Date Added: Sep 2012
The authors considered cryptanalysis of a knapsack-type public key cryptosystem. This cryptosystem uses a combination permutation algorithm in the encryption phase to avoid the low density attack by keeping the density high. This cryptosystem is vulnerable to LLL-lattice basis reduction algorithm, since it uses a super-increasing sequence as a private key and attempt to hide this sequence with modular multiplication for constructing the public key. But as they showed, the modular multiplication cannot hide the superincreasing sequence.