< draft-ietf-6lo-ap-nd-02.txt		draft-ietf-6lo-ap-nd-03.txt >
	6lo B. Sarikaya		6lo B. Sarikaya
	Internet-Draft Huawei USA		Internet-Draft
	Updates: 6775 (if approved) P. Thubert		Updates: 6775 (if approved) P. Thubert
	Intended status: Standards Track Cisco		Intended status: Standards Track Cisco
	Expires: November 25, 2017 M. Sethi		Expires: March 25, 2018 M. Sethi
	Ericsson		Ericsson
	May 24, 2017		September 21, 2017
	Address Protected Neighbor Discovery for Low-power and Lossy Networks		Address Protected Neighbor Discovery for Low-power and Lossy Networks
	draft-ietf-6lo-ap-nd-02		draft-ietf-6lo-ap-nd-03
	Abstract		Abstract
	This document defines an extension to 6LoWPAN Neighbor Discovery, RFC		This document defines an extension to 6LoWPAN Neighbor Discovery RFC
	6775. Nodes supporting this extension compute a cryptographic Owner		6775. Nodes supporting this extension compute a cryptographic Owner
	Unique Interface ID and associate it with one or more of their		Unique Interface ID and associate it with one or more of their
	Registered Addresses. Once an address is registered with a		Registered Addresses. Once an address is registered with a
	Cryptographic ID, only the owner of that ID can modify the anchor		Cryptographic ID, only the owner of that ID can modify the anchor
	state information of the Registered Address, and Source Address		state information of the Registered Address, and Source Address
	Validation can be enforced.		Validation can be enforced.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on November 25, 2017.		This Internet-Draft will expire on March 25, 2018.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2017 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
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	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	skipping to change at page 2, line 25 ¶		skipping to change at page 2, line 25 ¶
	4. New Fields and Options . . . . . . . . . . . . . . . . . . . 5		4. New Fields and Options . . . . . . . . . . . . . . . . . . . 5
	4.1. New Crypto-ID . . . . . . . . . . . . . . . . . . . . . . 5		4.1. New Crypto-ID . . . . . . . . . . . . . . . . . . . . . . 5
	4.2. Updated EARO . . . . . . . . . . . . . . . . . . . . . . 6		4.2. Updated EARO . . . . . . . . . . . . . . . . . . . . . . 6
	4.3. New Crypto-ID Parameters Option . . . . . . . . . . . . . 7		4.3. New Crypto-ID Parameters Option . . . . . . . . . . . . . 7
	5. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 8		5. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 8
	5.1. Protocol Scope . . . . . . . . . . . . . . . . . . . . . 8		5.1. Protocol Scope . . . . . . . . . . . . . . . . . . . . . 8
	5.2. Protocol Flows . . . . . . . . . . . . . . . . . . . . . 9		5.2. Protocol Flows . . . . . . . . . . . . . . . . . . . . . 9
	5.3. Multihop Operation . . . . . . . . . . . . . . . . . . . 11		5.3. Multihop Operation . . . . . . . . . . . . . . . . . . . 11
	6. Security Considerations . . . . . . . . . . . . . . . . . . . 12		6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
	7. IANA considerations . . . . . . . . . . . . . . . . . . . . . 13		7. IANA considerations . . . . . . . . . . . . . . . . . . . . . 13
			7.1. Crypto Type Registry . . . . . . . . . . . . . . . . . . 13
	8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13		8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
	9. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 13		9. Change Log . . . . . . . . . . . . . . . . . . . . . . . . . 13
	10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13		10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
	10.1. Normative References . . . . . . . . . . . . . . . . . . 13		10.1. Normative References . . . . . . . . . . . . . . . . . . 14
	10.2. Informative references . . . . . . . . . . . . . . . . . 14		10.2. Informative references . . . . . . . . . . . . . . . . . 14
	Appendix A. Requirements Addressed in this Document . . . . . . 16		Appendix A. Requirements Addressed in this Document . . . . . . 16
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
	1. Introduction		1. Introduction
	Neighbor discovery for IPv6 [RFC4861] and stateless address		"Neighbor Discovery Optimizations for 6LoWPAN networks" [RFC6775]
	autoconfiguration [RFC4862] and their extensions are collectively		(6LoWPAN ND) adapts the classical IPv6 ND protocol [RFC4861][RFC4862]
	referred to as the IPv6 Neighbor Discovery Protocol (IPv6 NDP). In		(IPv6 ND) for operations over a constrained low-power and lossy
	order to enable IPv6 NDP operations over a constrained low-power and		network (LLN). In particular, 6LoWPAN ND introduces a unicast host
	lossy network (LLN), "Neighbor Discovery optimizations for 6LoWPAN		address registration mechanism that contributes to reduce the use of
	networks" [RFC6775] (6LoWPAN ND), reduces the use of multicast in the		multicast messages that are present in the classical IPv6 ND
	original protocol and introduces a unicast host address registration		protocol. 6LoWPAN ND defines a new Address Registration Option (ARO)
	technique. The registration mechanism leverages a new Address		that is carried in the unicast Neighbor Solicitation (NS) and
	Registration Option (ARO) that is carried in the unicast Neighbor		Neighbor Advertisement (NA) messages between the 6LoWPAN Node (6LN)
	Solicitation (NS) and Neighbor Advertisement (NA) messages between		and the 6LoWPAN Router (6LR). Additionally, it also defines the
	the 6LoWPAN Node (6LN) and the 6LoWPAN Router (6LR), as well as the
	Duplicate Address Request (DAR) and Duplicate Address Confirmation		Duplicate Address Request (DAR) and Duplicate Address Confirmation
	(DAC) messages between the 6LR and the 6LoWPAN Border Router (6LBR),		(DAC) messages between the 6LR and the 6LoWPAN Border Router (6LBR).
	which is the central repository of all the registered addresses in		In LLN networks, the 6LBR is the central repository of all the
	its domain.		registered addresses in its domain.
	The registration mechanism in 6LoWPAN ND [RFC6775] was created for		The registration mechanism in 6LoWPAN ND [RFC6775] prevents the use
	the original purpose of Duplicate Address Detection (DAD), whereby		of an address if that address is already present in the subnet (first
	use of an address would be granted as long as the address is not		come first serve). In order to validate address ownership, the
	already present in the subnet (first come first serve). In order to		registration mechanism enables the 6LR and 6LBR to validate claims
	validate address ownership, the registration mechanism enables the		for a registered address with an associated Owner Unique Interface
	6LR and 6LBR to correlate further claims for a registered address		IDentifier (OUID). 6LoWPAN ND specifies that the OUID is derived from
	from the device to which it is granted with a Owner Unique Interface		the MAC address of the device (EUI-64), which can be spoofed.
	IDentifier (OUID). With 6LoWPAN ND, the OUID is derived from the MAC		Therefore, any node connected to the subnet and aware of a
	address of the device (EUI-64), which can be spoofed. Therefore, any		registered-address-to-OUID mapping could effectively fake the OUID,
	node connected to the subnet and aware of a registered-address-to-		steal the address and redirect traffic for that address towards a
	OUID mapping may effectively fake the OUID, steal the address and		different 6LN. The "Update to 6LoWPAN ND"
	attract the traffic for that address towards a different Node. In		[I-D.ietf-6lo-rfc6775-update] defines an Extended ARO (EARO) option
	order to allow a more secured registration mechanism, the "Update to		that allows to transport alternate forms of OUIDs, and is a
	6LoWPAN ND" [I-D.ietf-6lo-rfc6775-update] opens the semantics of the		prerequisite for this specification.
	ARO option and allows to transport alternate forms of OUIDs.
	With this specification, a 6LN generates a cryptographic ID (Crypto-		According to this specification, a 6LN generates a cryptographic ID
	ID) and places it in the OUID field in the registration of one (or		(Crypto-ID) and places it in the OUID field in the registration of
	more) of its addresses with the 6LR(s) that it uses as default		one (or more) of its addresses with the 6LR(s) that the 6LN uses as
	router(s). Proof of ownership of the cryptographic ID (Crypto-ID) is		default router(s). Proof of ownership of the cryptographic ID
	passed with the first registration to a given 6LR, and enforced at		(Crypto-ID) is passed with the first registration to a given 6LR, and
	the 6LR, in a new Crypto-ID Parameters Option (CIPO). The 6LR		enforced at the 6LR, in a new Crypto-ID Parameters Option (CIPO).
	validates ownership of the cryptographic ID upon the creation of a		The 6LR validates ownership of the cryptographic ID upon the creation
	registration state, or a change in the anchor information, such as		of a registration state, or a change in the anchor information, such
	Link-Layer Address and associated Layer-2 cryptographic material.		as Link-Layer Address and associated Layer-2 cryptographic material.
	The protected address registration protocol proposed in this document		The protected address registration protocol proposed in this document
	enables the enforcement of Source Address Validation (SAVI)		enables the enforcement of Source Address Validation (SAVI)
	[RFC7039], which ensures that only the correct owner uses a		[RFC7039], which ensures that only the correct owner uses a
	registered address in the source address field in IPv6 packets. With		registered address in the source address field in IPv6 packets.
	this specification, a 6LN that sources a packet has to use a 6LR to		Consequently, a 6LN that sources a packet has to use a 6LR to which
	which the source address of the packet is registered to forward the		the source address of the packet is registered to forward the packet.
	packet. The 6LR maintains state information for the registered		The 6LR maintains state information for the registered addressed,
	addressed along with the MAC address, and link-layer cryptographic		including the MAC address, and a link-layer cryptographic key
	key associated with that node. In SAVI-enforcement mode, the 6LR		associated with the 6LN. In SAVI-enforcement mode, the 6LR allows
	allows only packets from a connected Host if the connected Host owns		only packets from a connected Host if the connected Host owns the
	the registration of the source address of the packet.		registration of the source address of the packet.
	The 6lo adaptation layer framework ([RFC4944], [RFC6282]) expects		The 6lo adaptation layer framework ([RFC4944], [RFC6282]) expects
	that a device forms its IPv6 addresses based on Layer-2 address, so		that a device forms its IPv6 addresses based on Layer-2 address, so
	as to enable a better compression. This is incompatible with "Secure		as to enable a better compression. This is incompatible with "Secure
	Neighbor Discovery (SEND)" [RFC3971] and "Cryptographically Generated		Neighbor Discovery (SEND)" [RFC3971] and "Cryptographically Generated
	Addresses (CGAs)" [RFC3972], which derive the Interface ID (IID) in		Addresses (CGAs)" [RFC3972], which derive the Interface ID (IID) in
	the IPv6 addresses from cryptographic material. "Privacy		the IPv6 addresses from cryptographic material. "Privacy
	Considerations for IPv6 Address Generation Mechanisms"		Considerations for IPv6 Address Generation Mechanisms" [RFC7721]
	[I-D.ietf-6man-ipv6-address-generation-privacy] places additional		places additional recommendations on the way addresses should be
	recommendations on the way addresses should be formed and renewed.		formed and renewed.
	This specification allows a device to form and register addresses at		This document specifies that a device may form and register addresses
	will, without a constraint on the way the address is formed or the		at will, without a constraint on the way the address is formed or the
	number of addresses that are registered in parallel. It enables to		number of addresses that are registered in parallel. It enables to
	protect multiple addresses with a single cryptographic material and		protect multiple addresses with a single cryptographic material and
	to send the proof only once to a given 6LR for multiple addresses and		to send the proof only once to a given 6LR for multiple addresses and
	refresher registrations.		refresher registrations.
	2. Terminology		2. Terminology
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in [RFC2119].		document are to be interpreted as described in [RFC2119].
	Readers are expected to be familiar with all the terms and concepts		Readers are expected to be familiar with all the terms and concepts
	that are discussed in [RFC3971], [RFC3972], [RFC4861], [RFC4919],		that are discussed in [RFC3971], [RFC3972], [RFC4861], [RFC4919],
	[RFC6775], and [I-D.ietf-6lo-backbone-router] which proposes an		[RFC6775], and [I-D.ietf-6lo-backbone-router] which proposes an
	evolution of [RFC6775] for wider applicability.		evolution of [RFC6775] for wider applicability.
	This document defines Crypto-ID as an identifier of variable size		This document defines Crypto-ID as an identifier of variable size
	which in most cases is 64 bits long. It is generated using		which in most cases is 64 bits long. It is generated using
	cryptographic means explained later in this document.		cryptographic means explained later in this document Section 4.1.
	The document also conforms to the terms and models described in		The document also conforms to the terms and models described in
	[RFC5889] and uses the vocabulary and the concepts defined in		[RFC5889] and uses the vocabulary and the concepts defined in
	[RFC4291] for the IPv6 Architecture.		[RFC4291] for the IPv6 Architecture. Finally, common terminology
			related to Low power And Lossy Networks (LLN) defined in [RFC7102] is
	This document uses [RFC7102] for Terminology in Low power And Lossy		also used.
	Networks.
	3. Updating RFC 6775		3. Updating RFC 6775
	With this specification, a node SHOULD use a cryptographic identifier		This specification defines a cryptographic identifier (Crypto-ID)
	(Crypto-ID) as OUID in its registration; the Crypto-ID is calculated		that can be used as a replacement to the MAC address in the OUID
	as described in Section 4.1. The fact that a OUID is a Crypto-ID is		field of the EARO option; the computation of the Crypto-ID is
	indicated in a new 'C' flag in the NS(ARO) message.		detailed in Section 4.1. A node in possession of the necessary
			cryptographic material SHOULD use Crypto-ID by default as OUID in its
			registration. Whether a OUID is a Crypto-ID is indicated by a new
			"C" flag in the NS(EARO) message.
	This specification also introduces a new option, the CIPO, that is		This specification introduces a new option, the CIPO, that is used to
	used to prove ownership of the Crypto-ID. A node that registers for		prove ownership of the Crypto-ID. A node that registers for the
	the first time to a 6LR SHOULD place a CIPO option to its		first time to a 6LR SHOULD place a CIPO option in its registration.
	registration but is not expected to place the option in the next		However, it is not expected to place the option in the periodic
	periodic refresher registrations for that address, or for the		refresher registrations for that address, or to register other
	registration of other addresses with the same OUID. When a 6LR		addresses with the same OUID. When a 6LR receives a NS(EARO)
	receives a NS(ARO) registration with a new Crypto-ID as a OUID, then		registration with a new Crypto-ID as a OUID, it SHOULD challenge by
	it SHOULD challenge by responding with a NA(ARO) with a status of		responding with a NA(EARO) with a status of "Validation Requested".
	"Proof requested". This whole process MAY be skipped in networks		This process of validation MAY be skipped in networks where there is
	where there is no or ultra low expectations of mobility.		no mobility.
	The challenge will also be triggered in the case of a registration		The challenge MUST also be triggered in the case of a registration
	for which the Source Link-Layer Address is not consistent with a		for which the Source Link-Layer Address is not consistent with a
	state that already exists either at the 6LR or the 6LBR. In the		state that already exists either at the 6LR or the 6LBR. In the
	latter case, the 6LBR returns a status of "Proof requested" in the		latter case, the 6LBR returns a status of "Validation Requested" in
	DAR/DAC exchange, which is echoed by the 6LR in the NA (ARO) back to		the DAR/DAC exchange, which is echoed by the 6LR in the NA (EARO)
	the registering node. This flow should not alter a preexisting state		back to the registering node. This flow should not alter a
	in the 6LR or the 6LBR.		preexisting state in the 6LR or the 6LBR.
	Upon a NA(ARO) with a status of "Proof requested", the registering		Upon receiving a NA(EARO) with a status of "Validation Requested",
	node SHOULD retry its registration with a CIPO option that proves its		the registering node SHOULD retry its registration with a CIPO option
	ownership of the Crypto-ID.		that proves its ownership of the Crypto-ID.
	If the 6LR cannot validate the proof, it responds with a status of		If the 6LR cannot validate the CIPO, it responds with a status of
	"Incorrect Proof". Upon a NA(ARO) with a status of "Incorrect		"Validation Failed". After receiving a NA(EARO) with a status of
	Proof", the registering node SHOULD NOT use this Crypto-ID for		"Validation Failed", the registering node MUST NOT use this Crypto-ID
	registering with that 6LR anymore.		for registering with that 6LR.
	4. New Fields and Options		4. New Fields and Options
	4.1. New Crypto-ID		4.1. New Crypto-ID
	Elliptic Curve Cryptography (ECC) is used in the calculation of the		Elliptic Curve Cryptography (ECC) is used to calculate the Crypto-ID.
	Crypto-ID. The digital signature is constructed by using the 6LN's		Each 6LN using a Crypto-ID for registration MUST have a public/
	private key over its EUI-64 (MAC) address. The signature value is		private key pair. The digital signature is constructed by using the
	computed using the ECDSA signature algorithm and the hash function		6LN's private key over its EUI-64 (MAC) address. The signature value
			is computed using the ECDSA signature algorithm and the hash function
	used is SHA-256 [RFC6234]. Public Key is the most important		used is SHA-256 [RFC6234]. Public Key is the most important
	parameter in CGA Parameters (sent by 6LN in an NS message). ECC		parameter in CGA Parameters (sent by 6LN in an NS message). ECC
	Public Key could be in uncompressed form or in compressed form where		Public Key could be in uncompressed form or in compressed form where
	the first octet of the OCTET STRING is 0x04 and 0x02 or 0x03,		the first octet of the OCTET STRING is 0x04 and 0x02 or 0x03,
	respectively. Point compression can further reduce the key size by		respectively. Point compression can further reduce the key size by
	about 32 octets.		about 32 octets.
	First, the modifier is set to a random or pseudo-random 128-bit		The Crypto-ID is computed as follows:
	value. Next, concatenate from left to right the modifier, 9 zero
	octets and the ECC public key. SHA-256 algorithm is applied on the
	concatenation. The 112 leftmost bits of the hash value is taken.
	Concatenate from left to right the modifier value, the subnet prefix
	and the encoded public key. NIST P-256 is executed on the
	concatenation. The leftmost bits of the result is used as the
	Crypto-ID. With this specification, the last 64 bits are retained,
	but it could be expanded to more bits in the future by increasing the
	size of the OUID field.
	In respecting the cryptographic algorithm agility [RFC7696], Curve		1. the modifier is set to a random or pseudo-random 128-bit value
	25519 [RFC7748] can also be used instead of NIST P-256. This is
	indicated by 6LN by setting the Crypto Type field in the CIPO option		2. the modifier, 9 zero octets and the ECC public key are
	to a value of 1. If 6LBR does not support Curve 25519, it will set		concatenated from left to right.
	Crypto Type field to zero. This means that the default algorithm
	(NIST P-256) will be used.		3. the SHA-256 algorithm is applied on the concatenation
			4. the 112 leftmost bits of the hash value are retained
			5. the modifier value, the subnet prefix and the encoded public key
			are concatenated from left to right
			6. NIST P-256 is executed on the concatenation
			7. the leftmost bits of the result are used as the Crypto-ID.
			With this specification, the last 64 bits are retained, but it could
			be expanded to more bits in the future by increasing the size of the
			OUID field.
			To support cryptographic algorithm agility [RFC7696], Curve25519
			[RFC7748] can also be used instead of NIST P-256. This is indicated
			by 6LN using the Crypto Type field in the CIPO option. The document
			currently only defines two possible values for the Crypto Type field.
			A value of 0 indicates that NIST P-256 is used for the signature
			operation and SHA-256 as the hash algorithm. A value of 1 indicates
			that Curve25519 is used for the signature operation and SHA-256 as
			the hash algorithm. New values for the Crypto Type maybe defined in
			the future for new curves.
	4.2. Updated EARO		4.2. Updated EARO
			This specification updates the EARO option as follows:
	0 1 2 3		0 1 2 3
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1		0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Type | Length | Status | Reserved |		| Type | Length | Status | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Reserved |C|T| TID | Registration Lifetime |		| Reserved |C|T| TID | Registration Lifetime |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| |		| |
	+ Owner Unique ID (EUI-64 or equivalent) +		+ Owner Unique ID (EUI-64 or equivalent) +
	| |		| |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 1: Enhanced Address Registration Option		Figure 1: Enhanced Address Registration Option
	Type:		Type: 33
	33
	Length:
	8-bit unsigned integer. The length of the option (including the
	type and length fields) in units of 8 bytes.
	Status:
	8-bit unsigned integer. Indicates the status of a registration in
	the NA response. MUST be set to 0 in NS messages. This
	specification leverages values introduced in the Update to 6LoWPAN
	ND [I-D.ietf-6lo-rfc6775-update], such as 5: Proof Requested, and
	does not require additional values to be defined.
	Reserved:
	This field is unused. It MUST be initialized to zero by the
	sender and MUST be ignored by the receiver.
	C:		Length: 8-bit unsigned integer. The length of the option
			(including the type and length fields) in units of 8
			bytes.
	This specification introduces a C bit, which is set to indicate		Status: 8-bit unsigned integer. Indicates the status of a
	that the Owner Unique ID field contains a Crypto-ID.		registration in the NA response. MUST be set to 0 in
			NS messages. This specification uses values
			introduced in the update to 6LoWPAN ND
			[I-D.ietf-6lo-rfc6775-update], such as "Validation
			Requested" and "Validation Failed". No additional
			value is defined.
	T and TID:		Reserved: This field is unused. It MUST be initialized to zero
			by the sender and MUST be ignored by the receiver.
	Defined in [I-D.ietf-6lo-rfc6775-update].		C: This "C" flag is set to indicate that the Owner
			Unique ID field contains a Crypto-ID.
	Owner Unique ID:		T and TID: Defined in [I-D.ietf-6lo-rfc6775-update].
	When using this specification, this field contains a Crypto-ID.		Owner Unique ID: When the "C" flag is set, this field contains a
			Crypto-ID.
	4.3. New Crypto-ID Parameters Option		4.3. New Crypto-ID Parameters Option
	This specification introduces a new option, the Crypto-ID Parameters		This specification introduces a new option, the Crypto-ID Parameters
	Option (CIPO), that carries the proof of ownership of a crypto-ID.		Option (CIPO), that carries the proof of ownership of a crypto-ID.
	0 1 2 3		0 1 2 3
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1		0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Type | Length | Pad Length | Crypto Type |		| Type | Length | Pad Length | Crypto Type |
	skipping to change at page 7, line 50 ¶		skipping to change at page 8, line 5 ¶
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| |		| |
	. .		. .
	. Padding .		. Padding .
	. .		. .
	| |		| |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 2: Crypto-ID Parameters Option		Figure 2: Crypto-ID Parameters Option
	Type:		Type: CIPO, to be assigned by IANA.
	CIPO, to be assigned by IANA.
	Length:
	The length of the option in units of 8 octets.
	Pad Length:
	The length of the Padding field.
	Crypto Type:
	The type of cryptographic algorithm used in calculation Crypto-ID.
	Default value of all zeros indicate NIST P-256. A value of 1 is
	assigned for Curve 25519. New values may be defined later.
	Modifier:
	128 bit random value.		Length: The length of the option in units of 8 octets.
	Subnet Prefix:		Pad Length: The length of the Padding field.
	64 bit subnet prefix.		Crypto Type: The type of cryptographic algorithm used in
			calculation Crypto-ID. Default value of all zeros
			indicate NIST P-256. A value of 1 is assigned for
			Curve25519. New values may be defined later.
	Public Key:		Modifier: 128 bit random value.
	ECC public key of 6LN.		Subnet Prefix: 64 bit subnet prefix.
	Padding:		Public Key: ECC public key of 6LN.
	A variable-length field making the option length a multiple of 8,		Padding: A variable-length field making the option length a
	containing as many octets as specified in the Pad Length field.		multiple of 8, containing as many octets as specified
			in the Pad Length field.
	5. Protocol Overview		5. Protocol Overview
	5.1. Protocol Scope		5.1. Protocol Scope
	The scope of the present work is a 6LoWPAN Low Power Lossy Network		The scope of the present work is a 6LoWPAN Low Power Lossy Network
	(LLN), typically a stub network connected to a larger IP network via		(LLN), typically a stub network connected to a larger IP network via
	a Border Router called a 6LBR per [RFC6775].		a Border Router called a 6LBR per [RFC6775].
	The 6LBR maintains a registration state for all devices in the		The 6LBR maintains a registration state for all devices in the
	skipping to change at page 9, line 32 ¶		skipping to change at page 9, line 30 ¶
	This specification expects that the peer-wise layer-2 security is		This specification expects that the peer-wise layer-2 security is
	deployed so that all the packets from a particular host are securely		deployed so that all the packets from a particular host are securely
	identifiable by the 6LR. The 6LR may be multiple hops away from the		identifiable by the 6LR. The 6LR may be multiple hops away from the
	6LBR. Packets are routed between the 6LR and the 6LBR via other		6LBR. Packets are routed between the 6LR and the 6LBR via other
	6LRs. This specification expects that a chain of trust is		6LRs. This specification expects that a chain of trust is
	established so that a packet that was validated by the first 6LR can		established so that a packet that was validated by the first 6LR can
	be safely routed by the next 6LRs to the 6LBR.		be safely routed by the next 6LRs to the 6LBR.
	5.2. Protocol Flows		5.2. Protocol Flows
	The 6TiSCH Architecture [I-D.ietf-6tisch-architecture] suggests to		Figure 4 illustrates a registration flow all the way to a 6LowPAN
	use of RPL [RFC6550] as the routing protocol between the 6LRs and the		Backbone Router (6BBR).
	6LBR. In that model, a registration flow happens as shown in
	Figure 4.
	6LoWPAN Node 6LR 6LBR
	(RPL leaf) (router) (RPL root)
	| | |
	| 6LoWPAN ND | 6LoWPAN ND |
	| | |
	| | |
	| NS(ARO) | |
	|-------------->| |
	| 6LoWPAN ND | DAR |
	| |-------------->|
	| |(then RPL DAO) |
	| | |
	| | DAC |
	| |<--------------|
	| NA(ARO) | |
	|<--------------| |
	| | |
	| | |
	Figure 4: (Re-)Registration Flow
	A new device that joins the network auto-configures an address and		A new device that joins the network auto-configures an address and
	performs an initial registration to an on-link 6LR with an NS message		performs an initial registration to an on-link 6LR with an NS message
	that carries an Address Registration Option (ARO) [RFC6775]. The 6LR		that carries an Address Registration Option (EARO) [RFC6775]. The
	validates the address with the central 6LBR using a DAR/DAC exchange,		6LR validates the address with the central 6LBR using a DAR/DAC
	and the 6LR confirms (or denies) the address ownership with an NA		exchange, and the 6LR confirms (or denies) the address ownership with
	message that also carries an Address Registration Option.		an NA message that also carries an Address Registration Option.
	In a multihop 6LoWPAN, the registration with Crypto-ID is propagated		In a multihop 6LoWPAN, the registration with Crypto-ID is propagated
	to 6LBR as described in Section 5.3. If a chain of trust is present		to 6LBR as described in Section 5.3. If a chain of trust is present
	between the 6LR and the 6LBR, then there is no need to propagate the		between the 6LR and the 6LBR, then there is no need to propagate the
	proof of ownership to the 6LBR. All the 6LBR needs to know is that		proof of ownership to the 6LBR. All the 6LBR needs to know is that
	this particular OUID is randomly generated, so as to enforce that any		this particular OUID is randomly generated, so as to enforce that any
	update via a different 6LR is also random.		update via a different 6LR is also random.
	Local or on-link protocol interactions are shown in Figure 5.		6LN 6LR 6LBR 6BBR
	Crypto-ID and ARO are passed to and stored by the 6LR/6LBR on the		| | | |
	first NS and not sent again in the next NS. The operation starts		| NS(EARO) | | |
	with 6LR sending a Router Advertisement (RA) message to 6LN.		|--------------->| | |
			| | Extended DAR | |
			| |-------------->| |
			| | | |
			| | | proxy NS(EARO) |
			| | |--------------->|
			| | | | NS(DAD)
			| | | | ------>
			| | | |
			| | | | <wait>
			| | | |
			| | | proxy NA(EARO) |
			| | |<---------------|
			| | Extended DAC | |
			| |<--------------| |
			| NA(EARO) | | |
			|<---------------| | |
			| | | |
			Figure 4: (Re-)Registration Flow
			On-link (local) protocol interactions are shown in Figure 5. Crypto-
			ID and ARO are passed to and stored by the 6LR on the first NS and
			not sent again in the next NS. The operation starts with 6LR sending
			a Router Advertisement (RA) message to 6LN.
	The 6LR/6LBR ensures first-come/first-serve by storing the ARO and		The 6LR/6LBR ensures first-come/first-serve by storing the ARO and
	the Crypto-ID correlated to the node being registered. The node is		the Crypto-ID correlated to the node being registered. The node is
	free to claim any address it likes as long as it is the first to make		free to claim any address it likes as long as it is the first to make
	such a claim. After a successful registration, the node becomes the		such a claim. After a successful registration, the node becomes the
	owner of the registered address and the address is bound to the		owner of the registered address and the address is bound to the
	Crypto-ID in the 6LR/6LBR registry. This binding can be verified		Crypto-ID in the 6LR/6LBR registry. This binding can be verified
	later, which prevents other nodes from stealing the address and		later, which prevents other nodes from stealing the address and
	trying to attract traffic for that address or use it as their source		trying to attract traffic for that address or use it as their source
	address.		address.
	A node may uses multiple IPv6 addresses at any time. This condition		A node may use multiple IPv6 addresses at the same time. The node
	may happen for privacy reasons		may use the same Crypto-ID to protect multiple IPv6 addresses. The
	[I-D.ietf-6man-ipv6-address-generation-privacy], or when the node		separation of the address and the Crypto-ID avoids the constrained
	moves at a different place and auto-configures an new address from a		device to compute multiple keys for multiple addresses. The
	different prefix. In those situations, the node may use the same		registration process allows the node to bind all of its addresses to
	Crypto-ID to protect multiple IPv6 addresses. The separation of the		the same Crypto-ID.
	address and the Crypto-ID avoids the constrained device to compute
	multiple keys for multiple addresses. The registration process
	allows the node to tie all of its addresses to the same Crypto-ID and
	have the 6LR/6LBR enforce first-come first-serve after that.
	6LN 6LR		6LN 6LR
	| |		| |
	|<------------------- RA --------------------------|		|<------------------- RA --------------------------|
	| |		| |
	|----------- NS with ARO and Crypto-ID ----------->|		|----------- NS with ARO and Crypto-ID ----------->|
	| |		| |
	|<---------- NA with ARO (status=proof requested) -|		|<---------- NA with ARO (status=proof requested) -|
	| |		| |
	|----------- NS with ARO and Crypto-ID ----------->|		|----------- NS with ARO and Crypto-ID ----------->|
	skipping to change at page 11, line 47 ¶		skipping to change at page 11, line 34 ¶
	| |		| |
	|----------- NS with ARO and Crypto-ID ----------->|		|----------- NS with ARO and Crypto-ID ----------->|
	| |		| |
	| |		| |
	|<---------------- NA with ARO --------------------|		|<---------------- NA with ARO --------------------|
	Figure 5: On-link Protocol Operation		Figure 5: On-link Protocol Operation
	5.3. Multihop Operation		5.3. Multihop Operation
	In multihop 6LoWPAN, 6LBR sends RAs with prefixes downstream and it		In a multihop 6LoWPAN, a 6LBR sends RAs with prefixes downstream and
	is the 6LR that receives and relays them to the nodes. 6LR and 6LBR		the 6LR receives and relays them to the nodes. 6LR and 6LBR
	communicate with the ICMPv6 Duplicate Address Request (DAR) and the		communicate using ICMPv6 Duplicate Address Request (DAR) and
	Duplicate Address Confirmation (DAC) messages. The DAR and DAC use		Duplicate Address Confirmation (DAC) messages. The DAR and DAC use
	the same message format as NS and NA with different ICMPv6 type		the same message format as NS and NA, but have different ICMPv6 type
	values.		values.
	In ND-PAR we extend DAR/DAC messages to carry cryptographically		In ND-PAR we extend DAR/DAC messages to carry cryptographically
	generated OUID. In a multihop 6LoWPAN, the node exchanges the		generated OUID. In a multihop 6LoWPAN, the node exchanges the
	messages shown in Figure 4. The 6LBR must be aware of who owns an		messages shown in Figure 4. The 6LBR must identify who owns an
	address (EUI-64) to defend the first node if there is an attacker on		address (EUI-64) to defend it, if there is an attacker on another
	another 6LR. Because of this the content that the source signs and		6LR. Because of this the content that the source signs and the
	the signature needs to be propagated to the 6LBR in DAR message. For		signature needs to be propagated to the 6LBR in the DAR message. For
	this purpose the DAR message sent by 6LR to 6LBR MUST contain the		this purpose the DAR message sent by 6LR to 6LBR MUST contain the
	CIPO option. DAR message also contains ARO.		CIPO option. The DAR message also contains ARO.
	It is possible that occasionally, a 6LR may miss the node's OUID		Occasionally, a 6LR might miss the node's OUID (that it received in
	(that it received in ARO). 6LR should be able to ask for it again.		ARO). 6LR should be able to ask for it again. This is done by
	This is done by restarting the exchanges shown in Figure 5. The		restarting the exchanges shown in Figure 5. The result enables 6LR
	result enables 6LR to refresh the information that was lost. 6LR MUST		to refresh the information that was lost. The 6LR MUST send DAR
	send DAR message with ARO to 6LBR. 6LBR as a reply forms a DAC		message with ARO to 6LBR. The 6LBR replies with a DAC message with
	message with the information copied from the DAR and the Status field		the information copied from the DAR, and the Status field is set to
	is set to zero. With this exchange, the 6LBR can (re)validate and		zero. With this exchange, the 6LBR can (re)validate and store the
	store the information to make sure that the 6LR is not a fake.		information to make sure that the 6LR is not a fake.
	In some cases 6LBR may use DAC message to signal to 6LR that it		In some cases, the 6LBR may use a DAC message to solicit a Crypto-ID
	expects Crypto-ID from 6LR also asks 6LR to verify the EUI-64 6LR		from a 6LR and also requests 6LR to verify the EUI-64 6LR received
	received from 6LN. This may happen when a 6LN node is compromised		from 6LN. This may happen when a 6LN node is compromised and a fake
	and a fake node is sending the Crypto-ID as if it is the node's EUI-		node is sending the Crypto-ID as if it is the node's EUI-64. Note
	64. Note that the detection in this case can only be done by 6LBR		that the detection in this case can only be done by 6LBR not by 6LR.
	not by 6LR.
	6. Security Considerations		6. Security Considerations
	The observations regarding the threats to the Local Link Network in		The observations regarding the threats to the local network in
	[RFC3971] also apply to this specification.		[RFC3971] also apply to this specification.
	This document inherits threats discussed in 6LoWPAN ND [RFC6775] and		The threats discussed in 6LoWPAN ND [RFC6775] and its update
	its update [I-D.ietf-6lo-rfc6775-update] and addresses the potential		[I-D.ietf-6lo-rfc6775-update] also apply here. Compared with SeND,
	attacks related to address stealing and spoofing within a LLN.		this specification saves about 1Kbyte in every NS/NA message. Also,
	Compared with SeND, this specification saves about 1Kbyte in every		this specification separates the cryptographic identifier from the
	NS/NA message. Also, this specification separates the cryptographic		registered IPv6 address so that a node can have more than one IPv6
	identifier from the registered IPv6 address so that a node can have		address protected by the same cryptographic identifier. SeND forces
	more than one IPv6 address protected by the same cryptographic		the IPv6 address to be cryptographic since it integrates the CGA as
	identifier. SeND forces the IPv6 address to be cryptographic since		the IID in the IPv6 address. This specification frees the device to
	it integrates the CGA as the IID in the IPv6 address. This		form its addresses in any fashion, so as to enable the classical
	specification frees the device to form its addresses in any fashion,		6LoWPAN compression which derives IPv6 addresses from Layer-2
	so as to enable the classical 6LoWPAN compression which derives IPv6		addresses, as well as privacy addresses. The threats discussed in
	addresses from Layer-2 addresses, as well as privacy addresses.		Section 9.2 of [RFC3971] are countered by the protocol described in
			this document as well.
	The threats discussed in Section 9.2 of [RFC3971] are countered by
	the protocol described in this document as well.
	Collisions of Crypto-ID is a possibility that needs to be considered.		Collisions of Owner Unique Interface IDentifier (OUID) (which is the
	The formula for calculating probability of a collision is 1 -		Crypto-ID in this specification) is a possibility that needs to be
	e^{-k^2/(2n)}. If the Crypto-ID is 64-bit long, then the chance of		considered. The formula for calculating the probability of a
	finding a collision is 0.01% when the network contains 66 million		collision is 1 - e^{-k^2/(2n)} where n is the maximum population size
	nodes. It is important to note that the collision is only relevant		(2^64 here, 1.84E19) and K is the actual population (number of
	when this happens within one stub network (6LBR). A collision of ID		nodes). If the Crypto-ID is 64-bit long, then the chance of finding
	in ND-PAR is a rare event. However, when such a collision does		a collision is 0.01% when the network contains 66 million nodes. It
	happen, the protocol operation is not affected, although it opens a		is important to note that the collision is only relevant when this
	window for a node to hijack an address from another. The link-layer		happens within one stub network (6LBR). A collision of Crypto-ID is
	security ensures that the nodes would normally not be aware of a		a rare event. In the case of a collision, an attacker may be able to
	collision on the subnet. If a malicious node is able to gain		claim the registered address of an another legitimate node. However
	knowledge of a collision through other means, the only thing that it		for this to happen, the attacker would also need to know the address
	could do is to steal addresses from the other honest node. This		which was registered by the legitimate node. This registered address
	would be no different from what is already possible in a 6lo network		is however never broadcasted on the network and therefore it provides
	today.		an additional entropy of 64-bits that an attacker must correctly
			guess. To prevent such a scenario, it is RECOMMENDED that nodes
			derive the address being registered independently of the OUID.
	7. IANA considerations		7. IANA considerations
	IANA is requested to assign two new option type values for the CIPO		IANA is requested to assign two new option type values for the CIPO
	under the subregistry "IPv6 Neighbor Discovery Option Formats".		under the subregistry "IPv6 Neighbor Discovery Option Formats".
			7.1. Crypto Type Registry
			The following Crypto Type values are defined in this document:
			+-------------------+-----------------------------------------+
			| Crypto Type value | Algorithms |
			+-------------------+-----------------------------------------+
			| 0 | NIST P-256, SHA-256 [RFC6234] |
			| 1 | Curve25519 [RFC7748], SHA-256 [RFC6234] |
			+-------------------+-----------------------------------------+
			Table 1: Crypto Types
			Assignment of new values for new Crypto Type MUST be done through
			IANA with "Specification Required" and "IESG Approval" as defined in
			[RFC8126].
	8. Acknowledgements		8. Acknowledgements
	We are grateful to Rene Struik and Robert Moskowitz for their		Special thanks to Charlie Perkins for his in-depth review and
	comments that lead to many improvements to this document.		constructive suggestions. We are also grateful to Rene Struik and
			Robert Moskowitz for their comments that lead to many improvements to
			this document.
	9. Change Log		9. Change Log
	o submitted version -00 as a working group draft after adoption, and		o submitted version -00 as a working group draft after adoption, and
	corrected the order of authors		corrected the order of authors
	o submitted version -01 with no changes		o submitted version -01 with no changes
	o submitted version -02 with these changes: Moved Requirements to		o submitted version -02 with these changes: Moved Requirements to
	Appendix A, Section 4.2 moved to Section 3, New section 4 on New		Appendix A, Section 4.2 moved to Section 3, New section 4 on New
	Fields and Options, Section 4 changed to Protocol Overview as		Fields and Options, Section 4 changed to Protocol Overview as
	Section 5 with Protocol Scope and Flows subsections.		Section 5 with Protocol Scope and Flows subsections.
	10. References		o submitted version -03 addressing Charlie Perkins' comments
			10. References
	10.1. Normative References		10.1. Normative References
			[I-D.ietf-6lo-rfc6775-update]
			Thubert, P., Nordmark, E., and S. Chakrabarti, "An Update
			to 6LoWPAN ND", draft-ietf-6lo-rfc6775-update-09 (work in
			progress), September 2017.
	[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate		[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
	Requirement Levels", BCP 14, RFC 2119,		Requirement Levels", BCP 14, RFC 2119,
	DOI 10.17487/RFC2119, March 1997,		DOI 10.17487/RFC2119, March 1997,
	<http://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing		[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
	Architecture", RFC 4291, DOI 10.17487/RFC4291, February		Architecture", RFC 4291, DOI 10.17487/RFC4291, February
	2006, <http://www.rfc-editor.org/info/rfc4291>.		2006, <https://www.rfc-editor.org/info/rfc4291>.
	[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,		[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
	"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,		"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
	DOI 10.17487/RFC4861, September 2007,		DOI 10.17487/RFC4861, September 2007,
	<http://www.rfc-editor.org/info/rfc4861>.		<https://www.rfc-editor.org/info/rfc4861>.
	[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless		[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
	Address Autoconfiguration", RFC 4862,		Address Autoconfiguration", RFC 4862,
	DOI 10.17487/RFC4862, September 2007,		DOI 10.17487/RFC4862, September 2007,
	<http://www.rfc-editor.org/info/rfc4862>.		<https://www.rfc-editor.org/info/rfc4862>.
	[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.		[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
	Bormann, "Neighbor Discovery Optimization for IPv6 over		Bormann, "Neighbor Discovery Optimization for IPv6 over
	Low-Power Wireless Personal Area Networks (6LoWPANs)",		Low-Power Wireless Personal Area Networks (6LoWPANs)",
	RFC 6775, DOI 10.17487/RFC6775, November 2012,		RFC 6775, DOI 10.17487/RFC6775, November 2012,
	<http://www.rfc-editor.org/info/rfc6775>.		<https://www.rfc-editor.org/info/rfc6775>.
	[I-D.ietf-6lo-rfc6775-update]
	Thubert, P., Nordmark, E., and S. Chakrabarti, "An Update
	to 6LoWPAN ND", draft-ietf-6lo-rfc6775-update-05 (work in
	progress), May 2017.
	10.2. Informative references		10.2. Informative references
			[I-D.ietf-6lo-backbone-router]
			Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo-
			backbone-router-04 (work in progress), July 2017.
	[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,		[RFC3971] Arkko, J., Ed., Kempf, J., Zill, B., and P. Nikander,
	"SEcure Neighbor Discovery (SEND)", RFC 3971,		"SEcure Neighbor Discovery (SEND)", RFC 3971,
	DOI 10.17487/RFC3971, March 2005,		DOI 10.17487/RFC3971, March 2005,
	<http://www.rfc-editor.org/info/rfc3971>.		<https://www.rfc-editor.org/info/rfc3971>.
	[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",		[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
	RFC 3972, DOI 10.17487/RFC3972, March 2005,		RFC 3972, DOI 10.17487/RFC3972, March 2005,
	<http://www.rfc-editor.org/info/rfc3972>.		<https://www.rfc-editor.org/info/rfc3972>.
	[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
	"Transmission of IPv6 Packets over IEEE 802.15.4
	Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007,
	<http://www.rfc-editor.org/info/rfc4944>.
	[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
	Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
	DOI 10.17487/RFC6282, September 2011,
	<http://www.rfc-editor.org/info/rfc6282>.
	[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6		[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
	over Low-Power Wireless Personal Area Networks (6LoWPANs):		over Low-Power Wireless Personal Area Networks (6LoWPANs):
	Overview, Assumptions, Problem Statement, and Goals",		Overview, Assumptions, Problem Statement, and Goals",
	RFC 4919, DOI 10.17487/RFC4919, August 2007,		RFC 4919, DOI 10.17487/RFC4919, August 2007,
	<http://www.rfc-editor.org/info/rfc4919>.		<https://www.rfc-editor.org/info/rfc4919>.
			[RFC4944] Montenegro, G., Kushalnagar, N., Hui, J., and D. Culler,
			"Transmission of IPv6 Packets over IEEE 802.15.4
			Networks", RFC 4944, DOI 10.17487/RFC4944, September 2007,
			<https://www.rfc-editor.org/info/rfc4944>.
	[RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing		[RFC5889] Baccelli, E., Ed. and M. Townsley, Ed., "IP Addressing
	Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889,		Model in Ad Hoc Networks", RFC 5889, DOI 10.17487/RFC5889,
	September 2010, <http://www.rfc-editor.org/info/rfc5889>.		September 2010, <https://www.rfc-editor.org/info/rfc5889>.
	[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms		[RFC6234] Eastlake 3rd, D. and T. Hansen, "US Secure Hash Algorithms
	(SHA and SHA-based HMAC and HKDF)", RFC 6234,		(SHA and SHA-based HMAC and HKDF)", RFC 6234,
	DOI 10.17487/RFC6234, May 2011,		DOI 10.17487/RFC6234, May 2011,
	<http://www.rfc-editor.org/info/rfc6234>.		<https://www.rfc-editor.org/info/rfc6234>.
	[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
	Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
	JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
	Low-Power and Lossy Networks", RFC 6550,
	DOI 10.17487/RFC6550, March 2012,
	<http://www.rfc-editor.org/info/rfc6550>.
	[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and		[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
	Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January		Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
	2014, <http://www.rfc-editor.org/info/rfc7102>.		DOI 10.17487/RFC6282, September 2011,
			<https://www.rfc-editor.org/info/rfc6282>.
	[RFC7039] Wu, J., Bi, J., Bagnulo, M., Baker, F., and C. Vogt, Ed.,		[RFC7039] Wu, J., Bi, J., Bagnulo, M., Baker, F., and C. Vogt, Ed.,
	"Source Address Validation Improvement (SAVI) Framework",		"Source Address Validation Improvement (SAVI) Framework",
	RFC 7039, DOI 10.17487/RFC7039, October 2013,		RFC 7039, DOI 10.17487/RFC7039, October 2013,
	<http://www.rfc-editor.org/info/rfc7039>.		<https://www.rfc-editor.org/info/rfc7039>.
			[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
			Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
			2014, <https://www.rfc-editor.org/info/rfc7102>.
	[RFC7217] Gont, F., "A Method for Generating Semantically Opaque		[RFC7217] Gont, F., "A Method for Generating Semantically Opaque
	Interface Identifiers with IPv6 Stateless Address		Interface Identifiers with IPv6 Stateless Address
	Autoconfiguration (SLAAC)", RFC 7217,		Autoconfiguration (SLAAC)", RFC 7217,
	DOI 10.17487/RFC7217, April 2014,		DOI 10.17487/RFC7217, April 2014,
	<http://www.rfc-editor.org/info/rfc7217>.		<https://www.rfc-editor.org/info/rfc7217>.
	[RFC7696] Housley, R., "Guidelines for Cryptographic Algorithm		[RFC7696] Housley, R., "Guidelines for Cryptographic Algorithm
	Agility and Selecting Mandatory-to-Implement Algorithms",		Agility and Selecting Mandatory-to-Implement Algorithms",
	BCP 201, RFC 7696, DOI 10.17487/RFC7696, November 2015,		BCP 201, RFC 7696, DOI 10.17487/RFC7696, November 2015,
	<http://www.rfc-editor.org/info/rfc7696>.		<https://www.rfc-editor.org/info/rfc7696>.
			[RFC7721] Cooper, A., Gont, F., and D. Thaler, "Security and Privacy
			Considerations for IPv6 Address Generation Mechanisms",
			RFC 7721, DOI 10.17487/RFC7721, March 2016,
			<https://www.rfc-editor.org/info/rfc7721>.
	[RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves		[RFC7748] Langley, A., Hamburg, M., and S. Turner, "Elliptic Curves
	for Security", RFC 7748, DOI 10.17487/RFC7748, January		for Security", RFC 7748, DOI 10.17487/RFC7748, January
	2016, <http://www.rfc-editor.org/info/rfc7748>.		2016, <https://www.rfc-editor.org/info/rfc7748>.
	[I-D.ietf-6lo-backbone-router]
	Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo-
	backbone-router-03 (work in progress), January 2017.
	[I-D.ietf-6tisch-architecture]
	Thubert, P., "An Architecture for IPv6 over the TSCH mode
	of IEEE 802.15.4", draft-ietf-6tisch-architecture-11 (work
	in progress), January 2017.
	[I-D.ietf-6man-ipv6-address-generation-privacy]		[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
	Cooper, A., Gont, F., and D. Thaler, "Privacy		Writing an IANA Considerations Section in RFCs", BCP 26,
	Considerations for IPv6 Address Generation Mechanisms",		RFC 8126, DOI 10.17487/RFC8126, June 2017,
	draft-ietf-6man-ipv6-address-generation-privacy-08 (work		<https://www.rfc-editor.org/info/rfc8126>.
	in progress), September 2015.
	Appendix A. Requirements Addressed in this Document		Appendix A. Requirements Addressed in this Document
	In this section we state requirements of a secure neighbor discovery		In this section we state requirements of a secure neighbor discovery
	protocol for low-power and lossy networks.		protocol for low-power and lossy networks.
	o The protocol MUST be based on the Neighbor Discovery Optimization		o The protocol MUST be based on the Neighbor Discovery Optimization
	for Low-power and Lossy Networks protocol defined in [RFC6775].		for Low-power and Lossy Networks protocol defined in [RFC6775].
	RFC6775 utilizes optimizations such as host-initiated interactions		RFC6775 utilizes optimizations such as host-initiated interactions
	for sleeping resource-constrained hosts and elimination of		for sleeping resource-constrained hosts and elimination of
	skipping to change at page 17, line 12 ¶		skipping to change at page 17, line 8 ¶
	be extended to carry the relevant forms of Unique Interface		be extended to carry the relevant forms of Unique Interface
	IDentifier.		IDentifier.
	o The Neighbour Discovery should specify the formation of a site-		o The Neighbour Discovery should specify the formation of a site-
	local address that follows the security recommendations from		local address that follows the security recommendations from
	[RFC7217].		[RFC7217].
	Authors' Addresses		Authors' Addresses
	Behcet Sarikaya		Behcet Sarikaya
	Huawei USA		Plano, TX
	5340 Legacy Dr. Building 3		USA
	Plano, TX 75024
	Email: sarikaya@ieee.org		Email: sarikaya@ieee.org
	Pascal Thubert		Pascal Thubert
	Cisco Systems, Inc		Cisco Systems, Inc
	Building D		Building D
	45 Allee des Ormes - BP1200		45 Allee des Ormes - BP1200
	MOUGINS - Sophia Antipolis 06254		MOUGINS - Sophia Antipolis 06254
	FRANCE		FRANCE
End of changes. 80 change blocks.
	322 lines changed or deleted		322 lines changed or added
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