Extension Field Cancellation: A new central trapdoor for multivariate quadratic systems

Alan Szepieniec*, Jintai Ding, Bart Preneel

*Corresponding author for this work

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

25 Citations (Scopus)

Abstract

This paper introduces a new central trapdoor for multivariate quadratic (MQ) public-key cryptosystems that allows for encryption, in contrast to time-tested MQ primitives such as Unbalanced Oil and Vinegar or Hidden Field Equations which only allow for signatures. Our construction is a mixed-field scheme that exploits the commutativity of the extension field to dramatically reduce the complexity of the extension field polynomial implicitly present in the public key. However, this reduction can only be performed by the user who knows concise descriptions of two simple polynomials, which constitute the private key. After applying this transformation, the plaintext can be recovered by solving a linear system. We use the minus and projection modifiers to inoculate our scheme against known attacks. A straightforward C++ implementation confirms the efficient operation of the public key algorithms.

Original languageEnglish
Title of host publicationPost-Quantum Cryptography - 7th International Workshop, PQCrypto 2016, Proceedings
EditorsTsuyoshi Takagi
PublisherSpringer Verlag
Pages182-196
Number of pages15
ISBN (Print)9783319293592
DOIs
Publication statusPublished - 2016
Externally publishedYes
Event7th International Workshop on Post-Quantum Cryptography, PQCrypto 2016 - Fukuoka, Japan
Duration: 24 Feb 201626 Feb 2016

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume9606
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference7th International Workshop on Post-Quantum Cryptography, PQCrypto 2016
Country/TerritoryJapan
CityFukuoka
Period24/02/1626/02/16

Keywords

  • Encryption
  • Mixed-field
  • MQ
  • Multivariate
  • Postquantum
  • Public-key
  • Quadratic
  • Trapdoor

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