Date Added: Nov 2009
In this paper, the authors cryptanalyze two knapsack cryptosystems. The first one is proposed by Hwang et al, which is based on a new permutation algorithm named Permutation Combination Algorithm. They show that this permutation algorithm is useless to the security of the cryptosystem. Because of the special super increasing structure, they can break this cryptosystem use the method provided by Shamir at Crypto'82. The second one is provided by Su et al, which is based on the elliptic curve discrete logarithm and knapsack problem.