Search

The lightweight block ciphers could be widely used in various applications, such as smart cities, internet of things and cloud computation and so on, in order to protect data and information secure. Midori was a lightweight block cipher proposed in ASIACRYPT 2015. Its block size had two scenarios, i. e, 64 bit and 128 bit, denoted by Midori 64 and Midori 128 respectively. Up to now, there were no results about meet-in-the-middle attacks on Midori 128. This paper developed a meet-inthe-middle attack on 10-round Midori 128 for the first time. Specifically, studying the basic construction and key schedule of Midori 128, this paper constructed a 7-round distinguisher on Midori 128 by using the differential enumeration and key-dependent sieve techniques. Through appending one round at its top and two rounds at its bottom, this paper mounted a meet-in-themiddle attack on 10-round Midori 128. In the attack, time-memory tradeoff technique and some weak subkeys were considered so as to reduce the time complexity of online phase. Finally, the data, time and memory complexities of our attack are 2125 chosen plaintexts, 2126. 510-round encryptions and 2105128-bit blocks, respectively. [ABSTRACT FROM AUTHOR]