Improved Single-Key Attack on Reduced-Round LED

Abstract

In this paper, On the basis of the single-key model and the differential analysis principle, we propose the improved attacks on the new low-cost LED block cipher which revisits meet-in-the-middle attack. More precisely, we choose a differential with high probability firstly. Since we have guessed some key nibbles to check whether the plaintext pair follows the differential characteristic, we construct the $\delta$-set from plaintext which is used to match the right key under meet-in-the-middle attack. Finally, the key candidates are recovered by removing the values that do not content conditions. Hence the secret key bits can be recovered with very low complexity 2^33, which is faster than other previous papers. We attack the complete six rounds on LED-64, and we can expand to more rounds on LED-128. At the present time, it is an efficient attack on six-rounds of LED-64.