New Trapdoors in Knapsack Public-Key Cryptosystem with Two Sequences as Public Key

摘要

Present authors proposed a new class of knasack PKC (KMN PKC) which uses two sequences as the public key. KMN PKC uses a super-increasing sequence as the trapdoor based on Merkle-Hellman knapsack cryptosystem. In this paper, we propose new trapdoors in KMN type knapsack scheme in which two sequences are used as the public key. We also propose the simple class of the proposed scheme. We show that the proposed scheme can be secure against the low-density attack because the density can be made as large as one desires. We also discuss the security of the secret key of the proposed scheme.