International Association
for Cryptologic Research

We study an infinite class of functions which provably achieve an optimum algebraic immunity, an optimum algebraic degree and a good nonlinearity. We checked that it has also a good behavior against fast algebraic attacks.

The paper discusses the security of hash function with Merkle-Damg{\aa}rd construction and provides the complexity bound of finding a collision and primage of hash function based on the condition probability of compression function $y=F(x,k)$. we make a conclusion that in Merkle-Damma{\aa}rd construction, the requirement of free start collision resistant and free start collision resistant on compression function is not necessary and it is enough if the compression function with properties of fix start collision resistant and fix start preimage resistant. However, the condition probability $P_{Y|X=x}(y)$ and $P_{Y|K=k}(y)$ of compression function $y=F(x,k)$ have much influence on the security of the hash function. The best design of compression function should have properties of that $P_{Y|X=x}(y)$ and $P_{Y|K=k}(y)$ are both uniformly distributed for all $x$ and $k$. At the end of the paper, we discussed the block cipher based hash function, point out among the the 20 schemes, selected by PGV\cite{Re:Preneel} and BPS\cite{Re:JBlack}, the best scheme is block cipher itself, if the block cipher with perfect security and perfect key distribution.