Private Key
A long secret number that authorizes transactions from a wallet — anyone who has it can spend the funds it controls.
A private key is a cryptographic secret — a 256-bit number — that signs transactions on a blockchain. Your wallet derives a public address from it; the public address is visible to everyone, but only the private key can move the funds.
Losing it is losing everything
There is no password reset on a public blockchain. If you lose your private key, the coins are gone forever. If someone else obtains it, they can drain your wallet instantly. This is why key management is the single most important security habit in crypto.
Key derivation
Modern wallets use one seed phrase to generate thousands of private keys, so a single 12- or 24-word backup protects your whole wallet. Never share a private key or seed phrase with anyone — no legitimate service will ever ask for it.
Related terms
Wallet, Seed Phrase, Self-Custody, Hash, Cryptography