TCPM Working Group R. Bonica Internet-Draft T. Li Intended status: Standards Track P. Chen Expires: 4 May 2027 P. Kumar HPE R. Thomas Arista Networks A. Sujeet Nayak A. Banerjee Cisco Systems 31 October 2026 Cryptographic Algorithms That Produce 256-bit MACs For Use With TCP-AO draft-bonica-tcpm-tcp-ao-long-algs-07 Abstract RFC5926 creates a registry of cryptographic algorithms that can be used with TCP-AO. This document expands that registry, adding two Message Authentication Code (MAC) algorithms, HMAC-SHA256 and KMAC256. The MAC algorithms described by this document produce 256-bit (i.e., 32-byte) MACs. When 32-byte MACs are encoded in TCP-AO, the TCP-AO consumes 36 of the 40 bytes available for TCP options. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 4 May 2027. Copyright Notice Copyright (c) 2026 IETF Trust and the persons identified as the document authors. All rights reserved. Bonica, et al. Expires 4 May 2027 [Page 1] Internet-Draft tcp-ao-algs October 2026 This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Requirements Language . . . . . . . . . . . . . . . . . . . . 3 3. Algorithm Classes . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Key Derivation Functions (KDFs) . . . . . . . . . . . . . 3 3.2. MAC Algorithms . . . . . . . . . . . . . . . . . . . . . 3 3.2.1. The Use of HMAC-SHA256 . . . . . . . . . . . . . . . 4 3.2.2. The Use of KMAC256 . . . . . . . . . . . . . . . . . 4 4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 7. Normative References . . . . . . . . . . . . . . . . . . . . 6 Appendix A. Test Vectors . . . . . . . . . . . . . . . . . . . . 7 A.1. Intermediate Values . . . . . . . . . . . . . . . . . . . 8 A.1.1. HMAC-SHA256 . . . . . . . . . . . . . . . . . . . . . 8 A.1.2. KMAC256 . . . . . . . . . . . . . . . . . . . . . . . 9 A.2. IPv4 HMAC-SHA256 Output Test Vectors . . . . . . . . . . 10 A.2.1. HMAC-SHA256 (Default - Covers TCP Options) . . . . . 10 A.2.2. HMAC-SHA256 (Omits TCP Options) . . . . . . . . . . . 12 A.3. IPv4 KMAC256 Output Test Vectors . . . . . . . . . . . . 14 A.3.1. KMAC256 (Default - Covers TCP Options) . . . . . . . 14 A.3.2. KMAC256 (Omits TCP Options) . . . . . . . . . . . . . 16 A.4. IPv6 HMAC-SHA256 Output Test Vectors . . . . . . . . . . 18 A.4.1. HMAC-SHA256 (Default - Covers TCP Options) . . . . . 18 A.4.2. HMAC-SHA256 (Omits TCP Options) . . . . . . . . . . . 20 A.5. IPv6 KMAC256 Output Test Vectors . . . . . . . . . . . . 22 A.5.1. KMAC256 (Default - Covers TCP Options) . . . . . . . 22 A.5.2. KMAC256 (Omits TCP Options) . . . . . . . . . . . . . 24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 26 1. Introduction [RFC5926] creates a registry of cryptographic algorithms that can be used with TCP-AO [RFC5925]. This document expands that registry, adding two Message Authentication Code (MAC) algorithms, HMAC-SHA256 and KMAC256. Bonica, et al. Expires 4 May 2027 [Page 2] Internet-Draft tcp-ao-algs October 2026 The MAC algorithms described by this document produce 256-bit (i.e., 32-byte) MACs. When 32-byte MACs are encoded in TCP-AO, the TCP-AO consumes 36 of the 40 bytes available for TCP options. 2. Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. 3. Algorithm Classes [RFC5925] requires the following cryptographic algorithm classes: * Key Derivation Functions (KDFs) * MAC Algorithms Section 3.1 of this document addresses KDFs while Section 3.2 addresses MAC algorithms. 3.1. Key Derivation Functions (KDFs) A KDF converts Input Keying Material (IKM) into cryptographically secure Output Keying Material (OKM). HMAC-SHA256 uses HKDF-SHA256 while KMAC256 uses KMAC256-KDF, which is based on the one-step key- derivation function in [DOI.10.6028_NIST.SP.800-56Cr2]. [I-D.ietf-tcpm-tcp-ao-algs] describes both of these. 3.2. MAC Algorithms Each MAC algorithm defined for TCP-AO has the following fixed elements as part of its definition: * KDF_alg is the name of the KDF algorithm used to generate the Traffic_Key. * Key_Length is the length of the Traffic_Key used in this MAC, measured in bits. In this document, the Key_Length is always 256 bits. * MAC_Length is the desired length of the MAC to be produced by the algorithm. In this document, the MAC_Length is always 256 bits. MACs computed for TCP-AO have the following interface: Bonica, et al. Expires 4 May 2027 [Page 3] Internet-Draft tcp-ao-algs October 2026 * MAC = MAC_alg(Traffic_Key, Message) where: * MAC is the value to be encoded in TCP-AO. * MAC_alg is the MAC algorithm used. * Traffic_Key is the result of the KDF. * Message is the message to be authenticated, as specified in Section 5.1 of [RFC5925]. 3.2.1. The Use of HMAC-SHA256 The three fixed elements for HMAC-SHA256 are: * KDF_alg: HKDF-SHA256. * Key_Length: 256 bits. * MAC_Length: 256 bits. In the interface: * MAC = MAC_alg(Traffic_Key, Message) HMAC-SHA256 for TCP-AO has the following values: * MAC is the value to be encoded in TCP-AO. * MAC_alg is HMAC-SHA256. * Traffic_Key is the result of the KDF. * Message is the message to be authenticated, as specified in Section 5.1 of [RFC5925]. 3.2.2. The Use of KMAC256 The three fixed elements for KMAC256 are: * KDF_alg: KMAC256-KDF. * Key_Length: 256 bits. * MAC_Length: 256 bits. Bonica, et al. Expires 4 May 2027 [Page 4] Internet-Draft tcp-ao-algs October 2026 In the interface: * MAC = MAC_alg(Traffic_Key, Message) KMAC256 takes more arguments than the generic two-argument interface above. In the notation of [DOI.10.6028_NIST.SP.800-185], KMAC256 for TCP-AO is: * MAC = KMAC256(K = Traffic_Key, X = Message, L = 256, S = "") KMAC256 for TCP-AO has the following values: * MAC is the value to be encoded in TCP-AO. * MAC_alg is KMAC256. * Traffic_Key is the result of the KDF. * Message is the message to be authenticated, as specified in Section 5.1 of [RFC5925]. * L = 256 (bits) is the requested MAC length. * S is the empty (zero-length) string. 4. Security Considerations This document inherits all of the security considerations of [RFC5869], [RFC5925], [RFC8702],[RFC9688], and [I-D.ietf-tcpm-tcp-ao-algs]. 5. IANA Considerations IANA is requested to add the following entries to the "Cryptographic Algorithms for TCP-AO Registration" (https://www.iana.org/assignments/tcp-parameters/tcp- parameters.xhtml#tcp-parameters-3). +=============+===============+ | Algorithm | Reference | +=============+===============+ | HMAC-SHA256 | This Document | +-------------+---------------+ | KMAC256 | This Document | +-------------+---------------+ Table 1: IANA Actions Bonica, et al. Expires 4 May 2027 [Page 5] Internet-Draft tcp-ao-algs October 2026 6. Acknowledgements Thanks to Eric Biggers, Lars Eggert, Gorry Fairhurst, C.M. Heard, Russ Housley, John Mattsson, Yoshifumi Nishida, Joe Touch, Michael Tuxen, and Magnus Westerlund for their review and comments. 7. Normative References [DOI.10.6028_NIST.SP.800-56Cr2] Barker, E., Chen, L., and R. Davis, "Recommendation for Key-Derivation Methods in Key-Establishment Schemes", National Institute of Standards and Technology, DOI 10.6028/nist.sp.800-56cr2, August 2020, . [DOI.10.6028_NIST.SP.800-185] Kelsey, J., Change, S., and R. Perlner, "SHA-3 derived functions: cSHAKE, KMAC, TupleHash and ParallelHash", National Institute of Standards and Technology, DOI 10.6028/nist.sp.800-185, December 2016, . [I-D.ietf-tcpm-tcp-ao-algs] Bonica, R. P., Li, T., Chen, P., Kumar, P., Thomas, R., Nayak, A. S., and A. Banerjee, "Cryptographic Algorithms That Produce 128-bit MACs For Use With TCP-AO", Work in Progress, Internet-Draft, draft-ietf-tcpm-tcp-ao-algs-09, 30 October 2026, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC5869] Krawczyk, H. and P. Eronen, "HMAC-based Extract-and-Expand Key Derivation Function (HKDF)", RFC 5869, DOI 10.17487/RFC5869, May 2010, . [RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP Authentication Option", RFC 5925, DOI 10.17487/RFC5925, June 2010, . [RFC5926] Lebovitz, G. and E. Rescorla, "Cryptographic Algorithms for the TCP Authentication Option (TCP-AO)", RFC 5926, DOI 10.17487/RFC5926, June 2010, . Bonica, et al. Expires 4 May 2027 [Page 6] Internet-Draft tcp-ao-algs October 2026 [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8702] Kampanakis, P. and Q. Dang, "Use of the SHAKE One-Way Hash Functions in the Cryptographic Message Syntax (CMS)", RFC 8702, DOI 10.17487/RFC8702, January 2020, . [RFC9235] Touch, J. and J. Kuusisaari, "TCP Authentication Option (TCP-AO) Test Vectors", RFC 9235, DOI 10.17487/RFC9235, May 2022, . [RFC9688] Housley, R., "Use of the SHA3 One-Way Hash Functions in the Cryptographic Message Syntax (CMS)", RFC 9688, DOI 10.17487/RFC9688, November 2024, . Appendix A. Test Vectors This appendix provides test vectors to validate the correct implementation of TCP-AO and the cryptographic algorithms defined in this document. The format of these test vectors follows [RFC9235]. In the following sections, all values are shown as space-separated two-digit hexadecimal octets, 16 octets per line, as is typical for data dumps. The IP/TCP data shows the entire IP packet, including the TCP segment, the TCP-AO option, and any other TCP options (whether or not they are covered by TCP-AO, as indicated). In these test vectors, the Master_Key is the following 32-octet string, used directly as an octet string (not as ASCII hex text): Master_Key: 01 23 45 67 89 ab cd ef 01 23 45 67 89 ab cd ef 01 23 45 67 89 ab cd ef 01 23 45 67 89 ab cd ef All vectors are shown from the client's perspective. In the IPv4 vectors, the client is 10.11.12.13 and the server is 172.27.28.29. In the IPv6 vectors, the client is fd00::1 and the server is fd00::2. The client uses an ephemeral port and the server uses port 179. The Sequence Number Extension (SNE) is 0. The TCP-AO option is 36 bytes long (Kind 29, Length 36, KeyID, RNextKeyID, and a 32-byte MAC). Segments sent by the client carry KeyID 61 (0x3d) and RNextKeyID 84 (0x54). Segments sent by the server carry KeyID 84 and RNextKeyID 61. Bonica, et al. Expires 4 May 2027 [Page 7] Internet-Draft tcp-ao-algs October 2026 Because the TCP-AO option is 36 bytes long, only 4 of the 40 bytes available for TCP options remain for other options. The SYN and SYN- ACK segments therefore carry only the MSS option (4 bytes) in addition to TCP-AO, and the non-SYN segments carry no other TCP options. Consequently, in the "Omits TCP Options" vectors, omission affects the MAC input only for the SYN and SYN-ACK segments, where the MSS option is removed. For the "Omits TCP Options" test vectors, the MAC is computed as described in Section 5.1 of [RFC5925]. All TCP options other than TCP-AO are removed from the MAC input. The Data Offset field of the TCP header and the TCP length in the pseudoheader retain the values of the original segment; they are not recomputed to reflect the removed options. The TCP checksum and the MAC field are set to zero. The MAC input therefore consists of the following, in order: * The 4-byte SNE. * The IP pseudoheader, using the TCP length of the original segment. * The 20-byte fixed TCP header, with the original Data Offset and the checksum set to zero. * The TCP-AO option, with the MAC field set to zero. * The TCP payload, if any. The KDF Context contains the source address, destination address, source port, destination port, the sender's ISN, and the receiver's ISN. The receiver's ISN is zero only for a segment with SYN set and ACK clear (the initial SYN). A SYN-ACK carries the client's ISN in its acknowledgment, so its traffic key is derived with both ISNs and is the same as the key for subsequent non-SYN segments in that direction. A.1. Intermediate Values This section shows the intermediate values for the first test vector of each algorithm: the IPv4 Send (Client) SYN that covers TCP options. The Master_Key is the 32-octet string given above. A.1.1. HMAC-SHA256 The Context is the source address, destination address, source port, destination port, sender ISN, and receiver ISN (zero for a SYN), for a total of 20 octets: Bonica, et al. Expires 4 May 2027 [Page 8] Internet-Draft tcp-ao-algs October 2026 Context: 0a 0b 0c 0d ac 1b 1c 1d e9 d7 00 b3 fb fb ab 5a 00 00 00 00 The PRK is HKDF-Extract(salt, Master_Key), where the salt is 32 zero octets: PRK: 62 84 2b 29 23 28 54 21 3a 1d 32 03 c3 71 91 bf ee ad bd 80 ec 84 89 e9 93 4c 44 51 e0 24 ac 7e The traffic key is HKDF-Expand(PRK, Context, 32), which is the Send_SYN_traffic_key shown in the vector. The MAC input is the following 76 octets. The MAC is HMAC-SHA256(Traffic_Key, MAC input): MAC input: 00 00 00 00 0a 0b 0c 0d ac 1b 1c 1d 00 06 00 3c e9 d7 00 b3 fb fb ab 5a 00 00 00 00 f0 02 ff ff 00 00 00 00 02 04 05 b4 1d 24 3d 54 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 A.1.2. KMAC256 The Context is: Context: 0a 0b 0c 0d ac 1b 1c 1d c4 fa 00 b3 78 7a 1d df 00 00 00 00 The traffic key is KMAC256 with a key of 132 zero octets, the following 56 octets as input (counter, Master_Key, and Context), an output length of 256 bits, and the customization string "KDF". It is the Send_SYN_traffic_key shown in the vector: KDF input: 00 00 00 01 01 23 45 67 89 ab cd ef 01 23 45 67 89 ab cd ef 01 23 45 67 89 ab cd ef 01 23 45 67 89 ab cd ef 0a 0b 0c 0d ac 1b 1c 1d c4 fa 00 b3 78 7a 1d df 00 00 00 00 The MAC input is the following 76 octets. The MAC is KMAC256(Traffic_Key, MAC input, 256 bits, ""): Bonica, et al. Expires 4 May 2027 [Page 9] Internet-Draft tcp-ao-algs October 2026 MAC input: 00 00 00 00 0a 0b 0c 0d ac 1b 1c 1d 00 06 00 3c c4 fa 00 b3 78 7a 1d df 00 00 00 00 f0 02 ff ff 00 00 00 00 02 04 05 b4 1d 24 3d 54 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 A.2. IPv4 HMAC-SHA256 Output Test Vectors A.2.1. HMAC-SHA256 (Default - Covers TCP Options) A.2.1.1. Send (Client) SYN (Covers Options) Client ISN = 0xfbfbab5a Send_SYN_traffic_key: eb 5a 40 32 e9 3e 6c 78 02 a7 41 ac 89 9a 63 12 d3 46 a9 dc 1d 2b ed 62 e2 b6 de 94 7f 6c 5c 7d IPv4/TCP: 45 e0 00 50 dd 0f 40 00 ff 06 bf 67 0a 0b 0c 0d ac 1b 1c 1d e9 d7 00 b3 fb fb ab 5a 00 00 00 00 f0 02 ff ff ac f7 00 00 02 04 05 b4 1d 24 3d 54 37 ce 43 46 36 1b fa 5a 1a 2c 5c ed 00 cf 37 e4 35 16 46 03 13 f9 c2 43 07 e5 01 6e 67 be 72 a1 MAC: 37 ce 43 46 36 1b fa 5a 1a 2c 5c ed 00 cf 37 e4 35 16 46 03 13 f9 c2 43 07 e5 01 6e 67 be 72 a1 A.2.1.2. Receive (Server) SYN-ACK (Covers Options) Bonica, et al. Expires 4 May 2027 [Page 10] Internet-Draft tcp-ao-algs October 2026 Server ISN = 0x11c14261 Receive_SYN_traffic_key: d9 9f d0 ae be 69 c9 aa 6c 3d 60 d6 37 c5 6a a9 b7 28 10 93 2a a9 c1 69 f6 a9 80 0f 6a 8c f0 b5 IPv4/TCP: 45 e0 00 50 65 06 40 00 ff 06 37 71 ac 1b 1c 1d 0a 0b 0c 0d 00 b3 e9 d7 11 c1 42 61 fb fb ab 5b f0 12 ff ff 43 a4 00 00 02 04 05 b4 1d 24 54 3d d4 e0 39 44 e4 e3 83 03 e3 b7 73 a2 f4 4e 00 be df fb 55 d4 8f 90 cb 6d 19 ee 4d 18 85 21 4f 2d MAC: d4 e0 39 44 e4 e3 83 03 e3 b7 73 a2 f4 4e 00 be df fb 55 d4 8f 90 cb 6d 19 ee 4d 18 85 21 4f 2d A.2.1.3. Send (Client) Non-SYN (Covers Options) Send_other_traffic_key: 3d a8 19 31 9b 16 cb 05 2b 21 ce 1b 64 d2 5d 8a 62 c4 7e fa 15 8c 7b f2 42 9f 28 8d 6d 58 f6 fb IPv4/TCP: 45 e0 00 8f 36 a1 40 00 ff 06 65 97 0a 0b 0c 0d ac 1b 1c 1d e9 d7 00 b3 fb fb ab 5b 11 c1 42 62 e0 18 01 04 3e a9 00 00 1d 24 3d 54 a7 66 ae 64 6c b8 e9 4e e8 bf 81 b6 4e 38 60 33 f0 d4 7f 49 a7 9d 54 d2 1c 33 63 fb 1c b1 89 c5 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 da bf 00 b4 0a 0b 0c 0d 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 da bf 02 08 40 06 00 64 00 01 01 00 MAC: a7 66 ae 64 6c b8 e9 4e e8 bf 81 b6 4e 38 60 33 f0 d4 7f 49 a7 9d 54 d2 1c 33 63 fb 1c b1 89 c5 A.2.1.4. Receive (Server) Non-SYN (Covers Options) Bonica, et al. Expires 4 May 2027 [Page 11] Internet-Draft tcp-ao-algs October 2026 Receive_other_traffic_key: d9 9f d0 ae be 69 c9 aa 6c 3d 60 d6 37 c5 6a a9 b7 28 10 93 2a a9 c1 69 f6 a9 80 0f 6a 8c f0 b5 IPv4/TCP: 45 e0 00 8f 1f a9 40 00 ff 06 7c 8f ac 1b 1c 1d 0a 0b 0c 0d 00 b3 e9 d7 11 c1 42 62 fb fb ab 9e e0 18 01 00 80 8b 00 00 1d 24 54 3d 1d 00 f2 99 aa b9 17 58 b4 db d6 02 2c 82 e5 3b 9b ca b6 69 41 1c db 0e e3 ab 9d 32 ef 91 fe a3 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 da c0 00 b4 ac 1b 1c 1d 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 da c0 02 08 40 06 00 64 00 01 01 00 MAC: 1d 00 f2 99 aa b9 17 58 b4 db d6 02 2c 82 e5 3b 9b ca b6 69 41 1c db 0e e3 ab 9d 32 ef 91 fe a3 A.2.2. HMAC-SHA256 (Omits TCP Options) A.2.2.1. Send (Client) SYN (Omits Options) Client ISN = 0xcb0efbee Send_SYN_traffic_key: af ea c8 22 53 08 be e3 a0 01 a2 69 6c d2 d3 c6 9b 47 e7 71 e7 f4 4c cd c5 6d 8b bd 74 93 d4 7a IPv4/TCP: 45 e0 00 50 53 99 40 00 ff 06 48 de 0a 0b 0c 0d ac 1b 1c 1d ff 12 00 b3 cb 0e fb ee 00 00 00 00 f0 02 ff ff 87 75 00 00 02 04 05 b4 1d 24 3d 54 03 c9 67 0e 94 d4 2a 3f c6 1d ee 5e a2 5a 3f 6f 52 ea 01 e9 5b 21 89 37 b3 25 ac 51 2b d3 fc 57 MAC: 03 c9 67 0e 94 d4 2a 3f c6 1d ee 5e a2 5a 3f 6f 52 ea 01 e9 5b 21 89 37 b3 25 ac 51 2b d3 fc 57 A.2.2.2. Receive (Server) SYN-ACK (Omits Options) Bonica, et al. Expires 4 May 2027 [Page 12] Internet-Draft tcp-ao-algs October 2026 Server ISN = 0xacd5b5e1 Receive_SYN_traffic_key: 7b 4f d3 74 25 3a 5a 87 5e 86 86 f9 5a 60 69 1c 3b 5a 3f 4e a1 46 8e d6 fc 9c d2 9a 5a 41 56 9f IPv4/TCP: 45 e0 00 50 32 84 40 00 ff 06 69 f3 ac 1b 1c 1d 0a 0b 0c 0d 00 b3 ff 12 ac d5 b5 e1 cb 0e fb ef f0 12 ff ff 61 2d 00 00 02 04 05 b4 1d 24 54 3d ab a7 71 6f 82 b8 94 d8 18 3f a5 ff a8 3a 12 9e c8 b0 72 7d fc 29 03 20 1e 32 96 b7 2d 7f 62 f6 MAC: ab a7 71 6f 82 b8 94 d8 18 3f a5 ff a8 3a 12 9e c8 b0 72 7d fc 29 03 20 1e 32 96 b7 2d 7f 62 f6 A.2.2.3. Send (Client) Non-SYN (Omits Options) Send_other_traffic_key: 2e d5 79 59 d5 45 37 cf 3c a1 73 7d a4 24 0e a6 38 8a d4 c2 b8 e4 c0 eb ca 06 a2 6b 00 93 8b 55 IPv4/TCP: 45 e0 00 8f a8 f5 40 00 ff 06 f3 42 0a 0b 0c 0d ac 1b 1c 1d ff 12 00 b3 cb 0e fb ef ac d5 b5 e2 e0 18 01 04 c9 56 00 00 1d 24 3d 54 20 2c 64 4a 4d 8d 1c 63 84 d2 43 ab 1c f5 c1 4e 19 c8 33 c9 bd b5 18 2d bc 83 35 b4 05 1b d9 d3 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 da bf 00 b4 0a 0b 0c 0d 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 da bf 02 08 40 06 00 64 00 01 01 00 MAC: 20 2c 64 4a 4d 8d 1c 63 84 d2 43 ab 1c f5 c1 4e 19 c8 33 c9 bd b5 18 2d bc 83 35 b4 05 1b d9 d3 A.2.2.4. Receive (Server) Non-SYN (Omits Options) Bonica, et al. Expires 4 May 2027 [Page 13] Internet-Draft tcp-ao-algs October 2026 Receive_other_traffic_key: 7b 4f d3 74 25 3a 5a 87 5e 86 86 f9 5a 60 69 1c 3b 5a 3f 4e a1 46 8e d6 fc 9c d2 9a 5a 41 56 9f IPv4/TCP: 45 e0 00 8f 54 37 40 00 ff 06 48 01 ac 1b 1c 1d 0a 0b 0c 0d 00 b3 ff 12 ac d5 b5 e2 cb 0e fc 32 e0 18 01 00 64 a2 00 00 1d 24 54 3d 22 d6 7d 24 a8 eb cc 54 d2 d5 01 af 1a 4b 8b 35 e4 4b de 32 13 63 b3 57 dd 08 3e 5e 6a 6f 85 dd ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 da c0 00 b4 ac 1b 1c 1d 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 da c0 02 08 40 06 00 64 00 01 01 00 MAC: 22 d6 7d 24 a8 eb cc 54 d2 d5 01 af 1a 4b 8b 35 e4 4b de 32 13 63 b3 57 dd 08 3e 5e 6a 6f 85 dd A.3. IPv4 KMAC256 Output Test Vectors A.3.1. KMAC256 (Default - Covers TCP Options) A.3.1.1. Send (Client) SYN (Covers Options) Client ISN = 0x787a1ddf Send_SYN_traffic_key: 57 8e 81 ab c6 6b b1 02 1d 2c 97 c1 39 85 bf a4 2b 3d e7 91 01 7f 1f 15 8e 17 a9 1d 0d cd 7f 09 IPv4/TCP: 45 e0 00 50 7b 9f 40 00 ff 06 20 d8 0a 0b 0c 0d ac 1b 1c 1d c4 fa 00 b3 78 7a 1d df 00 00 00 00 f0 02 ff ff 03 8d 00 00 02 04 05 b4 1d 24 3d 54 fa ce 54 46 15 1b b9 ab 73 da 1a e7 dc 2b d7 8e d5 18 de ea 73 40 af 89 fc d0 27 94 9e 81 75 98 MAC: fa ce 54 46 15 1b b9 ab 73 da 1a e7 dc 2b d7 8e d5 18 de ea 73 40 af 89 fc d0 27 94 9e 81 75 98 Bonica, et al. Expires 4 May 2027 [Page 14] Internet-Draft tcp-ao-algs October 2026 A.3.1.2. Receive (Server) SYN-ACK (Covers Options) Server ISN = 0xfadd6de9 Receive_SYN_traffic_key: 16 8d 69 c0 a9 14 fe be f9 24 1b 1c d1 de e3 19 86 cc a6 58 68 46 ba e0 f0 9d 9a 7f aa 33 d4 c1 IPv4/TCP: 45 e0 00 50 4b ad 40 00 ff 06 50 ca ac 1b 1c 1d 0a 0b 0c 0d 00 b3 c4 fa fa dd 6d e9 78 7a 1d e0 f0 12 ff ff e2 db 00 00 02 04 05 b4 1d 24 54 3d b0 c3 f9 f3 39 ca c5 60 1c 6c c0 7b d1 c9 a3 05 a8 88 5f 33 b9 46 66 93 a0 5d 2b d3 07 58 19 dc MAC: b0 c3 f9 f3 39 ca c5 60 1c 6c c0 7b d1 c9 a3 05 a8 88 5f 33 b9 46 66 93 a0 5d 2b d3 07 58 19 dc A.3.1.3. Send (Client) Non-SYN (Covers Options) Send_other_traffic_key: fa a5 10 73 c7 fc 24 0a 39 58 a3 6b d0 75 f9 85 1b e7 7a 0d 53 90 6a e7 82 60 c0 f8 19 cc 84 2b IPv4/TCP: 45 e0 00 8f fb 4f 40 00 ff 06 a0 e8 0a 0b 0c 0d ac 1b 1c 1d c4 fa 00 b3 78 7a 1d e0 fa dd 6d ea e0 18 01 04 d4 b0 00 00 1d 24 3d 54 f6 ff 91 b4 76 df f7 5b 47 0d dd 0a 40 8b f9 85 13 00 1a d1 92 c9 6e 38 3b fc af 17 eb 9b 88 79 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 da bf 00 b4 0a 0b 0c 0d 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 da bf 02 08 40 06 00 64 00 01 01 00 MAC: f6 ff 91 b4 76 df f7 5b 47 0d dd 0a 40 8b f9 85 13 00 1a d1 92 c9 6e 38 3b fc af 17 eb 9b 88 79 A.3.1.4. Receive (Server) Non-SYN (Covers Options) Bonica, et al. Expires 4 May 2027 [Page 15] Internet-Draft tcp-ao-algs October 2026 Receive_other_traffic_key: 16 8d 69 c0 a9 14 fe be f9 24 1b 1c d1 de e3 19 86 cc a6 58 68 46 ba e0 f0 9d 9a 7f aa 33 d4 c1 IPv4/TCP: 45 e0 00 8f b9 14 40 00 ff 06 e3 23 ac 1b 1c 1d 0a 0b 0c 0d 00 b3 c4 fa fa dd 6d ea 78 7a 1e 23 e0 18 01 00 98 11 00 00 1d 24 54 3d 0f 77 7c 07 eb ae 61 b7 71 f3 16 5c c4 d4 7b ae 93 f7 c5 69 45 18 b9 8c 55 92 e6 c6 b1 ff 6d 54 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 da c0 00 b4 ac 1b 1c 1d 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 da c0 02 08 40 06 00 64 00 01 01 00 MAC: 0f 77 7c 07 eb ae 61 b7 71 f3 16 5c c4 d4 7b ae 93 f7 c5 69 45 18 b9 8c 55 92 e6 c6 b1 ff 6d 54 A.3.2. KMAC256 (Omits TCP Options) A.3.2.1. Send (Client) SYN (Omits Options) Client ISN = 0x389bed71 Send_SYN_traffic_key: 0a 14 73 b7 6e 34 d8 0a c5 dc 7e 31 07 8a 8d a3 f9 7f 8a 25 79 95 d9 69 ce ea 2a 7f 1f 26 ae 68 IPv4/TCP: 45 e0 00 50 f2 2e 40 00 ff 06 aa 48 0a 0b 0c 0d ac 1b 1c 1d da 1c 00 b3 38 9b ed 71 00 00 00 00 f0 02 ff ff 8b f0 00 00 02 04 05 b4 1d 24 3d 54 80 9c 66 fc f8 2f c9 8d d4 6a c9 4b ee fa 44 b4 ce 8a bb 95 1a fd 97 c3 8a e1 d6 fb f6 f5 31 fb MAC: 80 9c 66 fc f8 2f c9 8d d4 6a c9 4b ee fa 44 b4 ce 8a bb 95 1a fd 97 c3 8a e1 d6 fb f6 f5 31 fb A.3.2.2. Receive (Server) SYN-ACK (Omits Options) Bonica, et al. Expires 4 May 2027 [Page 16] Internet-Draft tcp-ao-algs October 2026 Server ISN = 0xd3844a6f Receive_SYN_traffic_key: 78 55 de 82 11 7e fc 48 48 fd c6 c9 a7 de 50 fd 87 74 3a 95 38 c1 a7 24 a5 f1 37 96 6c 08 ce e3 IPv4/TCP: 45 e0 00 50 6c c0 40 00 ff 06 2f b7 ac 1b 1c 1d 0a 0b 0c 0d 00 b3 da 1c d3 84 4a 6f 38 9b ed 72 f0 12 ff ff 8d 0f 00 00 02 04 05 b4 1d 24 54 3d 26 95 98 5f 00 25 e1 9f d7 1d d8 4d 6c 95 6d 98 50 0a c6 43 a9 d5 05 f2 fc 49 7d 79 2d e8 74 4a MAC: 26 95 98 5f 00 25 e1 9f d7 1d d8 4d 6c 95 6d 98 50 0a c6 43 a9 d5 05 f2 fc 49 7d 79 2d e8 74 4a A.3.2.3. Send (Client) Non-SYN (Omits Options) Send_other_traffic_key: 64 50 fb e2 99 2d 8a 7e f4 63 7f dd 2c b4 60 69 34 fc c4 25 3b 12 ed 5e e6 cf 61 e4 d6 ca 8c c4 IPv4/TCP: 45 e0 00 8f ee 91 40 00 ff 06 ad a6 0a 0b 0c 0d ac 1b 1c 1d da 1c 00 b3 38 9b ed 72 d3 84 4a 70 e0 18 01 04 d2 c0 00 00 1d 24 3d 54 c4 ba d4 2d 4f 1f 44 d7 b0 82 de 28 88 aa 2b d9 70 53 97 bd f7 92 9c 23 d4 02 00 ea 96 f6 13 4a ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 da bf 00 b4 0a 0b 0c 0d 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 da bf 02 08 40 06 00 64 00 01 01 00 MAC: c4 ba d4 2d 4f 1f 44 d7 b0 82 de 28 88 aa 2b d9 70 53 97 bd f7 92 9c 23 d4 02 00 ea 96 f6 13 4a A.3.2.4. Receive (Server) Non-SYN (Omits Options) Bonica, et al. Expires 4 May 2027 [Page 17] Internet-Draft tcp-ao-algs October 2026 Receive_other_traffic_key: 78 55 de 82 11 7e fc 48 48 fd c6 c9 a7 de 50 fd 87 74 3a 95 38 c1 a7 24 a5 f1 37 96 6c 08 ce e3 IPv4/TCP: 45 e0 00 8f 6a 21 40 00 ff 06 32 17 ac 1b 1c 1d 0a 0b 0c 0d 00 b3 da 1c d3 84 4a 70 38 9b ed 72 e0 18 01 00 2d 22 00 00 1d 24 54 3d e6 53 a6 93 43 d9 00 8b 0b ee 8b 85 9e 3b 01 a4 00 0f 9b 93 e6 e8 0f 8c bc 54 69 c2 1e 21 87 ac ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 da c0 00 b4 ac 1b 1c 1d 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 da c0 02 08 40 06 00 64 00 01 01 00 MAC: e6 53 a6 93 43 d9 00 8b 0b ee 8b 85 9e 3b 01 a4 00 0f 9b 93 e6 e8 0f 8c bc 54 69 c2 1e 21 87 ac A.4. IPv6 HMAC-SHA256 Output Test Vectors A.4.1. HMAC-SHA256 (Default - Covers TCP Options) A.4.1.1. Send (Client) SYN (Covers Options) Client ISN = 0x176a833f Send_SYN_traffic_key: c1 da af dc 82 db 45 22 3d 30 08 ec 48 17 7f 09 11 a5 91 3a 43 d0 c9 3a 6d eb a5 21 7c d5 10 37 IPv6/TCP: 6e 08 91 dc 00 3c 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 f7 e4 00 b3 17 6a 83 3f 00 00 00 00 f0 02 ff ff a7 f7 00 00 02 04 05 a0 1d 24 3d 54 52 41 b2 5f 47 e9 5a 77 d4 08 ef 2c ce 9e f4 ee ee 9b 0d 79 47 11 d2 e4 8f 86 12 f6 25 1e 6c f5 MAC: 52 41 b2 5f 47 e9 5a 77 d4 08 ef 2c ce 9e f4 ee ee 9b 0d 79 47 11 d2 e4 8f 86 12 f6 25 1e 6c f5 A.4.1.2. Receive (Server) SYN-ACK (Covers Options) Bonica, et al. Expires 4 May 2027 [Page 18] Internet-Draft tcp-ao-algs October 2026 Server ISN = 0x3f51994b Receive_SYN_traffic_key: e0 20 78 20 1b b6 29 3a 09 cb 3d 6a 1f 89 fa 28 77 92 f1 70 be 5f f8 a6 c5 d3 d5 ab a9 96 bc c2 IPv6/TCP: 6e 01 00 9e 00 3c 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 b3 f7 e4 3f 51 99 4b 17 6a 83 40 f0 12 ff ff 37 f3 00 00 02 04 05 a0 1d 24 54 3d df 71 32 6e 6a 00 d8 21 10 bc 92 75 fd a7 ed 79 c1 4d 71 58 db 0f f5 fc f9 f9 65 b7 17 0a 9c 09 MAC: df 71 32 6e 6a 00 d8 21 10 bc 92 75 fd a7 ed 79 c1 4d 71 58 db 0f f5 fc f9 f9 65 b7 17 0a 9c 09 A.4.1.3. Send (Client) Non-SYN (Covers Options) Send_other_traffic_key: 00 15 82 70 f0 1b 12 11 d9 7a eb 0f 2d a1 6a 22 84 20 86 62 5c 84 02 bb 0b 63 ae 6e 0d b0 e5 14 IPv6/TCP: 6e 08 91 dc 00 7b 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 f7 e4 00 b3 17 6a 83 40 3f 51 99 4c e0 18 01 00 19 d9 00 00 1d 24 3d 54 e3 af f0 1c 67 71 f1 d6 23 8d 47 40 d7 d4 e2 35 11 5f 6f 0a 28 7d f7 1c 51 0a 44 60 3b e8 df 3b ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 fd e8 00 b4 01 01 01 79 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 fd e8 02 08 40 06 00 64 00 01 01 00 MAC: e3 af f0 1c 67 71 f1 d6 23 8d 47 40 d7 d4 e2 35 11 5f 6f 0a 28 7d f7 1c 51 0a 44 60 3b e8 df 3b A.4.1.4. Receive (Server) Non-SYN (Covers Options) Bonica, et al. Expires 4 May 2027 [Page 19] Internet-Draft tcp-ao-algs October 2026 Receive_other_traffic_key: e0 20 78 20 1b b6 29 3a 09 cb 3d 6a 1f 89 fa 28 77 92 f1 70 be 5f f8 a6 c5 d3 d5 ab a9 96 bc c2 IPv6/TCP: 6e 01 00 9e 00 7b 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 b3 f7 e4 3f 51 99 4c 17 6a 83 83 e0 18 01 00 03 f8 00 00 1d 24 54 3d 83 d1 57 f7 c3 f9 cd de a2 b2 0a c0 1b 49 24 8d aa 8a 5c 64 50 85 96 8c 21 58 dc 0f c3 1b 97 c4 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 fd e8 00 b4 01 01 01 7a 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 fd e8 02 08 40 06 00 64 00 01 01 00 MAC: 83 d1 57 f7 c3 f9 cd de a2 b2 0a c0 1b 49 24 8d aa 8a 5c 64 50 85 96 8c 21 58 dc 0f c3 1b 97 c4 A.4.2. HMAC-SHA256 (Omits TCP Options) A.4.2.1. Send (Client) SYN (Omits Options) Client ISN = 0x020c1e69 Send_SYN_traffic_key: cc de 26 1c 40 80 79 8c b3 e6 de c2 fd 10 04 e2 15 67 ed 9b 96 12 aa ce f8 6b 52 ed 0d 9f 9c af IPv6/TCP: 6e 07 8f cd 00 3c 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 c6 cd 00 b3 02 0c 1e 69 00 00 00 00 f0 02 ff ff 95 d0 00 00 02 04 05 a0 1d 24 3d 54 b1 79 ff 7d b3 11 ed ca c8 ca 65 f0 bd 68 d1 c3 e3 9a 2e 83 24 18 53 1a 01 93 5f 27 25 3b 16 d1 MAC: b1 79 ff 7d b3 11 ed ca c8 ca 65 f0 bd 68 d1 c3 e3 9a 2e 83 24 18 53 1a 01 93 5f 27 25 3b 16 d1 A.4.2.2. Receive (Server) SYN-ACK (Omits Options) Bonica, et al. Expires 4 May 2027 [Page 20] Internet-Draft tcp-ao-algs October 2026 Server ISN = 0xeba3734d Receive_SYN_traffic_key: 05 37 33 e3 ef 40 1b d7 e9 92 f3 cb 03 8b ac 18 a2 bf 90 91 b1 ad dd 5e f9 39 3f 3c ab 60 d4 5e IPv6/TCP: 6e 0a 7e 1f 00 3c 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 b3 c6 cd eb a3 73 4d 02 0c 1e 6a f0 12 ff ff 01 54 00 00 02 04 05 a0 1d 24 54 3d a7 6b 75 39 92 4c 50 62 f1 7e ea c6 22 0d 9f 80 82 cf a5 1c 6a ab 29 8d 26 88 47 48 d3 d3 b9 73 MAC: a7 6b 75 39 92 4c 50 62 f1 7e ea c6 22 0d 9f 80 82 cf a5 1c 6a ab 29 8d 26 88 47 48 d3 d3 b9 73 A.4.2.3. Send (Client) Non-SYN (Omits Options) Send_other_traffic_key: 80 67 5f 71 25 52 35 f8 68 d9 7b b4 a9 76 d7 ad c7 d5 66 d2 25 73 24 dc 2b ea 79 c2 5f d6 41 ee IPv6/TCP: 6e 07 8f cd 00 7b 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 c6 cd 00 b3 02 0c 1e 6a eb a3 73 4e e0 18 01 00 b7 ae 00 00 1d 24 3d 54 83 20 b1 08 b8 3c e9 c5 03 f8 a5 c8 81 f5 9a 5e 15 d0 35 16 8e 46 cd 23 a0 52 e3 05 a5 19 be 9d ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 fd e8 00 b4 01 01 01 79 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 fd e8 02 08 40 06 00 64 00 01 01 00 MAC: 83 20 b1 08 b8 3c e9 c5 03 f8 a5 c8 81 f5 9a 5e 15 d0 35 16 8e 46 cd 23 a0 52 e3 05 a5 19 be 9d A.4.2.4. Receive (Server) Non-SYN (Omits Options) Bonica, et al. Expires 4 May 2027 [Page 21] Internet-Draft tcp-ao-algs October 2026 Receive_other_traffic_key: 05 37 33 e3 ef 40 1b d7 e9 92 f3 cb 03 8b ac 18 a2 bf 90 91 b1 ad dd 5e f9 39 3f 3c ab 60 d4 5e IPv6/TCP: 6e 0a 7e 1f 00 7b 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 b3 c6 cd eb a3 73 4e 02 0c 1e ad e0 18 01 00 69 23 00 00 1d 24 54 3d 37 b8 f9 b9 ac a4 13 75 fb 09 25 1d 1a c9 78 48 c8 ac f2 4f 94 ea 65 47 e5 a0 01 c6 7d 08 a2 9c ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 fd e8 00 b4 01 01 01 7a 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 fd e8 02 08 40 06 00 64 00 01 01 00 MAC: 37 b8 f9 b9 ac a4 13 75 fb 09 25 1d 1a c9 78 48 c8 ac f2 4f 94 ea 65 47 e5 a0 01 c6 7d 08 a2 9c A.5. IPv6 KMAC256 Output Test Vectors A.5.1. KMAC256 (Default - Covers TCP Options) A.5.1.1. Send (Client) SYN (Covers Options) Client ISN = 0x193cccec Send_SYN_traffic_key: d2 d7 cb ea 4e 15 6b 75 c8 c8 f6 42 4d 0a 71 b6 f5 cd c9 6c 8e 0e 65 01 dc 28 98 00 2e db 51 d8 IPv6/TCP: 6e 04 a7 06 00 3c 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 f8 5a 00 b3 19 3c cc ec 00 00 00 00 f0 02 ff ff 06 4b 00 00 02 04 05 a0 1d 24 3d 54 71 3b 4f 3f 22 71 26 60 28 a4 87 c0 62 b1 b2 96 23 ab cb 7e 5f ee 98 af 53 92 b1 3b 93 8c 7e fc MAC: 71 3b 4f 3f 22 71 26 60 28 a4 87 c0 62 b1 b2 96 23 ab cb 7e 5f ee 98 af 53 92 b1 3b 93 8c 7e fc Bonica, et al. Expires 4 May 2027 [Page 22] Internet-Draft tcp-ao-algs October 2026 A.5.1.2. Receive (Server) SYN-ACK (Covers Options) Server ISN = 0xa6744ecb Receive_SYN_traffic_key: c8 f9 c7 65 d4 05 85 e7 e2 34 63 65 b1 f5 7f ac 9b 80 1e cc d3 c9 68 a0 22 39 7c a0 00 e9 cf bf IPv6/TCP: 6e 06 15 20 00 3c 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 b3 f8 5a a6 74 4e cb 19 3c cc ed f0 12 ff ff f5 08 00 00 02 04 05 a0 1d 24 54 3d cc 23 04 92 f5 21 b9 06 62 82 0f 6d 01 b2 d1 13 9f 5a c8 44 f8 2d 26 f4 5c 5e a2 4f 20 c2 69 5a MAC: cc 23 04 92 f5 21 b9 06 62 82 0f 6d 01 b2 d1 13 9f 5a c8 44 f8 2d 26 f4 5c 5e a2 4f 20 c2 69 5a A.5.1.3. Send (Client) Non-SYN (Covers Options) Send_other_traffic_key: 2a 86 ea c4 60 ac 2a 76 52 40 1d 08 d9 41 32 41 fb 32 15 b0 8e 42 21 9d dc 93 1c 23 2f d0 35 14 IPv6/TCP: 6e 04 a7 06 00 7b 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 f8 5a 00 b3 19 3c cc ed a6 74 4e cc e0 18 01 00 4b 77 00 00 1d 24 3d 54 a4 d8 1a 50 a9 6e 72 e1 ff 45 49 62 b1 43 eb 5a f6 6c 40 bb d4 09 67 f8 9a d5 38 7c 50 19 b0 f3 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 fd e8 00 b4 01 01 01 79 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 fd e8 02 08 40 06 00 64 00 01 01 00 MAC: a4 d8 1a 50 a9 6e 72 e1 ff 45 49 62 b1 43 eb 5a f6 6c 40 bb d4 09 67 f8 9a d5 38 7c 50 19 b0 f3 A.5.1.4. Receive (Server) Non-SYN (Covers Options) Bonica, et al. Expires 4 May 2027 [Page 23] Internet-Draft tcp-ao-algs October 2026 Receive_other_traffic_key: c8 f9 c7 65 d4 05 85 e7 e2 34 63 65 b1 f5 7f ac 9b 80 1e cc d3 c9 68 a0 22 39 7c a0 00 e9 cf bf IPv6/TCP: 6e 06 15 20 00 7b 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 b3 f8 5a a6 74 4e cc 19 3c cd 30 e0 18 01 00 68 1d 00 00 1d 24 54 3d 96 9f dc 9c 46 64 f6 e3 14 64 e6 06 77 a8 a8 87 7f 47 7e aa df ed a0 4c 97 71 a8 fc bf 12 8b a8 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 fd e8 00 b4 01 01 01 7a 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 fd e8 02 08 40 06 00 64 00 01 01 00 MAC: 96 9f dc 9c 46 64 f6 e3 14 64 e6 06 77 a8 a8 87 7f 47 7e aa df ed a0 4c 97 71 a8 fc bf 12 8b a8 A.5.2. KMAC256 (Omits TCP Options) A.5.2.1. Send (Client) SYN (Omits Options) Client ISN = 0xb01da74a Send_SYN_traffic_key: 9e 3f 17 70 15 9b dd d9 01 51 18 13 10 e9 7e 85 f9 84 2c dd 67 fc b6 e1 eb 66 e2 58 4a 8b aa 92 IPv6/TCP: 6e 09 3d 76 00 3c 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 f2 88 00 b3 b0 1d a7 4a 00 00 00 00 f0 02 ff ff 10 03 00 00 02 04 05 a0 1d 24 3d 54 45 6b 05 e1 27 ee 95 36 d2 87 d3 16 65 4c 90 02 8c cc 78 13 a5 5d 87 23 28 86 ba dd 69 20 37 ae MAC: 45 6b 05 e1 27 ee 95 36 d2 87 d3 16 65 4c 90 02 8c cc 78 13 a5 5d 87 23 28 86 ba dd 69 20 37 ae A.5.2.2. Receive (Server) SYN-ACK (Omits Options) Bonica, et al. Expires 4 May 2027 [Page 24] Internet-Draft tcp-ao-algs October 2026 Server ISN = 0xa6246145 Receive_SYN_traffic_key: fa b8 f8 8f 4c 4a ed 05 ff 0d 1e 8a d5 3b 25 ba 59 2d 0e ae fb 4b a2 70 77 3b 43 9e fc 7c 0d 04 IPv6/TCP: 6e 0c 60 0a 00 3c 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 b3 f2 88 a6 24 61 45 b0 1d a7 4b f0 12 ff ff ac 19 00 00 02 04 05 a0 1d 24 54 3d 35 b3 0f 1f a5 81 ed d6 1f 6f 1d be e7 ea 91 ea d3 45 cc 98 8e a2 de 25 4e 3e 9e 85 61 de b4 00 MAC: 35 b3 0f 1f a5 81 ed d6 1f 6f 1d be e7 ea 91 ea d3 45 cc 98 8e a2 de 25 4e 3e 9e 85 61 de b4 00 A.5.2.3. Send (Client) Non-SYN (Omits Options) Send_other_traffic_key: a1 04 09 79 51 2f 15 43 c9 0a c8 f5 e7 30 9c 86 c4 86 16 18 a1 f7 d4 ad 11 e6 73 1b dc e3 3f 9d IPv6/TCP: 6e 09 3d 76 00 7b 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 f2 88 00 b3 b0 1d a7 4b a6 24 61 46 e0 18 01 00 04 45 00 00 1d 24 3d 54 7a 97 27 5d ce c2 ee 0e a1 5a 74 32 7d 56 c6 c3 02 61 36 2a 9c cb b9 c8 8a 1b f5 35 b2 77 58 8d ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 fd e8 00 b4 01 01 01 79 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 fd e8 02 08 40 06 00 64 00 01 01 00 MAC: 7a 97 27 5d ce c2 ee 0e a1 5a 74 32 7d 56 c6 c3 02 61 36 2a 9c cb b9 c8 8a 1b f5 35 b2 77 58 8d A.5.2.4. Receive (Server) Non-SYN (Omits Options) Bonica, et al. Expires 4 May 2027 [Page 25] Internet-Draft tcp-ao-algs October 2026 Receive_other_traffic_key: fa b8 f8 8f 4c 4a ed 05 ff 0d 1e 8a d5 3b 25 ba 59 2d 0e ae fb 4b a2 70 77 3b 43 9e fc 7c 0d 04 IPv6/TCP: 6e 0c 60 0a 00 7b 06 40 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 02 fd 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 00 b3 f2 88 a6 24 61 46 b0 1d a7 8e e0 18 01 00 37 cd 00 00 1d 24 54 3d 2e c4 1d a3 fa 63 39 50 10 bc 84 ca d4 61 33 dc 54 c9 e7 5d b4 67 a4 23 4a 8d 7b 23 4c 5b c2 8f ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff 00 43 01 04 fd e8 00 b4 01 01 01 7a 26 02 06 01 04 00 01 00 01 02 02 80 00 02 02 02 00 02 02 42 00 02 06 41 04 00 00 fd e8 02 08 40 06 00 64 00 01 01 00 MAC: 2e c4 1d a3 fa 63 39 50 10 bc 84 ca d4 61 33 dc 54 c9 e7 5d b4 67 a4 23 4a 8d 7b 23 4c 5b c2 8f Authors' Addresses Ron Bonica HPE United States of America Email: ronald.bonica@hpe.com Tony Li HPE United States of America Email: tony.li@tony.li Ping Chen HPE Canada Email: ping.chen@hpe.com Prashant Kumar HPE India Email: prashant.kumar5@hpe.com Bonica, et al. Expires 4 May 2027 [Page 26] Internet-Draft tcp-ao-algs October 2026 Reji Thomas Arista Networks India Email: reji.thomas@arista.com Sujeet Nayak Ammunje Cisco Systems India Email: sua@cisco.com Ayan Banerjee Cisco Systems United States of America Email: ayabaner@cisco.com Bonica, et al. Expires 4 May 2027 [Page 27]