1. Your wallet signs the transaction
When you send bitcoin, your wallet builds a message — these coins, to this address, with this fee — and signs it with your private key. The digital signature proves you control the coins without revealing the key itself.
2. It is broadcast to the network
The signed transaction goes to a few Bitcoin nodes. Each one checks the signature and that the coins haven't already been spent, then passes it on. Within seconds it has reached thousands of independent computers. No company runs this; everyone checks.
3. It waits in the mempool
Valid transactions wait in each node's mempool until a miner includes them in a block. Blocks have limited space, so miners prefer transactions that pay more per byte (sat/vB). When the network is busy, fees rise; a low-fee transaction can wait hours or days.
4. A miner puts it in a block
Miners assemble waiting transactions into a candidate block and repeatedly hash it with a changing number until the result is below the network's target. It is pure trial and error — the whole network finds one block about every ten minutes. The winner broadcasts the block and earns the block reward plus all its fees.
5. Confirmations
Once your transaction is in a block it has one confirmation. Each block mined on top adds another and makes reversing it exponentially harder, because an attacker would have to redo all that work faster than the rest of the network. Six confirmations — about an hour — is the common rule for large amounts.
6. The coins arrive
The recipient's wallet sees the transaction, first as pending and then confirmed. Nothing physically moved: the shared ledger now records that those coins can be spent by a different key.
Why it is secure
- Signatures: only the private key can authorise spending.
- Everyone verifies: every node independently checks every rule.
- Proof of work: rewriting history means out-mining the entire network.
- No single point of failure: thousands of copies of the ledger worldwide.
Questions people ask
How long does a Bitcoin transaction take?
A block is found about every ten minutes, so the first confirmation usually takes 10 minutes to an hour depending on the fee. Six confirmations takes about an hour.
What is a Bitcoin confirmation?
A block added to the chain after the block containing your transaction. More confirmations make it harder to reverse.
Why are Bitcoin fees sometimes high?
Block space is limited. When many people are sending at once, they bid against each other with higher fees per byte to get included sooner.
What do Bitcoin miners actually do?
They bundle transactions into blocks and race to find a hash below the network target. The winner adds the block and is paid new bitcoin plus fees.