What is SHA1?

SHA-1 (Secure Hash Algorithm 1) is a cryptographic hash function designed by the United States National Security Agency and published as a U.S. Federal Information Processing Standard. It produces a 160-bit (20-byte) hash value known as a message digest. SHA-1 was widely used to verify data integrity, especially for software distribution and version control systems (like Git), and in security protocols such as SSL/TLS. However, due to discovered vulnerabilities and collision attacks, SHA-1 is now considered cryptographically broken and has been superseded by stronger hash functions like SHA-256 and SHA-3.