128 bits are 2^48 (~2.81*10^14) times larger than 80 bits (80 bits is the brute force, and SHAttered was less than that), and comparing SHA-2 to a Mersenne Twis

128 bits are 2^48 (~2.81*10^14) times larger than 80 bits (80 bits is the brute force, and SHAttered was less than that), and comparing SHA-2 to a Mersenne Twister is just picking two numbers and saying "this one is less than that one" without context. EDIT: "The computational effort spent on our attack is estimated to be equivalent to 2^63.1 SHA-1 calls" [1] Comparing that to 2^128 (birthday paradox SHA-256) is... It doesn't apply. [1] http://shattered.it/static/shattered.pdf http://shattered.it/static/shattered.pdf