How Bitcoin Transactions Work
From wallet broadcast to network confirmation—what happens when you send Bitcoin.
Bitcoin Basics
Public and Private Keys
How cryptographic keys prove ownership and authorize every Bitcoin transfer.
Overview
A private key is a secret number that lets you spend Bitcoin. A public key and its derived address are safe to share—they are where others send funds. Wallets manage these keys for you, but the security model always comes back to keeping the private key confidential.
If someone obtains your private key or recovery phrase, they can move your Bitcoin. There is no password reset on the blockchain. Back up keys offline and never share them, even with someone claiming to be support staff.
Keys and addresses explained
Your private key is a large random number. From it, wallets derive a public key and receiving addresses. You can share addresses freely; they function like deposit instructions, not account passwords.
Signing a transaction proves you authorize spending without revealing the private key. Elliptic curve cryptography lets strangers on the internet agree you had permission to move funds.
Where wallets fit in
Wallet software generates keys, stores them securely, scans the chain for payments, and constructs outgoing transactions. The wallet is an interface; the keys are the actual control mechanism.
Different wallets use different backup formats, but BIP39 seed phrases are the most common recovery method today. Treat the phrase like the master key it is.
Common mistakes to avoid
Never enter a seed phrase into a website, chat message, or remote-support tool. Phishing pages often mimic wallet brands to harvest phrases.
Storing keys only on one phone with no backup is another frequent failure mode. Redundant offline backups in separate secure locations are boring insurance against device loss.
