Sign with Fountain

Fountain is the free SignBit signing app for Windows, macOS, Linux, and Android. It holds your keys and signs completely offline; it never makes a network call.

1. Install Fountain

Download it from the SignBit download page and check the SHA-256 checksum shown there against the file you got. From version 0.6.4 the Windows build is signed by SignBit Ltd, and Windows shows that name as the publisher when it runs. On Android you can also install Fountain from Google Play, which keeps it up to date.

2. Create or import a key

Set a passphrase, then create a new key or import an existing 24-word phrase. Fountain generates keys to the exact specification SignBit vaults use.

3. Write down the 24 words

On paper. Not a photo, not a password manager, not a text file. If you forget your Fountain passphrase, those words are the only way back to the key, because nobody, SignBit included, can decrypt the keystore without it.

4. Export the public key and enroll it

Fountain exports the account public key and fingerprint. That is all SignBit needs and all it ever receives. Enroll it in your vault.

5. Sign a transaction

Move the transaction into Fountain by copy and paste, by file, or by QR code. Fountain shows you the outputs, the amounts, and the fee, worked out from the transaction itself, not from anything we told it. Sign, then carry the result back the same way.