What does SHA stand for in cryptography?

SHA stands for Secure Hash Algorithm, which is a family of cryptographic hash functions designed by the National Security Agency (NSA). These hash functions are fundamental in ensuring data integrity and security across various applications, including digital signatures, certificate verification, and password hashing.

The term "Secure" indicates that the algorithm is designed to produce a unique hash value for each unique input, making it difficult for attackers to produce the same output (collision resistance), reverse-engineer the original input (pre-image resistance), or find two different inputs that produce the same output (second pre-image resistance).

The different versions of SHA, such as SHA-1, SHA-256, and SHA-3, each offer varying levels of security and performance, and are widely used in modern cryptographic systems to enhance data security.