• Journal of the Korea Institute of Information Security & Cryptology
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• v.22 no.3
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• pp.495-504
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• 2012

This paper presents various speed optimization techniques for software implementation of the HIGHT block cipher on CPUs and GPUs. We considered 32-bit and 64-bit operating systems for CPU implementations. After we applied the bit-slicing and byte-slicing techniques to HIGHT, the encryption speed recorded 1.48Gbps over the intel core i7 920 CPU with a 64-bit operating system, which is up to 2.4 times faster than the previous implementation. We also implemented HIGHT on an NVIDIA GPU equipped with CUDA, and applied various optimization techniques, such as storing most frequently used data like subkeys and the F lookup table in the shared memory; and using coalesced access when reading data from the global memory. To our knowledge, this is the first result that implements and optimizes HIGHT on a GPU. We verified that the byte-slicing technique guarantees a speed-up of more than 20%, resulting a speed which is 31 times faster than that on a CPU.

• Journal of Korea Society of Industrial Information Systems
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• v.17 no.3
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• pp.9-17
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• 2012

In this paper, we propose a SPN 256 bit block cipher so called XSB(eXtended SPN Block cipher) which has a symmetric structure in encryption and decryption. The proposed XSB is composed of the even numbers of N rounds where the first half of them, 1 to N/2-1 round, applies a pre-function and the last half of them, N/2+1 to N round, employs a post-function. Each round consists of a round key addition layer, a substiution layer, a byte exchange layer and a diffusion layer. And a symmetry layer is located in between the pre-function layer and the post-function layer. The symmetric layer is composed with a multiple simple bit slice involution S-Boxes. The bit slice involution S-Box symmetric layer increases difficult to attack cipher by Square attack, Boomerang attack, Impossible differentials cryptanalysis etc.