File Decryption

How to use the file decryption

1. Choose the encrypted file, which usually ends in .enc.
2. Enter the password it was encrypted with.
3. Download the recovered file.

About this tool

This opens files encrypted by the companion tool. The salt, starting vector and iteration count all live in the file's header, so a file encrypted on one machine opens on another with nothing but the password — no key file, no account, no shared configuration.

A wrong password and a modified file fail in exactly the same way, and the tool says so rather than guessing. AES-GCM authenticates the ciphertext as well as encrypting it, so both break the same check. That is the behaviour you want — a decryption that quietly succeeded on tampered data would be far more dangerous — but it does mean a failure is not proof that the password was wrong.

A file that was not encrypted here is identified from its header and reported as such, rather than producing a confusing failure several steps later.

Everything happens in this tab. The encrypted file, the password and the recovered contents never leave it, which is the point: a decryption service you upload to is a service that has both the file and the password at the same moment.

Common uses

• Opening a file you encrypted earlier.
• Recovering a document sent to you as an encrypted file.
• Checking that an encrypted backup still opens.

Frequently asked questions

Why does it not say whether my password was wrong?

Because it cannot. AES-GCM authenticates the data, so a wrong password and an altered file fail the same check. Guessing between them would be making something up.

Can it open files from other encryption tools?

No. It reads the header format written by the encryption tool here. Another tool's file is identified and reported rather than failing obscurely.

Is the file uploaded to decrypt it?

No, and that is the point — an upload would put the file and the password on someone else's machine at the same moment.