< draft-songlee-aes-cmac-96-02.txt   draft-songlee-aes-cmac-96-03.txt >
JunHyuk Song JunHyuk Song
Radha Poovendran
University of Washington
Jicheol Lee Jicheol Lee
INTERNET DRAFT Samsung Electronics INTERNET DRAFT Samsung Electronics
Expires: November 30, 2005 May 31 2005 Expires: May 30, 2006 November 30 2005
The AES-CMAC-96 Algorithm and its use with IPsec The AES-CMAC-96 Algorithm and its use with IPsec
draft-songlee-aes-cmac-96-02.txt draft-songlee-aes-cmac-96-03.txt
Status of This Memo Status of This Memo
By submitting this Internet-Draft, each author represents that any By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
skipping to change at page 3, line ? skipping to change at page 2, line 8
One-Key CBC-MAC1 (OMAC1) algorithm submitted by Iwata and Kurosawa. One-Key CBC-MAC1 (OMAC1) algorithm submitted by Iwata and Kurosawa.
OMAC1 efficiently reduces the key size of Extended Cipher Block OMAC1 efficiently reduces the key size of Extended Cipher Block
Chaining mode (XCBC). This memo specifies the use of CMAC mode on Chaining mode (XCBC). This memo specifies the use of CMAC mode on
authentication mechanism of IPsec Encapsulating Security Payload authentication mechanism of IPsec Encapsulating Security Payload
(ESP) and the Authentication Header (AH) protocols. This new (ESP) and the Authentication Header (AH) protocols. This new
algorithm is named AES-CMAC-96. algorithm is named AES-CMAC-96.
1. Introduction 1. Introduction
National Institute of Standards and Technology (NIST) has newly National Institute of Standards and Technology (NIST) has newly
specified the Cipher based MAC (CMAC). CMAC [NIST-CMAC] is a keyed specified the Cipher-based Message Authentication Code (CMAC).
hashed function that is based on a symmetric key block cipher such CMAC [NIST-CMAC] is a keyed hash function that is based on a
as Advanced Encryption Standard [AES]. CMAC is equivalent to the symmetric key block cipher such as the Advanced Encryption
One-Key CBC-MAC1 (OMAC1) algorithm submitted by Iwata and Kurosawa Standard [NIST-AES]. CMAC is equivalent to the One-Key CBC MAC1
[OMAC1]. Although the OMAC1 algorithm is based on the eXtended Cipher (OMAC1) submitted by Iwata and Kurosawa [OMAC1a, OMAC1b]. OMAC1
Block Chaining mode (XCBC) algorithm submitted by Rogaway and Black is an improvement of the eXtended Cipher Block Chaining mode (XCBC)
[XCBC], OMAC1 efficiently reduces the key size of XCBC. submitted by Black and Rogaway [XCBCa, XCBCb], which itself is an
This memo specifies the usage of CMAC on authentication mechanism improvement of the basic CBC-MAC. XCBC efficiently addresses the
of IPsec Encapsulating Security Payload (ESP) and the Authentication security deficiencies of CBC-MAC, and OMAC1 efficiently reduces the
Header (AH) protocols. This new algorithm is named AES-CMAC-96. key size of XCBC.
For further information on AH and ESP, refer to [AH] and [ROADMAP].
2. Specification of Language
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [3].
In addition, the following words are used to signify the requirements This memo specifies the usage of CMAC on authentication mechanism
of the specification. of IPsec Encapsulating Security Payload (ESP) [ESP] and the
Authentication Header (AH) protocols. This new algorithm is named
AES-CMAC-96. For further information on AH and ESP, refer to [AH]
and [ROADMAP].
3. Basic definitions 2. Basic definitions
CBC Cipher Block Chaining mode of operation for message CBC Cipher Block Chaining mode of operation for message
authentication code. authentication code.
MAC Message Authentication Code. MAC Message Authentication Code.
A bitstring of a fixed length, computed by MAC A bit string of a fixed length, computed by MAC
generation algorithm, that is used to established generation algorithm, that is used to established
the authority and hence, the integrity of a message. the authority and hence, the integrity of a message.
CMAC Cipher-based MAC based on an approved symmetric key CMAC Cipher-based MAC based on an approved symmetric key
block cipher, such as the Advanced Encryption block cipher, such as the Advanced Encryption
Standard. Standard.
Key (K) 128-bits (16bytes) long key for AES-128 cipher block. Key (K) 128-bits (16bytes) long key for AES-128 cipher block.
Denoted by K. Denoted by K.
Message (M) Message to be authenticated. Message (M) Message to be authenticated.
Denoted by M. Denoted by M.
Length (len) The length of message M in bytes. Length (len) The length of message M in bytes.
Denoted by len. Denoted by len.
Minimum value of the length can be 0. The maximum Minimum value of the length can be 0. The maximum
value of the length is not specified in this document. value of the length is not specified in this document.
truncate(T,l) Truncate T (MAC) in msb-first order with l bytes. truncate(T,l) Truncate T (MAC) in msb-first order with l bytes.
T The output of AES-CMAC-128. T The output of AES-CMAC
Truncated T The truncated output of AES-CMAC-128 in MSB first Truncated T The truncated output of AES-CMAC-128 in MSB first
order. order.
AES-CMAC CMAC generation function based on AES block cipher AES-CMAC CMAC generation function based on AES block cipher
with 128-bits key with 128-bits key
AES-CMAC-96 IPsec AH and ESP MAC generation function based on AES-CMAC-96 IPsec AH and ESP MAC generation function based on
CMAC-AES-128 which truncates MSB 96 bits of 128 bits AES-CMAC which truncates MSB 96 bits of 128 bits
output output
4. AES-CMAC-96 3. AES-CMAC
The underlying algorithm for AES-CMAC-96 are Advanced Encryption The core of AES-CMAC-96 is the AES-CMAC [AES-CMAC]. The underlying
Standard cipher block [AES] and recently defined CMAC mode of algorithm for AES-CMAC are Advanced Encryption Standard cipher block
operation [NIST-CMAC]. The output of AES-CMAC can validate the [AES] and recently defined CMAC mode of operation [NIST-CMAC].
input message. Validating the message provide assurance of the AES-CMAC provides stronger assurance of data integrity than a
integrity and authenticity over the message from the source. checksum or an error detecting code. The verification of a checksum
According to [NIST-CMAC] at least 64-bits should be used for or an error detecting code detects only accidental modifications of
against guessing attack. the data, while CMAC is designed to detect intentional, unauthorized
modifications of the data, as well as accidental modifications. The
output of AES-CMAC can validate the input message. Validating the
message provide assurance of the integrity and authenticity over the
message from the source. According to [NIST-CMAC] at least 64-bits
should be used for against guessing attack. AES-CMAC achieves the
similar security goal of HMAC [RFC-HMAC]. Since AES-CMAC is based
on a symmetric key block cipher, AES, while HMAC is based on a hash
function, such as SHA-1, AES-CMAC is appropriate for information
systems in which AES is more readily available than a hash function.
For detail information about AES-CMAC is available in [AES-CMAC] and
[NIST-CMAC].
For use in IPsec message authentication on AH and ESP, AES-CMAC-96 4. AES-CMAC-96
should be used. AES-CMAC-96 is a AES-CMAC with 96-bit-long truncated
output in most significant bit first order. The output of 96 bits
MAC that will meet the default authenticator length as specified
in [AH]. The result of truncation should be taken in most
significant bits first order. For further information on
AES-CMAC, refer to [AES-CMAC] and [NIST-CMAC].
Figure 1 describes AES-CMAC-96 algorithm: For use in IPsec message authentication on AH and ESP, AES-CMAC-96
should be used. AES-CMAC-96 is a AES-CMAC with 96-bit-long truncated
output in most significant bit first order. The output of 96 bits
MAC that will meet the default authenticator length as specified
in [AH]. The result of truncation should be taken in most
significant bits first order. For further information on AES-CMAC,
refer to [AES-CMAC] and [NIST-CMAC].
In step 1, AES-CMAC is applied to the message 'M' in length 'len' Figure 1 describes AES-CMAC-96 algorithm:
with key 'K'
In step 2, Truncate output block, T with 12 byte in msb-first-order In step 1, AES-CMAC is applied to the message 'M' in length 'len'
and return TT. with key 'K'
In step 2, Truncate output block, T with 12 byte in msb-first-order
and return TT.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ Algorithm AES-CMAC-96 + + Algorithm AES-CMAC-96 +
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ + + +
+ Input : K (128-bit Key described in section 4.1) + + Input : K (128-bit Key described in section 4.1) +
+ : M ( message to be authenticated ) + + : M ( message to be authenticated ) +
+ : len ( length of message in bytes ) + + : len ( length of message in bytes ) +
+ Output : Truncated T (Truncated output with length 12 bytes) + + Output : Truncated T (Truncated output with length 12 bytes) +
+ + + +
skipping to change at page 5, line 34 skipping to change at page 4, line 34
These test cases same as defined in [NIST-CMAC] with one exception of These test cases same as defined in [NIST-CMAC] with one exception of
96 bits truncation 96 bits truncation
-------------------------------------------------- --------------------------------------------------
K 2b7e1516 28aed2a6 abf71588 09cf4f3c K 2b7e1516 28aed2a6 abf71588 09cf4f3c
Subkey Generation Subkey Generation
AES_128(key,0) 7df76b0c 1ab899b3 3e42f047 b91b546f AES_128(key,0) 7df76b0c 1ab899b3 3e42f047 b91b546f
K1 fbeed618 35713366 7c85e08f 7236a8de K1 fbeed618 35713366 7c85e08f 7236a8de
K2 f7ddac30 6ae266cc f90bc11e e46d513b K2 f7ddac30 6ae266cc f90bc11e e46d513b
Example 1: len = 0 Test Case 1: len = 0
M <empty string> M <empty string>
AES_CMAC_96 bb1d6929 e9593728 7fa37d12 AES_CMAC_96 bb1d6929 e9593728 7fa37d12
Example 2: len = 16 Test Case 2: len = 16
M 6bc1bee2 2e409f96 e93d7e11 7393172a M 6bc1bee2 2e409f96 e93d7e11 7393172a
AES_CMAC_96 070a16b4 6b4d4144 f79bdd9d AES_CMAC_96 070a16b4 6b4d4144 f79bdd9d
Example 3: len = 40 Test Case 3: len = 40
M 6bc1bee2 2e409f96 e93d7e11 7393172a M 6bc1bee2 2e409f96 e93d7e11 7393172a
ae2d8a57 1e03ac9c 9eb76fac 45af8e51 ae2d8a57 1e03ac9c 9eb76fac 45af8e51
30c81c46 a35ce411 30c81c46 a35ce411
AES_CMAC_96 dfa66747 de9ae630 30ca3261 AES_CMAC_96 dfa66747 de9ae630 30ca3261
Example 4: len = 64 Test Case 4: len = 64
M 6bc1bee2 2e409f96 e93d7e11 7393172a M 6bc1bee2 2e409f96 e93d7e11 7393172a
ae2d8a57 1e03ac9c 9eb76fac 45af8e51 ae2d8a57 1e03ac9c 9eb76fac 45af8e51
30c81c46 a35ce411 e5fbc119 1a0a52ef 30c81c46 a35ce411 e5fbc119 1a0a52ef
f69f2445 df4f9b17 ad2b417b e66c3710 f69f2445 df4f9b17 ad2b417b e66c3710
AES_CMAC_96 51f0bebf 7e3b9d92 fc497417 AES_CMAC_96 51f0bebf 7e3b9d92 fc497417
-------------------------------------------------- --------------------------------------------------
6. Interaction with the ESP Cipher Mechanism 6. Interaction with the ESP Cipher Mechanism
As of this writing, there are no known issues which preclude the use As of this writing, there are no known issues which preclude the use
of AES-CMAC-96 with any specific cipher algorithm. of AES-CMAC-96 with any specific cipher algorithm.
7. Security Considerations 7. Security Considerations
The security provided by AES-CMAC-96 is based upon the strength of See security consideration of [AES-CMAC].
AES. At the time of this writing there are no practical
cryptographic attacks against AES or AES-CMAC-96.
As is true with any cryptographic algorithm, part of its strength
lies in the correctness of the algorithm implementation, the security
of the key management mechanism and its implementation, the strength
of the associated secret key, and upon the correctness of the
implementation in all of the participating systems. This document
contains test vectors to assist in verifying the correctness of
AES-CMAC-96 code.
8. IANA Consideration 8. IANA Consideration
TBD IANA should allocate a value for IKEv2 Transform Type 3 (Integrity
Algorithm) to the AES-CMAC-PRF-128 algorithm when this document is
published.
9. Acknowledgement 9. Acknowledgement
Portions of this text were borrowed from [NIST-CMAC] and Portions of this text were borrowed from [NIST-CMAC] and [AES-XCBC-MAC].
[AES-XCBC-MAC]. We would like to thank to OMAC1 author Tetsu Iwata We would like to thank to Russ Housley for his useful comments.
and Kaoru Kurosawa, and CMAC author Morris Dworkin.
10. References 10. References
10.1. Normative References
[NIST-CMAC] NIST, Special Publication 800-38B Draft,"Recommendation [NIST-CMAC] NIST, Special Publication 800-38B Draft,"Recommendation
for Block Cipher Modes of Operation: The CMAC Method for Block Cipher Modes of Operation: The CMAC Method
for Authentication," March 9, 2005 for Authentication," March 9, 2005
[AES] NIST, FIPS 197, "Advanced Encryption Standard (AES)," [NIST-AES] NIST, FIPS 197, "Advanced Encryption Standard (AES),"
November 2001. November 2001.
http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf
[OMAC1] "OMAC: One-Key CBC MAC," Tetsu Iwata and Kaoru Kurosawa, [OMAC1] "OMAC: One-Key CBC MAC," Tetsu Iwata and Kaoru Kurosawa,
Department of Computer and Information Sciences, Department of Computer and Information Sciences,
Ilbaraki University, March 10, 2003. Ilbaraki University, March 10, 2003.
[ESP] Kent, S. and R. Atkinson, "IP Encapsulating Security
[AH] Kent, S. and R. Atkinson, "IP Authentication Header", Payload (ESP)", RFC 2406, November 1998.
RFC 2402, November 1998.
[ROADMAP] Thayer, R., N. Doraswamy, and R. Glenn, "IP Security
Document Roadmap", RFC 2411, November 1998.
[XCBC] Black, J. and P. Rogaway, "A Suggestion for Handling [XCBC] Black, J. and P. Rogaway, "A Suggestion for Handling
Arbitrary-Length Messages with the CBC MAC," NIST Arbitrary-Length Messages with the CBC MAC," NIST
Second Modes of Operation Workshop, August 2001. Second Modes of Operation Workshop, August 2001.
http://csrc.nist.gov/CryptoToolkit/modes/proposedmodes/ http://csrc.nist.gov/CryptoToolkit/modes/proposedmodes/
xcbc-mac/xcbc-mac-spec.pdf xcbc-mac/xcbc-mac-spec.pdf
[AES-CMAC] JunHyuk Song and Jicheol Lee, "The AES-CMAC Algorithm" [AES-CMAC] JunHyuk Song, Jicheol Lee, Radha Poovendran, Tetsu Iwata
draft-songlee-aes-cmac-00.txt, May 2005 "The AES-CMAC Algorithm" draft-songlee-aes-cmac-02.txt,
October 2005 (Work in progress)
10.2. Informative References
11. Author's Address [AH] Kent, S. and R. Atkinson, "Security Architecture for the
Internet Protocol", RFC 2401, November 1998.
[ROADMAP] Thayer, R., Doraswamy, N. and R. Glenn, "IP Security
Document Roadmap", RFC 2411, November 1998.
[OMAC1a] Tetsu Iwata and Kaoru Kurosawa, "OMAC: One-Key CBC MAC,"
Fast Software Encryption, FSE 2003, LNCS 2887,
pp. 129-153, Springer-Verlag, 2003.
[RFC-HMAC] Hugo Krawczyk, Mihir Bellare and Ran Canetti,
"HMAC: Keyed-Hashing for Message Authentication,"
RFC2104, February 1997.
[OMAC1b] Tetsu Iwata and Kaoru Kurosawa, "OMAC: One-Key CBC MAC,"
Submission to NIST, December 2002.
Available from the NIST modes of operation web site at
http://csrc.nist.gov/CryptoToolkit/modes/proposedmodes/
omac/omac-spec.pdf
[XCBCa] John Black and Phillip Rogaway, "A Suggestion for
Handling Arbitrary-Length Messages with the CBC MAC,"
NIST Second Modes of Operation Workshop, August 2001.
Available from the NIST modes of operation web site at
http://csrc.nist.gov/CryptoToolkit/modes/proposedmodes/
xcbc-mac/xcbc-mac-spec.pdf
[XCBCb] John Black and Phillip Rogaway, "CBC MACs for
Arbitrary-Length Messages: The Three-Key
Constructions," Journal of Cryptology, Vol. 18, No. 2,
pp. 111-132, Springer-Verlag, Spring 2005.
[IKEv2] Kaufman, C., Ed., "Internet Key Exchange (IKEv2)
Protocol", draft-ietf-ipsec-ikev2-17
(work in progress), September 2004.
11. Author's Address
Junhyuk Song Junhyuk Song
University of Washington
Samsung Electronics Samsung Electronics
+82-31-279-3639 (206) 853-5843
santajunman@hanafos.com songlee@ee.washington.edu
junhyuk.song@samsung.com
Jicheol Lee Jicheol Lee
Samsung Electronics Samsung Electronics
+82-31-279-3605 +82-31-279-3605
jicheol.lee@samsung.com jicheol.lee@samsung.com
Radha Poovendran
Network Security Lab (NSL)
Dept. of Electrical Engineering
University of Washington
(206) 221-6512
radha@ee.washington.edu
Intellectual Property Statement Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
 End of changes. 30 change blocks. 
77 lines changed or deleted 122 lines changed or added

This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/