What is a cryptographic hash function?

A cryptographic hash function is a mathematical algorithm that converts input data into a fixed-size string of characters, typically a hash value. Key properties include:

1. **Deterministic:** Same input always produces the same hash value.

2. **Fixed Size:** Produces a hash value of consistent length regardless of the input size.

3. **Fast Computation:** Efficiently computes hash values for any input.

4. **Pre-image Resistance:** Difficult to reverse-engineer the original input from the hash value.

5. **Collision Resistance:** Hard to find two different inputs that produce the same hash value.

Cryptographic hash functions are widely used in data integrity checks, digital signatures, and password hashing.