What is a Hash Function?
A cryptographic hash function is an algorithm that takes an input (or 'message') and returns a fixed-size string of bytes. The output matches the input deterministically but is practically impossible to reverse.
Common Uses for Hashes
- Password Storage: Websites store the hash of your password, not the password itself, for security.
- Data Integrity: File downloads often provide a checksum (hash) so users can verify the file wasn't corrupted or tampered with.
- Digital Signatures: Essential for blockchain and secure communications.
Supported Algorithms
- SHA-256: Part of the SHA-2 family. Highly secure and widely used (e.g., in Bitcoin).
- SHA-512: A 512-bit hash function providing even stronger security for 64-bit systems.
- SHA-1: A legacy algorithm. It is no longer considered secure against collision attacks but is still used for non-security checksums.