Improved Related-Key Differential Attacks on Reduced-Round LBlock
At ACNS 2011, Wu and Zhang proposed a new lightweight block cipher which is named LBlock. The design rationale of LBlock considers the trade-offs between security against cryptanalyses and performance in low-resource implementations. In this paper, we present new attacks on reduced-round LBlock using related-key differential cryptanalysis. Firstly, we construct a new related-key boomerang distinguishing attack on 16-round LBlock. Secondly, we construct a key recovery attack on 22-round LBlock based on a 16-round related-key truncated differential. In contrast to the published cryptanalysis results of reduced-round LBlock, our attacks have advantages on data and computational complexities.
KeywordsLightweight block cipher Differential analysis Related-key boomerang attack LBlock
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