The Boomerang Attacks on BLAKE and BLAKE2

Abstract

Abstract. In this paper, we study the security margins of hash functions BLAKE and BLAKE2 against the boomerang attack. We launch boomerang attacks on all four members of BLAKE and BLAKE2, and compare their complexities. We propose 8.5-round boomerang attacks on both BLAKE-512 and BLAKE2b with complexities 2 464 and 2 474 respectively. We also propose 8-round attacks on BLAKE-256 with complexity 2 198 and 7.5-round attacks on BLAKE2s with complexity 2 184 . We verify the correctness of our analysis by giving practical 6.5-round Type I boomerang quartets for each member of BLAKE and BLAKE2. According to our analysis, some tweaks introduced by BLAKE2 have increased its resistance against boomerang attacks to a certain extent. But on the whole, BLAKE still has higher a secure margin than BLAKE2.

Vulnerabilities and Limitations of MQTT Protocol Used between IoT Devices

“…To assess the security of Blake and Blake2 hashing algorithms, the authors of Reference [7] used a boomerang attack and compare their complexity. Towards this goal, the authors proposed using a 7.5 round-based boomerang attack on Blake2s with a complexity of 2 184 .…”

Cryptanalysis of the LSH hash functions

“…Note: Many previous Type I boomerang results, such as , can only work on the compression functions ( CF of ) or the keyed permutations ( E of ) rather than the whole hash functions ( HF of ). But for LSH, it is equivalent to attack CF , E and HF due to the absence of the feed forward operation and the linearity of the F I N n finalization function.…”

“…Because LSH is an ARX hash function family (only using Modular Add “ +”, Rotation “ ” and XOR “⊕”), we can use the XOR difference and deduce the difference linearly by replacing modular adds (“ +”) with the similar XOR (“⊕”). Besides, following the notations of , we present the differential characteristics in the numeric form and denote the zero difference by ϕ .…”

“…The boomerang attack was initially introduced by Wagner in 1999 for analyzing block ciphers. During the past few years, the boomerang attack has been applied to various hash functions and turned out to be quite fruitful . It has become a common tool for analyzing hash functions.…”