Text Encryption

How to use the text encryption

1. Paste your text and choose a long passphrase.
2. Encrypt, then copy the payload.
3. Share the password through a different channel from the payload.

About this tool

AES-256 in GCM mode, with the key derived from your password by PBKDF2 at 310,000 iterations. Three choices here matter, and getting any of them wrong produces something that looks encrypted and is not secure.

A fresh random salt is generated for every encryption, so the same password never derives the same key twice. A fresh random IV is generated too — reusing an IV with GCM is catastrophic rather than merely untidy, as it leaks the relationship between the two plaintexts and can expose the authentication key itself. Both are stored alongside the ciphertext, so the payload is self-contained and the password is all you need to decrypt it.

GCM rather than CBC means decryption fails loudly on altered data instead of returning plausible rubbish. When decryption fails, the message says the password may be wrong or the data may have been altered, and does not guess which — authenticated encryption genuinely cannot distinguish the two, and pretending otherwise would be a lie about how it works.

What this is good for: sending something sensitive over a channel you do not trust, when the recipient can be given the password separately. What it is not: a substitute for a password manager, or for end-to-end encrypted messaging, both of which handle key exchange properly. The weakest part of this scheme is always the password and how you share it.

If you lose the password, the text is gone. There is no recovery, and that is the point rather than an oversight.

Common uses

• Sending sensitive notes over a channel you do not control.
• Storing a secret in a place you do not fully trust.
• Learning how authenticated encryption behaves.

Frequently asked questions

What happens if I lose the password?

The text is unrecoverable. There is no backdoor and no reset — that is what makes the encryption worth anything.

Why does encrypting the same text twice give different output?

A fresh random salt and IV are generated each time. Identical output from identical input would leak that the two messages are the same.

Is my text or password uploaded?

No. Everything happens in the page through the browser's own crypto, and the password is never stored anywhere.

Should I use this instead of a password manager?

No. A password manager handles storage, key management and sharing properly. This is for sending something over an untrusted channel when you can share the password separately.