TY - GEN
T1 - Cryptanalysis of rational multivariate public key cryptosystems
AU - Ding, Jintai
AU - Wagner, John
PY - 2008
Y1 - 2008
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=56749105660&partnerID=8YFLogxK
U2 - 10.1007/978-3-540-88403-3_9
DO - 10.1007/978-3-540-88403-3_9
M3 - Conference Proceeding
AN - SCOPUS:56749105660
SN - 3540884025
SN - 9783540884026
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 124
EP - 136
BT - Post-Quantum Cryptography - Second International Workshop, PQCrypto 2008, Proceedings
PB - Springer Verlag
T2 - 2nd International Workshop on Post-Quantum Cryptography, PQCrypto 2008
Y2 - 17 October 2008 through 19 October 2008
ER -