Wallets & Security
A wallet holds no coins. It holds the access to them.
Your phone, with the wallet app on it, falls into the sea. Are your coins gone? The answer decides whether you have understood crypto — and it tells you exactly what there is to protect.
The problem
The phone is the wallet. Destroy it.
Three presses. Do not stop after the second one — the third is where the real risk lives.
One device, one shared register
ILLUSTRATIVEInstalled, open, showing you a number.
Every participant keeps these entries. The figures are illustrative; where the entries live is the point.
Coins lost when the device died: — · Coins lost without the backup: —
The phone is working and the balance is on the screen. Press Break the device.
Coins exist as entries on the blockchain — the network's shared register. The wallet stores the access credentials that let you control those entries, so it is a keychain, not a vault. Destroying the device destroyed a screen and a set of keys sitting on it. It did not destroy anything the network is keeping.
So the device was never the thing at risk. The access was. With a correct backup you restore that access on a new device and carry on; without it the entry is simply frozen where it stands, in public, for good — nobody is holding a copy of your keys to hand back to you. How that backup works is Lesson 3, and it is the single most important hour in this section.
The definition
Three claims that follow from that.
Tap each card for what it actually means in practice.
Hands on
Whose job is it?
A wallet has three jobs — the network does the rest. Tap each task and sort it: the wallet's, or the blockchain's?
Show your balances in a readable way
THE WALLETThree jobs, and that is it — the wallet is your interface. The register itself, and the verification of every transaction, stays in the network.
The bridge
What the wallet does, and where it stops.
Three jobs on your side of the line, and one large one on the other.
Wallet = keychain. Blockchain = register. Backup = lifeline. Everything in this section hangs off that one sentence — and the next lesson opens the keychain itself: the two keys that carry the whole system, one of which you hand out freely and one of which never leaves your device.
Check yourself
Five questions.
Answers come straight from this lesson. Submitting completes it.