Your steel carries 24 completely different words
Your steel does not carry your real seed phrase but an encrypted result: again 24 valid BIP39 words — just entirely different ones. Anyone who finds your backup and types those words into a wallet ends up in an empty wallet. No usable seed, no balance, no indication that the backup contains an encrypted seed. And that's it: the metal holds only these 24 words — no long codes, no extra data. All cryptographic parameters needed for decryption live in your certificate file — it contains no seed words and no ciphertext. Only someone holding both the steel backup and the matching certificate file can recover the real seed phrase.
That means you can take your backup anywhere, travel with it, leave it out in the open at home or store it with family. Only whoever holds both — the steel and a valid certificate file — can decrypt it: the file provides the passphrase that turns the words on the steel back into your real 24 words.
Your seed is never entered online
Your real seed phrase is never entered online — not when setting up the backup and not when restoring it. All encryption and decryption runs fully offline on your own device inside the Secure Element. There is no server, no cloud and no third party that ever sees your real words. The protected process (Intellectual Property Protected) ensures that only the encrypted words go on the steel and the certificate file stays offline on your device.
Certificate file — no seed, nothing to decrypt
The certificate file contains no seed words and no ciphertext. It holds only the cryptographic parameters needed to derive the key and verify the backup — the key, the non-secret derivation value (salt) and the authentication tag. Without the steel nothing can be decrypted with it, because the ciphertext lives on the metal alone. That is why you may safely store it online: in the cloud, in your mailbox, on your phone. Only the certificate file plus the metal seed together yield your real seed phrase.
Plausible decoy seed
The ciphertext is itself a valid 24-word phrase with a correct checksum. A finder sees a normal wallet — and it is empty. They cannot even tell that anything was encrypted.
Passphrase from the certificate file
You generate a digital certificate file and keep it on your computer, phone or USB stick. The passphrase is derived from it — nothing to memorise, nothing to write down, no biometrics. The file contains no seed material and cannot be decrypted; it can be stored online safely and copied as often as you like.
Offline, without servers
Encryption and decryption run fully offline on your device inside the secure element. No server, no cloud, no third party ever sees your real words. Nothing is stored on the device that isn't already on the steel.
How it works
01
Generate the seed
Your wallet creates the real 24 words — offline.
02
Create the certificate file
You generate a digital certificate file and store it on your computer, phone or USB stick.
03
Derive the key
Argon2id derives the AES key from the certificate file — nothing has to be memorised.
04
Encrypt
The passphrase encrypts the seed phrase with AES-256-GCM + Argon2id and maps it to 24 valid BIP39 words.
05
Apply to steel
Only those decoy words go onto the stainless steel.
The world's only available encrypted backup