Cryptanalysis of rational multivariate public key cryptosystems

Jintai Ding*, John Wagner

*Corresponding author for this work

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

5 Citations (Scopus)

Abstract

In 1989, Tsujii, Fujioka, and Hirayama proposed a family of multivariate public key cryptosystems, where the public key is given as a set of multivariate rational functions of degree 4. These cryptosystems are constructed via composition of two quadratic rational maps. In this paper, we present the cryptanalysis of this family of cryptosystems. The key point of our attack is to transform a problem of decomposition of two rational maps into a problem of decomposition of two polynomial maps. We develop a new improved 2R decomposition method and other new techniques, which allows us to find an equivalent decomposition of the rational maps to break the system completely. For the example suggested for practical applications, it is very fast to derive an equivalent private key, and it requires only a few seconds on a standard PC.

Original languageEnglish
Title of host publicationPost-Quantum Cryptography - Second International Workshop, PQCrypto 2008, Proceedings
PublisherSpringer Verlag
Pages124-136
Number of pages13
ISBN (Print)3540884025, 9783540884026
DOIs
Publication statusPublished - 2008
Externally publishedYes
Event2nd International Workshop on Post-Quantum Cryptography, PQCrypto 2008 - Cincinnati, OH, United States
Duration: 17 Oct 200819 Oct 2008

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Volume5299 LNCS
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349

Conference

Conference2nd International Workshop on Post-Quantum Cryptography, PQCrypto 2008
Country/TerritoryUnited States
CityCincinnati, OH
Period17/10/0819/10/08

Fingerprint

Dive into the research topics of 'Cryptanalysis of rational multivariate public key cryptosystems'. Together they form a unique fingerprint.

Cite this