A New Knapsack Public-Key Cryptosystem

A new knapsack type public key cryptosystem is proposed by constructing an easy knapsack problem. The cryptosystem is shown to be secure against Shamir´s key recovery attack in that it does not use a super-increasing knapsack sequence in the construction process. The cryptosystem is also invulnerable to low density attack in that it obtains a relatively high density. It is shown that the cryptosystem resists some brute force attacks and the simultaneous Diophantine approximation attack. It only performs n addition operations for the cryptosystem to encrypt a plaintext, and the decryption algorithm only carries out n modular 2 divisions. Therefore, the cryptosystem is efficient with respect to the encryption and the decryption. Furthermore, the cryptosystem is suited for software and hardware implementations.