• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.2
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• pp.457-465
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• 2015

Internet of Things(IoT) technologies should be able to communication with various embedded platforms. We will need to select an appropriate cryptographic algorithm in various embedded environments because we should consider security elements in IoT communications. Therefore the lightweight block cryptographic algorithm is essential for secure communication between these kinds of embedded platforms. However, the lightweight block cryptographic algorithm has a vulnerability which can be leaked in side channel analysis. Thus we also have to consider side channel countermeasure. In this paper, we will propose the scenario of side channel analysis and confirm the vulnerability for HIGHT algorithm which is composed of ARX structure. Additionally, we will suggest countermeasure for HIGHT against side channel analysis. Finally, we will explain how much the effectiveness can be provided through comparison between countermeasure for AES and HIGHT.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.1
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• pp.15-24
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• 2018

In this paper, we explain a method of appproximating the differentials probability using a SAT solver. It is possible to increase the probability by constructing the differential characteristic which already known to differentials with a SAT solver. We apply our method to SPECK32 and SPECK48. As a result, we introduced a SPECK32's 10-round differentials with a probability of$2^{-30.39}$, and SPECK48's 12-round differentials with probability of $2^{-46.8}$. Both differentials are new and longer round and higher probability than previous ones. Using the differentials presented in this paper, we improved attacks of SPECK32/64 to 15 round, SPECK48/72 to 16 round, SPECK48/96 to 17 round, which attack 1 more rounds of previous works.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.3
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• pp.401-410
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• 2023

In this paper, we propose optimization methods for implementing SPARKLE, one of the NIST LWC finalists, on a 64-bit ARMv8 processor. The proposed methods consist of two approaches: an implementation using ARM A64 instructions and another using NEON ASIMD instructions. The A64-based implementation is optimized by performing register scheduling to efficiently utilize the available registers on the ARMv8 architecture. By utilizing the optimized A64-based implementation, we can achieve speeds that are 1.69 to 1.81 times faster than the C reference implementation on a Raspberry Pi 4B. The ASIMD-based implementation, on the other hand, optimizes data by parallelizing the ARX-boxes to perform more than three of them concurrently through a single vector instruction. While the general speed of the optimized ASIMD-based implementation is lower than that of the A64-based implementation, it only slows down by 1.2 times compared to the 2.1 times slowdown observed in the A64-based implementation as the block size increases from SPARKLE256 to SPARKLE512. This is an advantage of the ASIMD-based implementation. Therefore, the ASIMD-based implementation is more efficient for SPARKLE variant block cipher or permutation designs with larger block sizes than the original SPARKLE, making it a useful resource.