TY - GEN
T1 - Cryptanalysis of a public key cryptosystem based on diophantine equations via weighted LLL reduction
AU - Ding, Jintai
AU - Kudo, Momonari
AU - Okumura, Shinya
AU - Takagi, Tsuyoshi
AU - Tao, Chengdong
N1 - Publisher Copyright:
© Springer International Publishing Switzerland 2016.
PY - 2016
Y1 - 2016
N2 - Okumura proposed a candidate of post-quantum cryptosystem based on Diophantine equations of degree increasing type (DEC). Sizes of public keys in DEC are small, e.g., 1,200 bits for 128 bit security, and it is a strongly desired property in post-quantum erea. In this paper, we propose a polynomial time attack against DEC. We show that the one-wayness of DEC is reduced to finding special (relatively) short vectors in some lattices. The usual LLL algorithm does not work well for finding the most important target vector in our attack. The most technical point of our method is to heuristically find a special norm called a weighted norm to find the most important target vector. We call this method "weighted LLL algorithm" in this paper. Our experimental results suggest that our attack can break the one-wayness of DEC for 128 bit security with sufficiently high probability.
AB - Okumura proposed a candidate of post-quantum cryptosystem based on Diophantine equations of degree increasing type (DEC). Sizes of public keys in DEC are small, e.g., 1,200 bits for 128 bit security, and it is a strongly desired property in post-quantum erea. In this paper, we propose a polynomial time attack against DEC. We show that the one-wayness of DEC is reduced to finding special (relatively) short vectors in some lattices. The usual LLL algorithm does not work well for finding the most important target vector in our attack. The most technical point of our method is to heuristically find a special norm called a weighted norm to find the most important target vector. We call this method "weighted LLL algorithm" in this paper. Our experimental results suggest that our attack can break the one-wayness of DEC for 128 bit security with sufficiently high probability.
KW - Diophantine equation
KW - Post-quantum cryptosystem
KW - Weighted LLL reduction
UR - http://www.scopus.com/inward/record.url?scp=84987933707&partnerID=8YFLogxK
U2 - 10.1007/978-3-319-44524-3_18
DO - 10.1007/978-3-319-44524-3_18
M3 - Conference Proceeding
AN - SCOPUS:84987933707
SN - 9783319445236
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 305
EP - 315
BT - Advances in Information and Computer Security - 11th International Workshop on Security, IWSEC 2016, Proceedings
A2 - Yoshioka, Katsunari
A2 - Ogawa, Kazuto
PB - Springer Verlag
T2 - 11th International Workshop on Security on Advances in Information and Computer Security, IWSEC 2016
Y2 - 12 September 2016 through 14 September 2016
ER -