Liaison statement
LS on supporting transmission of large identity in EAP-AKA’

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State Posted
Submitted Date 2026-05-29
From Group 3GPP-TSG-SA-WG3
From Contact Tao Wan <t.wan@cablelabs.com>
To Group emu
To Contacts Joseph Salowey <joe@salowey.net>
Peter Yee <peter@akayla.com>
Cc Deb Cooley <debcooley1@gmail.com>
Peter Yee <peter@akayla.com>
Joseph Salowey <joe@salowey.net>
EAP Method Update Discussion List <emu@ietf.org>
Christopher Inacio <stndrds-inacio@andrew.cmu.edu>
Charles Eckel <eckelcu@cisco.com>
Response Contact 3GPP Liaisons Coordinator <3GPPLiaison@etsi.org>
Peter Schmitt <Peter.Schmitt@huawei.com>
Purpose For action
Deadline 2026-08-07 Action Needed
Attachments LS on supporting transmission of large identity in EAP-AKA’
Body 
1.   Overall description

3GPP SA3 has been conducting a study on transitioning to PQC [1], including the
calculation of Subscription Concealed Identifiers (SUCI) using post-quantum
cryptographic (PQC) algorithms. In future, SUCI could be larger than the EAP
MTU of 1020 bytes and Ethernet MTU of 1500 bytes.

SUCI can be sent by a UE to an EAP server in either EAP Response/Identity or
EAP Response/AKA-Identity. However, neither EAP [2] nor EAP-AKA’ [3, 4]
provides fragmentation mechanism to support the transmission of an identity
larger than EAP MTU.

3GPP SA3 kindly requests IETF EMU to consider updating EAP-AKA’ to support the
transmission of an identity larger than EAP MTU.

References

[1] 3GPP TR 33.703. Study on Transitioning to Post Quantum Cryptography (PQC)
in 3GPP (Release 20). [2] IETF RFC 4380. Extensible Authentication Protocol
(EAP). [3] IETF RFC 5448. Improved Extensible Authentication Protocol Method
for 3rd Generation Authentication and Key Agreement (EAP-AKA'). [4] IETF RFC
9048. Improved Extensible Authentication Protocol Method for 3GPP Mobile
Network Authentication and Key Agreement (EAP-AKA').

2.   Actions

To IETF EMU

ACTION:         Please kindly consider the above request and keep 3GPP SA3
informed of the progress.

3.   Dates of next TSG SA WG 3 meetings

SA3#129 24 – 28 August 2026             Prague, Czech
SA3#130 12 – 16 October 2026            Prague, Czech