Secure Hash Algorithm (SHA)

The Secure Hash Algorithm (SHA) is a family of cryptographic functions designed to ensure data integrity. It takes an input (or message) and produces a fixed-size string of characters, which is a unique representation of that input, known as a hash. Even small changes to the input result in a dramatically different hash. This process helps verify that data hasn't been altered, as any change in the original data will lead to a different hash value. SHA is commonly used in digital signatures, certificates, and various security protocols to protect information online.