The Improved Differential Cryptanalysis Of MANTIS

MANTIS is a light-weight tweakable block cipher proposed at CRYPTO 2016 by Beierle.The designer's objective is to achieve an optimal tweakable block cipher design for low-latency,with improved security.MANTIS has 64 bit block size,128 bit key material,64 bit tweak.The designers propose several variants MANTIS that differ only in the number of rounds,with different security claim.For MANTIS-7,designers claim that any adversary who in possession of 2n chosen plain/ciphertext pairs which were obtained under related tweak setting,needs at least 2126-n calls to the encryption function in order to recover the secret key.For MANTIS-5,designers claim security against practical attacks.There is no attack that the data D ? 230 chosen plaintexts or D ? 240 known plaintexts,data time D-T<2126.An attack of MANTIS-5 is proposed by Dobraunig,Eichlseder in FSE 2017.In theory,in the related tweak setting,only 228 chosen plaintexts can be encrypted approximately 238 times to restore all the keys.Then Eichlseder proposed a key recovery attack on MANTIS-6,with a time data complexity of 2108.Based on the analysis of Dobraunigine and Eichlseder's difference character-istics and attack process,a new differential characteristic family including more input difference is found in this paper.In the key recovery attack under the new differential characteristics,we adopt the early filtering technique to further reduce the complexity.We present a new attack based on the new MANTIS-5 differential characteristic,the data complexity is 226.58,the time complexity is 230.95,and the data time complexity is 257.53.We present a new attack based on the new MANTIS-6 differential characteristic,The data complexity is 250.61,the time complexity is 248.61,and the data time complexity is 299.22.