In this lesson
- understand what a passphrase does to a seed phrase
- find out what it protects against and what new trap it brings
- decide whether you need one at all
Imagine a house where the front door key opens a living room with a few trinkets. The real safe, though, is behind a secret door in the bookshelf – and only a password you know opens it. That is exactly how a passphrase works.
What a passphrase does#
A so-called passphrase is an optional password added to the seed phrase. The BIP39 standard allows it and most hardware wallets support it. It is also called the "25th word", although it can be any text.
- Seed phrase + passphrase = a completely different wallet. Different keys, different addresses.
- Every passphrase opens a different wallet – even one with a typo.
- The wallet never says "wrong password". It simply shows a different, most likely empty, wallet.
What it protects against#
- Someone who finds your seed phrase backup. Without the passphrase they cannot reach the main money.
- A physical attack on the device. Even if someone extracted the seed phrase from an older wallet, the passphrase is not stored in the device.
- Extortion – partly. Some people leave a small amount in the wallet without a passphrase as a decoy. It may help, but do not rely on it.
A new trap: forgetting#
Nobody can recover a passphrase. If you forget it or make a typo and do not know which, the money is gone – just as if you lost the seed phrase. So:
- Back it up separately, in a different place from the seed phrase. Whoever finds one does not have the other.
- Watch upper and lower case, spaces and accents. "Cat" and "cat" are two different wallets.
- Test a recovery with both the seed phrase and the passphrase before sending your savings.
- Think of your heirs. Without the passphrase, they cannot reach the money either.
Do you need one?#
| Situation | Recommendation |
|---|---|
| you are starting out, smaller amounts | not yet – first master backing up the seed phrase |
| larger savings, you can back up carefully | makes sense |
| worry that someone finds the backup or steals the device | makes sense |
A passphrase raises security and the risk of loss
With a passphrase you have two things to keep. Losing either of them means losing the money. Add one only when your backup is well thought out and tested.
Common myths#
- "I entered my passphrase and the wallet is empty – I have been robbed." More likely you entered a different passphrase, perhaps with a typo.
- "I will write the passphrase on the same paper as the seed phrase." Then it protects nothing at all.
- "The longer and more complex, the better." Only if you back it up reliably. An unmemorable passphrase without a backup is a time bomb.
Summary
- A passphrase is an optional password for the seed phrase; every passphrase opens a different wallet.
- It protects against someone finding your backup and against physical attacks on the device.
- Nobody can recover it and the wallet does not report mistakes – back it up separately and test a recovery.
- For beginners with smaller amounts it is not necessary yet.