Open dbosk opened 2 years ago
Particularly that collision resistance implies second preimage resistance, which in turn also implies preimage resistance.
The reductions are something along the lines of this:
col(): x <- rand(), x' <- second_pre(x)
second_pre(x): y <- H(x), do x' <- pre(y) until x' != x
It's actually a bit more complicated when looking at the details, I can recommend reading "Cryptographic Hash-Function Basics: Definitions, Implications, and Separations for Preimage Resistance, Second-Preimage Resistance, and Collision Resistance" by Rogaway and Shrimpton. They cover the details very nicely.
Particularly that collision resistance implies second preimage resistance, which in turn also implies preimage resistance.
The reductions are something along the lines of this:
col(): x <- rand(), x' <- second_pre(x)second_pre(x): y <- H(x), do x' <- pre(y) until x' != xIt's actually a bit more complicated when looking at the details, I can recommend reading "Cryptographic Hash-Function Basics: Definitions, Implications, and Separations for Preimage Resistance, Second-Preimage Resistance, and Collision Resistance" by Rogaway and Shrimpton. They cover the details very nicely.