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File & Text Encryption

Encrypt and decrypt text or files with a password using AES-256. Everything happens in this browser; your text, files and password are never sent to a server.

Encryption and decryption use this browser's Web Crypto only. Your text, files and password are not sent or stored. If you forget the password, nobody can recover the data.

How it is protected

  • AES-256-GCM encryption. GCM also detects changes, so a tampered file or a wrong password makes decryption fail.
  • The key is derived from the password with PBKDF2-SHA256 (600,000 rounds). A fresh salt and iv are used every time, so encrypting the same data twice gives different results.
  • The file name is stored inside the ciphertext and is not visible from outside. The output file is the original name + .mnc.
  • A weak password cannot be rescued by the iteration count. Use a random string of 12+ characters (see the password generator).
  • This format (MNC1) is specific to this tool and is not compatible with other programs such as 7-Zip or GPG.

FAQ

What if I forget the password?

It cannot be recovered. Nothing is stored on a server, and the data cannot be decrypted without the password by design.

Can I encrypt large files?

Files are processed whole in memory, so the limit is 100 MB. For bigger files use your archiver's encryption or GPG.

Can I send the result text through a messenger?

Yes. It is plain Base64 (letters and digits) and pastes anywhere. Send the password through a different channel.