What is a cryptographic hash?
A hash function is a mathematical algorithm that turns data of any length into a fixed-length string (a digest). The key properties of a cryptographic hash are that you cannot recover the original text from the hash value (it is a one-way function) and the avalanche effect (changing even a single character of the input completely changes the hash). Note that MD5 and SHA-1 are no longer considered collision-resistant and should not be used for security purposes.
Where SHA-256 is used:
- Verifying the integrity of downloaded installers and ISO images.
- Bitcoin network consensus (Proof-of-Work).
- Digital signatures and SSL/TLS certificates.
- Salted password hashing in databases (ideally via a dedicated KDF such as bcrypt or Argon2).
Privacy and security:
This generator uses the native window.crypto.subtle interface built into all modern browsers (Chromium, Safari, Firefox) for SHA hashes, and a local JavaScript implementation for MD5. Your data never leaves your computer’s memory.