NIST Testing of a Knapsack Symmetric Cryptosystem on Hamlin Codes Using Source Block Injections

This article proposes a constructing option for a knapsack symmetric cryptosystem based on Hamlin codes. The paper considers a knapsack cryptosystem with a shared memory and a knapsack packing density of more than one, which provides resistance to the Lagarias - Odlyzhko attack. The authors suggest using the bases of recurrent sequences of finite order that ensure the packing density of the knapsack is more than one. The design of the proposed cryptosystem operates in the block-linking mode and uses a block cipher based on Hamlin codes to construct it. The paper presents an encryption algorithm based on Hamlin codes using injections (mutations) of the original block. The authors have carried out NIST test of a knapsack symmetric cryptosystem on Hamlin codes using injections (mutations) of the original block. The results of the test revealed that injections for binary signatures significantly increase the frequency characteristics and, consequently, the cryptographic strength of the encryption system.