Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Difficulty of finding two different inputs that hash to the same value

Collision resistance is a security property of cryptographic hash functions. A hash function $H$ is said to be collision resistant if it is computationally infeasible to find two input strings $s$ and $s'$ such that $s' \ne s$ but $H(s') = H(s)$.

Collision resistance is one of the strongest security properties usually demanded of hash functions: a collision resistant hash function is automatically also first and second preimage resistant.

See also: ,

history | excerpt history