CAKE: Code-Based Algorithm for Key Encapsulation

Paulo S.L.M. Barreto, Shay Gueron, Tim Güneysu, Rafael Misoczki, Edoardo Persichetti, Nicolas Sendrier, Jean Pierre Tillich

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Current widely-used key exchange (KE) mechanisms will be vulnerable to quantum attacks when sufficiently strong quantum computers become available. Therefore, devising quantum-resistant replacements that combine efficiency with solid security guarantees is an important and challenging task. This paper proposes several contributions towards this goal. First, we introduce “CAKE”, a key encapsulation algorithm based on the QC-MDPC McEliece encryption scheme, with two major improvements: (a) the use of ephemeral keys that defeats a recent reaction attack against MDPC decoding of the corresponding encryption scheme and (b) a highly efficient key generation procedure for QC-MDPC-based cryptosystems. Then, we present an authenticated key exchange protocol based on CAKE, which is suitable for the Internet Key Exchange (IKE) standard. We prove that CAKE is IND-CPA secure, that the protocol is SK-Secure, and suggest practical parameters. Compared to other post-quantum schemes, we believe that CAKE is a promising candidate for post-quantum key exchange standardization.

Original languageEnglish
Title of host publicationCryptography and Coding - 16th IMA International Conference, IMACC 2017, Proceedings
EditorsMaire O’Neill
PublisherSpringer Verlag
Number of pages20
ISBN (Print)9783319710440
StatePublished - 2017
Event16th IMA International Conference on Cryptography and Coding, IMACC 2017 - Oxford, United Kingdom
Duration: 12 Dec 201714 Dec 2017

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume10655 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Conference16th IMA International Conference on Cryptography and Coding, IMACC 2017
Country/TerritoryUnited Kingdom

Bibliographical note

Funding Information:
Acknowledgments. Shay Gueron, Tim Güneysu, Nicolas Sendrier and Jean-Pierre Tillich were supported in part by the Commission of the European Communities through the Horizon 2020 program under project number 645622 (PQCRYPTO). Shay Gueron was also partially supported by the Israel Science Foundation (grant No. 1018/16). Paulo S. L. M. Barreto was partially supported by Intel and FAPESP through the project “Efficient Post-Quantum Cryptography for Building Advanced Security Applications” (grant No. 2015/50520-6).

Publisher Copyright:
© 2017, Springer International Publishing AG.


  • Code-based cryptography
  • Key exchange
  • Post-quantum cryptography

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science (all)


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