Cryptanalysis of General Lu-Lee Type Systems

摘要

The Lu-Lee public key cryptosystem and Adiga-Shankar's modification are considered to be insecure with cryptanalysis by integer linear programing, since only 2 or 3 unknown message blocks are used in the modular linear equation for encryption procedure. Unfortunately integer linear programming algorithms falls in trouble with more unknowns. In this paper we present a probabilistic algorithm for cryptanalysis of general Lu-Lee type systems with n message blocks. The new algorithm is base on lattice reduction and succeeds to break Lu-Lee type systems with up to 68 message blocks.