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

Publisher Copyright:
© 2017, Springer International Publishing AG.


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

ASJC Scopus subject areas

  • Theoretical Computer Science
  • General Computer Science


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