Secure Hash Generator (SHG) is a free, lightweight, easy-to-use utility that is able to generate SHA-256 hashes from any input string or file, regardless of its format (PDF, DOC, XLS, MP3, FLAC, WAV, or other file types).

The SHA-256 checksum is a secure, 128-bit hashing algorithm developed by the National Security Agency (NSA). The SHA-256 checksum is used in many secure cryptographic applications, including the military block cipher AES, the TLS connection authentication mechanism in OpenSSL, and the X.509 certificate authentication mechanism in the popular OpenSSL web server.

The SHA-256 checksum algorithm is fast and its outputs are large enough to not be affected by the limited size of internal hashing hardware registers.