CAKE-HI - Compact Authenticated Key Exchange Hiding Identities

Uri Blumenthal; Gene Itkis; Roger Khazan; Brandon Luo; Sean O'Melia; Brian Proulx; David Stott; Gabriel Torres; David A. Wilson

Paper 2026/1749

CAKE-HI - Compact Authenticated Key Exchange Hiding Identities

Uri Blumenthal

, Massachusetts Institute of Technology

Gene Itkis, Massachusetts Institute of Technology

Roger Khazan, Massachusetts Institute of Technology

Brandon Luo, Massachusetts Institute of Technology

Sean O'Melia, Massachusetts Institute of Technology

Brian Proulx

David Stott, Massachusetts Institute of Technology

Gabriel Torres, Massachusetts Institute of Technology

David A. Wilson, Massachusetts Institute of Technology

Abstract

Modern public-key cryptography is threatened by advances in quantum computing. As a result, there has been a shift towards cryptographic algorithms that can resist attacks by a quantum computer. However, these algorithms use significantly longer keys, and produce larger ciphertexts and digital signatures than their classical counterparts. These bigger sizes pose problems for devices that are bandwidth- and/or power-limited, and wish to establish a secure, quantum resistant communication channel with another device. In order to reduce the overhead of using these algorithms in challenging environments while maintaining security posture, we present Compact Authenticated Key Exchange – Hiding Identities (CAKE-HI). To evaluate our protocol, we compare the key exchange handshake size and computational efficiency of mutual authenticated TLS and CAKE-HI. Measurements show that CAKE-HI significantly reduces the handshake size and the computational overhead of establishing a quantum-secure link. In addition, we formalize and prove security properties about CAKE-HI in the symbolic and computational model using the protocol analysis frameworks Verifpal and CryptoVerif.

Metadata

Available format(s): PDF
Category: Cryptographic protocols
Publication info: Preprint.
Keywords: authenticated compact cryptography key ex- change quantum-resilient bandwidth-limited power-limited minimalistic
Contact author(s): uri @ ll mit edu
itkis @ ll mit edu
rkh @ ll mit edu
Brandon Luo @ ll mit edu
sean omelia @ ll mit edu
Brian Proulx @ ll mit edu
David Stott @ ll mit edu
Gabriel Torres @ ll mit edu
David Wilson @ ll mit edu
History: 2026-08-22: approved; 2026-08-20: received; See all versions
Short URL: https://ia.cr/2026/1749
License: CC BY

BibTeX

@misc{cryptoeprint:2026/1749,
      author = {Uri Blumenthal and Gene Itkis and Roger Khazan and Brandon Luo and Sean O'Melia and Brian Proulx and David Stott and Gabriel Torres and David A. Wilson},
      title = {{CAKE}-{HI} - Compact Authenticated Key Exchange Hiding Identities},
      howpublished = {Cryptology {ePrint} Archive, Paper 2026/1749},
      year = {2026},
      url = {https://eprint.iacr.org/2026/1749}
}