Wallets & Security
Twelve words rebuild the whole wallet. That is the backup and the risk.
When you set up a wallet you receive a list of words — the seed phrase. They look harmless, but they are the master key to your entire wallet. Whoever has them has everything. Whoever loses them may lose everything.
The problem
The device is gone. Rebuild the wallet from nothing.
No phone, no app, no file to copy back. Twelve numbered words on paper, and nothing else in the world. Press Restore and watch what they are actually worth.
The phrase you wrote down
WORDS YOU HAVE 12 / 12The slots stay masked on purpose. What you need is the count and the order — a real phrase is never put on a screen, and never typed into one you did not open yourself.
The wallet app is gone with the device. The words are all that is left. Press Restore.
Nothing came off the old device, because nothing on it was ever needed. Three facts to know cold. Master backup — from these words a compatible wallet rebuilds your entire key structure, on any device. Standardised word list — typically 12 or 24 words from a fixed list, and the order must be exact. Not a password — a password protects an app and can be reset, but the seed is the access.
Ten of twelve is not a backup. The phrase only rebuilds the key structure when it is complete and in the exact order it was written in. And now the restore runs backwards: because nothing but the words was ever needed, nothing but the words can ever be enough. Try the thing everybody tries next.
Myth. With self-custody there is no central party that knows or can replace your seed. Without the seed and without a working device, access is permanently gone. That is exactly why the backup matters so much — and it is the whole asymmetry of this lesson: the same twelve words are the entire backup and the entire risk. Nobody holds a copy for you, which is the same sentence as: nobody can take it from you by asking someone else.
The definition
Three things the restore just proved.
Tap each card for the mechanism underneath it.
Hands on
Five places people are tempted to keep it. One of them is fine.
Pick a spot, read what it actually is, then call it. Marking everything dangerous scores badly — the point is to see why a spot leaks, not to be suspicious of paper.
Choose a spot above, then call it.
One request is the whole tell.
Any site, app or “support” agent that asks you to enter your seed phrase — to verify something, to restore something, to fix anything at all — is an attacker, on that request alone. No wallet, no exchange and no support needs your seed to fix anything, because nobody legitimate ever holds it. Even entering part of it weakens your backup. Close the page and open the official source yourself.
The bridge
Four conditions, and the phrase does its job.
Offline, secret, complete and durably readable is the standard. Here is what each word in that sentence is doing.
That closes the ownership foundation. A wallet is a keychain and an interface — the coins live on the blockchain. A key pair is an address you hand out freely and a private key you never do, with a signature that proves ownership without revealing it. And the seed phrase is the master backup underneath both: stored offline, written exactly, never shared, and with no reset in existence. You now know what you own and what you protect. The next lesson settles the question this one leaves open — who is actually holding the keys, you or somebody else.
Check yourself
Five questions.
Answers come straight from this lesson. Submitting completes it.