbitrarily high reliability/availability. A strategy used by DetNet 1298 for providing such extraordinarily high levels of reliability is to 1299 provide redundant paths that can be seamlessly switched between, all 1300 the while maintaining the required performance of that system. 1302 Replication-related attacks are by definition applicable here. 1303 Control plane attacks can also interfere with the configuration of 1304 redundant paths. 1306 6.1.24. Security Measures 1308 A DetNet network must be made secure against devices failures, 1309 attackers, misbehaving devices, and so on. Does the threat affect 1310 such security measures themselves, e.g. by attacking SW designed to 1311 protect against device failure? 1313 This is TBD, thus there are no specific entries in our table, however 1314 that does not imply that there could be no relevant attacks. 1316 6.2. Attack Types by Use Case Common Theme 1318 The following table lists the attacks of Section 3, assigning a 1319 number to each type of attack. That number is then used as a short 1320 form identifier for the attack in Figure 5. 1322 +--+----------------------------------------+----------------------+ 1323 | | Attack | Section | 1324 +--+----------------------------------------+----------------------+ 1325 | 1|Delay Attack | Section 3.2.1 | 1326 +--+----------------------------------------+----------------------+ 1327 | 2|DetNet Flow Modification or Spoofing | Section 3.2.2 | 1328 +--+----------------------------------------+----------------------+ 1329 | 3|Inter-Segment Attack | Section 3.2.3 | 1330 +--+----------------------------------------+----------------------+ 1331 | 4|Replication: Increased attack surface | Section 3.2.4.1 | 1332 +--+----------------------------------------+----------------------+ 1333 | 5|Replication-related Header Manipulation | Section 3.2.4.2 | 1334 +--+----------------------------------------+----------------------+ 1335 | 6|Path Manipulation | Section 3.2.5.1 | 1336 +--+----------------------------------------+----------------------+ 1337 | 7|Path Choice: Increased Attack Surface | Section 3.2.5.2 | 1338 +--+----------------------------------------+----------------------+ 1339 | 8|Control or Signaling Packet Modification| Section 3.2.6.1 | 1340 +--+----------------------------------------+----------------------+ 1341 | 9|Control or Signaling Packet Injection | Section 3.2.6.2 | 1342 +--+----------------------------------------+----------------------+ 1343 |10|Reconnaissance | Section 3.2.7 | 1344 +--+----------------------------------------+----------------------+ 1345 |11|Attacks on Time Sync Mechanisms | Section 3.2.8 | 1346 +--+----------------------------------------+----------------------+ 1348 Figure 4: List of Attacks 1350 The following table maps the use case themes presented in this memo 1351 to the attacks of Figure 4. Each row specifies a theme, and the 1352 attacks relevant to this theme are marked with a '+'. 1354 +----------------------------+--------------------------------+ 1355 | Theme | Attack | 1356 | +--+--+--+--+--+--+--+--+--+--+--+ 1357 | | 1| 2| 3| 4| 5| 6| 7| 8| 9|10|11| 1358 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1359 |Network Layer - AVB/TSN Eth.| +| +| +| +| +| +| +| +| +| +| +| 1360 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1361 |Central Administration | | | | | | +| +| +| +| +| +| 1362 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1363 |Hot Swap | | +| +| | | | | | | | +| 1364 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1365 |Data Flow Information Models| | | | | | | | | | | | 1366 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1367 |L2 and L3 Integration | | | | | | | | | | | | 1368 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1369 |End-to-end Delivery | +| +| +| +| +| +| +| +| +| | +| 1370 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1371 |Proprietary Deterministic | | | +| | | +| +| +| +| | | 1372 |Ethernet Networks | | | | | | | | | | | | 1373 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1374 |Replacement for Proprietary | | | +| | | +| +| +| +| | | 1375 |Fieldbuses | | | | | | | | | | | | 1376 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1377 |Deterministic vs. Best- | | | +| | | | | | | | | 1378 |Effort Traffic | | | | | | | | | | | | 1379 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1380 |Deterministic Flows | | +| +| | +| +| | +| | | | 1381 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1382 |Unused Reserved Bandwidth | | +| +| | | | | +| +| | | 1383 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1384 |Interoperability | | | | | | | | | | | | 1385 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1386 |Cost Reductions | | | | | | | | | | | | 1387 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1388 |Insufficiently Secure | | | | | | | | | | | | 1389 |Devices | | | | | | | | | | | | 1390 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1391 |DetNet Network Size | +| | | | | +| +| | | | +| 1392 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1393 |Multiple Hops | +| +| | | | +| +| | | | +| 1394 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1395 |Level of Service | | | | | | | | +| +| +| | 1396 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1397 |Bounded Latency | +| | | | | | | | | | +| 1398 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1399 |Low Latency | +| | | | | | | +| +| +| +| 1400 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1401 |Bounded Jitter | +| | | | | | | | | | | 1402 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1403 |Symmetric Path Delays | +| | | | | | | | | | +| 1404 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1405 |Reliability and Availability| +| +| +| +| +| +| +| +| +| +| +| 1406 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1407 |Redundant Paths | | | | +| +| | | +| +| | | 1408 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1409 |Security Measures | | | | | | | | | | | | 1410 +----------------------------+--+--+--+--+--+--+--+--+--+--+--+ 1412 Figure 5: Mapping Between Themes and Attacks 1414 6.3. Security Considerations for OAM Traffic 1416 This section considers DetNet-specific security considerations for 1417 packet traffic that is generated and transmitted over a DetNet as 1418 part of OAM (Operations, Administration and Maintenance). For 1419 purposes of this discussion, OAM traffic falls into one of two basic 1420 types: 1422 o OAM traffic generated by the network itself. The additional 1423 bandwidth required for such packets is added by the network 1424 administration, presumably transparent to the customer. Security 1425 considerations for such traffic are not DetNet-specific (apart 1426 from such traffic being subject to the same DetNet-specific 1427 security considerations as any other DetNet data flow) and are 1428 thus not covered in this document. 1430 o OAM traffic generated by the customer. From a DetNet security 1431 point of view, DetNet security considerations for such traffic are 1432 exactly the same as for any other customer data flows. 1434 Thus OAM traffic presents no additional (i.e. OAM-specific) DetNet 1435 security considerations. 1437 7. Appendix A: DetNet Draft Security-Related Statements 1439 This section collects the various statements in the currently 1440 existing DetNet Working Group drafts. For each draft, the section 1441 name and number of the quoted section is shown. The text shown here 1442 is the work of the original draft authors, quoted verbatim from the 1443 drafts. The intention is to explicitly quote all relevant text, not 1444 to summarize it. 1446 7.1. Architecture (draft 8) 1448 7.1.1. Fault Mitigation (sec 4.5) 1450 One key to building robust real-time systems is to reduce the 1451 infinite variety of possible failures to a number that can be 1452 analyzed with reasonable confidence. DetNet aids in the process by 1453 providing filters and policers to detect DetNet packets received on 1454 the wrong interface, or at the wrong time, or in too great a volume, 1455 and to then take actions such as discarding the offending packet, 1456 shutting down the offending DetNet flow, or shutting down the 1457 offending interface. 1459 It is also essential that filters and service remarking be employed 1460 at the network edge to prevent non-DetNet packets from being mistaken 1461 for DetNet packets, and thus impinging on the resources allocated to 1462 DetNet packets. 1464 There exist techniques, at present and/or in various stages of 1465 standardization, that can perform these fault mitigation tasks that 1466 deliver a high probability that misbehaving systems will have zero 1467 impact on well-behaved DetNet flows, except of course, for the 1468 receiving interface(s) immediately downstream of the misbehaving 1469 device. Examples of such techniques include traffic policing 1470 functions (e.g. [RFC2475]) and separating flows into per-flow rate- 1471 limited queues. 1473 7.1.2. Security Considerations (sec 7) 1475 Security in the context of Deterministic Networking has an added 1476 dimension; the time of delivery of a packet can be just as important 1477 as the contents of the packet, itself. A man-in-the-middle attack, 1478 for example, can impose, and then systematically adjust, additional 1479 delays into a link, and thus disrupt or subvert a real-time 1480 application without having to crack any encryption methods employed. 1481 See [RFC7384] for an exploration of this issue in a related context. 1483 Furthermore, in a control system where millions of dollars of 1484 equipment, or even human lives, can be lost if the DetNet QoS is not 1485 delivered, one must consider not only simple equipment failures, 1486 where the box or wire instantly becomes perfectly silent, but bizarre 1487 errors such as can be caused by software failures. Because there is 1488 essential no limit to the kinds of failures that can occur, 1489 protecting against realistic equipment failures is indistinguishable, 1490 in most cases, from protecting against malicious behavior, whether 1491 accidental or intentional. 1493 Security must cover: 1495 o Protection of the signaling protocol 1497 o Authentication and authorization of the controlling nodes 1499 o Identification and shaping of the flows 1501 7.2. Data Plane Alternatives (draft 4) 1503 7.2.1. Security Considerations (sec 7) 1505 This document does not add any new security considerations beyond 1506 what the referenced technologies already have. 1508 7.3. Problem Statement (draft 5) 1510 7.3.1. Security Considerations (sec 5) 1512 Security in the context of Deterministic Networking has an added 1513 dimension; the time of delivery of a packet can be just as important 1514 as the contents of the packet, itself. A man-in-the-middle attack, 1515 for example, can impose, and then systematically adjust, additional 1516 delays into a link, and thus disrupt or subvert a real-time 1517 application without having to crack any encryption methods employed. 1518 See [RFC7384] for an exploration of this issue in a related context. 1520 Typical control networks today rely on complete physical isolation to 1521 prevent rogue access to network resources. DetNet enables the 1522 virtualization of those networks over a converged IT/OT 1523 infrastructure. Doing so, DetNet introduces an additional risk that 1524 flows interact and interfere with one another as they share physical 1525 resources such as Ethernet trunks and radio spectrum. The 1526 requirement is that there is no possible data leak from and into a 1527 deterministic flow, and in a more general fashion there is no 1528 possible influence whatsoever from the outside on a deterministic 1529 flow. The expectation is that physical resources are effectively 1530 associated with a given flow at a given point of time. In that 1531 model, Time Sharing of physical resources becomes transparent to the 1532 individual flows which have no clue whether the resources are used by 1533 other flows at other times. 1535 Security must cover: 1537 o Protection of the signaling protocol 1539 o Authentication and authorization of the controlling nodes 1541 o Identification and shaping of the flows 1543 o Isolation of flows from leakage and other influences from any 1544 activity sharing physical resources 1546 7.4. Use Cases (draft 11) 1548 7.4.1. (Utility Networks) Security Current Practices and Limitations 1549 (sec 3.2.1) 1551 Grid monitoring and control devices are already targets for cyber 1552 attacks, and legacy telecommunications protocols have many intrinsic 1553 network-related vulnerabilities. For example, DNP3, Modbus, 1554 PROFIBUS/PROFINET, and other protocols are designed around a common 1555 paradigm of request and respond. Each protocol is designed for a 1556 master device such as an HMI (Human Machine Interface) system to send 1557 commands to subordinate slave devices to retrieve data (reading 1558 inputs) or control (writing to outputs). Because many of these 1559 protocols lack authentication, encryption, or other basic security 1560 measures, they are prone to network-based attacks, allowing a 1561 malicious actor or attacker to utilize the request-and-respond system 1562 as a mechanism for command-and-control like functionality. Specific 1563 security concerns common to most industrial control, including 1564 utility telecommunication protocols include the following: 1566 o Network or transport errors (e.g. malformed packets or excessive 1567 latency) can cause protocol failure. 1569 o Protocol commands may be available that are capable of forcing 1570 slave devices into inoperable states, including powering-off 1571 devices, forcing them into a listen-only state, disabling 1572 alarming. 1574 o Protocol commands may be available that are capable of restarting 1575 communications and otherwise interrupting processes. 1577 o Protocol commands may be available that are capable of clearing, 1578 erasing, or resetting diagnostic information such as counters and 1579 diagnostic registers. 1581 o Protocol commands may be available that are capable of requesting 1582 sensitive information about the controllers, their configurations, 1583 or other need-to-know information. 1585 o Most protocols are application layer protocols transported over 1586 TCP; therefore it is easy to transport commands over non-standard 1587 ports or inject commands into authorized traffic flows. 1589 o Protocol commands may be available that are capable of 1590 broadcasting messages to many devices at once (i.e. a potential 1591 DoS). 1593 o Protocol commands may be available to query the device network to 1594 obtain defined points and their values (i.e. a configuration 1595 scan). 1597 o Protocol commands may be available that will list all available 1598 function codes (i.e. a function scan). 1600 o These inherent vulnerabilities, along with increasing connectivity 1601 between IT an OT networks, make network-based attacks very 1602 feasible. 1604 o Simple injection of malicious protocol commands provides control 1605 over the target process. Altering legitimate protocol traffic can 1606 also alter information about a process and disrupt the legitimate 1607 controls that are in place over that process. A man-in-the-middle 1608 attack could provide both control over a process and 1609 misrepresentation of data back to operator consoles. 1611 7.4.2. (Utility Networks) Security Trends in Utility Networks (sec 1612 3.3.3) 1614 Although advanced telecommunications networks can assist in 1615 transforming the energy industry by playing a critical role in 1616 maintaining high levels of reliability, performance, and 1617 manageability, they also introduce the need for an integrated 1618 security infrastructure. Many of the technologies being deployed to 1619 support smart grid projects such as smart meters and sensors can 1620 increase the vulnerability of the grid to attack. Top security 1621 concerns for utilities migrating to an intelligent smart grid 1622 telecommunications platform center on the following trends: 1624 o Integration of distributed energy resources 1626 o Proliferation of digital devices to enable management, automation, 1627 protection, and control 1629 o Regulatory mandates to comply with standards for critical 1630 infrastructure protection 1632 o Migration to new systems for outage management, distribution 1633 automation, condition-based maintenance, load forecasting, and 1634 smart metering 1636 o Demand for new levels of customer service and energy management 1638 This development of a diverse set of networks to support the 1639 integration of microgrids, open-access energy competition, and the 1640 use of network-controlled devices is driving the need for a converged 1641 security infrastructure for all participants in the smart grid, 1642 including utilities, energy service providers, large commercial and 1643 industrial, as well as residential customers. Securing the assets of 1644 electric power delivery systems (from the control center to the 1645 substation, to the feeders and down to customer meters) requires an 1646 end-to-end security infrastructure that protects the myriad of 1647 telecommunications assets used to operate, monitor, and control power 1648 flow and measurement. 1650 "Cyber security" refers to all the security issues in automation and 1651 telecommunications that affect any functions related to the operation 1652 of the electric power systems. Specifically, it involves the 1653 concepts of: 1655 o Integrity : data cannot be altered undetectably 1657 o Authenticity : the telecommunications parties involved must be 1658 validated as genuine 1660 o Authorization : only requests and commands from the authorized 1661 users can be accepted by the system 1663 o Confidentiality : data must not be accessible to any 1664 unauthenticated users 1666 When designing and deploying new smart grid devices and 1667 telecommunications systems, it is imperative to understand the 1668 various impacts of these new components under a variety of attack 1669 situations on the power grid. Consequences of a cyber attack on the 1670 grid telecommunications network can be catastrophic. This is why 1671 security for smart grid is not just an ad hoc feature or product, 1672 it's a complete framework integrating both physical and Cyber 1673 security requirements and covering the entire smart grid networks 1674 from generation to distribution. Security has therefore become one 1675 of the main foundations of the utility telecom network architecture 1676 and must be considered at every layer with a defense-in-depth 1677 approach. Migrating to IP based protocols is key to address these 1678 challenges for two reasons: 1680 o IP enables a rich set of features and capabilities to enhance the 1681 security posture 1683 o IP is based on open standards, which allows interoperability 1684 between different vendors and products, driving down the costs 1685 associated with implementing security solutions in OT networks. 1687 Securing OT (Operation technology) telecommunications over packet- 1688 switched IP networks follow the same principles that are foundational 1689 for securing the IT infrastructure, i.e., consideration must be given 1690 to enforcing electronic access control for both person-to-machine and 1691 machine-to-machine communications, and providing the appropriate 1692 levels of data privacy, device and platform integrity, and threat 1693 detection and mitigation. 1695 7.4.3. (BAS) Security Considerations (sec 4.2.4) 1697 When BAS field networks were developed it was assumed that the field 1698 networks would always be physically isolated from external networks 1699 and therefore security was not a concern. In today's world many BASs 1700 are managed remotely and are thus connected to shared IP networks and 1701 so security is definitely a concern, yet security features are not 1702 available in the majority of BAS field network deployments . 1704 The management network, being an IP-based network, has the protocols 1705 available to enable network security, but in practice many BAS 1706 systems do not implement even the available security features such as 1707 device authentication or encryption for data in transit. 1709 7.4.4. (6TiSCH) Security Considerations (sec 5.3.3) 1711 On top of the classical requirements for protection of control 1712 signaling, it must be noted that 6TiSCH networks operate on limited 1713 resources that can be depleted rapidly in a DoS attack on the system, 1714 for instance by placing a rogue device in the network, or by 1715 obtaining management control and setting up unexpected additional 1716 paths. 1718 7.4.5. (Cellular radio) Security Considerations (sec 6.1.5) 1720 Establishing time-sensitive streams in the network entails reserving 1721 networking resources for long periods of time. It is important that 1722 these reservation requests be authenticated to prevent malicious 1723 reservation attempts from hostile nodes (or accidental 1724 misconfiguration). This is particularly important in the case where 1725 the reservation requests span administrative domains. Furthermore, 1726 the reservation information itself should be digitally signed to 1727 reduce the risk of a legitimate node pushing a stale or hostile 1728 configuration into another networking node. 1730 Note: This is considered important for the security policy of the 1731 network, but does not affect the core DetNet architecture and design. 1733 7.4.6. (Industrial M2M) Communication Today (sec 7.2) 1735 Industrial network scenarios require advanced security solutions. 1736 Many of the current industrial production networks are physically 1737 separated. Preventing critical flows from be leaked outside a domain 1738 is handled today by filtering policies that are typically enforced in 1739 firewalls. 1741 8. IANA Considerations 1743 This memo includes no requests from IANA. 1745 9. Security Considerations 1747 The security considerations of DetNet networks are presented 1748 throughout this document. 1750 10. Informative References 1752 [ARINC664P7] 1753 ARINC, "ARINC 664 Aircraft Data Network, Part 7, Avionics 1754 Full-Duplex Switched Ethernet Network", 2009. 1756 [I-D.ietf-detnet-architecture] 1757 Finn, N., Thubert, P., Varga, B., and J. Farkas, 1758 "Deterministic Networking Architecture", draft-ietf- 1759 detnet-architecture-08 (work in progress), September 2018. 1761 [I-D.ietf-detnet-use-cases] 1762 Grossman, E., "Deterministic Networking Use Cases", draft- 1763 ietf-detnet-use-cases-18 (work in progress), September 1764 2018. 1766 [I-D.varga-detnet-service-model] 1767 Varga, B. and J. Farkas, "DetNet Service Model", draft- 1768 varga-detnet-service-model-02 (work in progress), May 1769 2017. 1771 [IEEE1588] 1772 IEEE, "IEEE 1588 Standard for a Precision Clock 1773 Synchronization Protocol for Networked Measurement and 1774 Control Systems Version 2", 2008. 1776 [MIRAI] krebsonsecurity.com, "https://krebsonsecurity.com/2016/10/ 1777 hacked-cameras-dvrs-powered-todays-massive-internet- 1778 outage/", 2016. 1780 [RFC3552] Rescorla, E. and B. Korver, "Guidelines for Writing RFC 1781 Text on Security Considerations", BCP 72, RFC 3552, 1782 DOI 10.17487/RFC3552, July 2003, 1783 . 1785 [RFC7384] Mizrahi, T., "Security Requirements of Time Protocols in 1786 Packet Switched Networks", RFC 7384, DOI 10.17487/RFC7384, 1787 October 2014, . 1789 Authors' Addresses 1791 Tal Mizrahi 1792 Huawei Network.IO Innovation Lab 1794 Email: tal.mizrahi.phd@gmail.com 1796 Ethan Grossman (editor) 1797 Dolby Laboratories, Inc. 1798 1275 Market Street 1799 San Francisco, CA 94103 1800 USA 1802 Phone: +1 415 645 4726 1803 Email: ethan.grossman@dolby.com 1804 URI: http://www.dolby.com 1806 Andrew J. Hacker 1807 MistIQ Technologies, Inc 1808 Harrisburg, PA 1809 USA 1811 Email: ajhacker@mistiqtech.com 1812 URI: http://www.mistiqtech.com 1814 Subir Das 1815 Applied Communication Sciences 1816 150 Mount Airy Road, Basking Ridge 1817 New Jersey, 07920 1818 USA 1820 Email: sdas@appcomsci.com 1822 John Dowdell 1823 Airbus Defence and Space 1824 Celtic Springs 1825 Newport NP10 8FZ 1826 United Kingdom 1828 Email: john.dowdell.ietf@gmail.com 1829 Henrik Austad 1830 Cisco Systems 1831 Philip Pedersens vei 1 1832 Lysaker 1366 1833 Norway 1835 Email: henrik@austad.us 1837 Kevin Stanton 1838 Intel 1840 Email: kevin.b.stanton@intel.com 1842 Norman Finn 1843 Huawei 1845 Email: norman.finn@mail01.huawei.com