True or false. Keyless algorithms are deterministic functions that have certain properties that are useful for cryptography.

True.

1. Keyless Algorithms: These are algorithms that do not require a key to function. They operate solely based on the input data and the algorithm's internal logic.

2. Deterministic Functions: A deterministic function will always produce the same output given the same input. This is a crucial property for cryptographic algorithms to ensure consistency and reliability.

3. Properties Useful for Cryptography:

   • Hash Functions: One of the primary examples of keyless algorithms in cryptography. They take an input (or 'message') and return a fixed-size string of bytes. The output is typically a 'digest' that is unique to each unique input.
   • Collision Resistance: It should be hard to find two different inputs that produce the same output.
   • Pre-image Resistance: Given an output, it should be hard to find the input that maps to that output.
   • Second Pre-image Resistance: Given an input and its output, it should be hard to find a different input that produces the same output.

These properties make keyless algorithms, particularly hash functions, extremely useful in various cryptographic applications such as digital signatures, data integrity verification, and password hashing.