IEMS3: An Image Encryption Scheme Using Modified SNOW 3G Algorithm

This paper deals with an updated SNOW 3G key stream generator (KSG). The proposed KSG can be applied to encrypt images in the Internet of Things (IoT) applications. The KSG algorithm replaces the LFSR structure of SNOW 3G by a \(\sigma -\) LFSR of delay blocks of \(64-\) bit input–output and 8 gain matrices. It also incorporates a new feedback polynomial with 8, \(64 \times 64\) coefficient matrices over GF(2). As a nonlinear component, 16, 8 input-8 output parallel S-BOXes are concatenated to produce the 64 input and 64 output S-BOXes S1 and S2. The algorithm generates a 64 bit pseudorandom number in each clock pulse, making the image encryption faster than some existing techniques. We practically justify the algorithms with various security parameter analyses.