ENCRYPTION METHOD OF 128-BIT LIGHTWEIGHT BLOCK CIPHER SUITABLE FOR SIDE-CHANNEL COUNTERMEASURES

摘要

The present disclosure discloses a method for cryptographically processing data and an apparatus using the same. Specifically, according to the method according to the present disclosure, for a natural number M, which is a predetermined number of rounds, the first to M+1 round keys are generated, and a plaintext is encrypted using the generated first to M+1 round keys. The ciphertext is calculated from, specifically, a master key is generated, and first to M+1 round keys are generated as a result of performing an operation including XOR on the master key and the constant for each round, and the round Star constants are set differently for each round. In calculating the ciphertext from the plaintext, a first median value is calculated from the plaintext using the first round key, and for n=1, ..., M, sequentially (i) the nth median value The substitution operation on the result of applying an operation including bit permutation to the result of applying an operation including substitution operation to or applying an operation including the inter-bit position conversion operation to the nth intermediate value It is achieved by repeatedly performing the step of calculating the nth result value by applying an operation including and (ii) calculating the n+1th intermediate value from the nth result value using the n+1th round key, and The median value of the M+1 is calculated as a ciphertext.