What is Private key?
The secret number that authorises spending from an address. Whoever holds it controls the coins, unconditionally.
A private key is a 256-bit number. The corresponding public key and address are derived from it one-way, so publishing an address reveals nothing about the key.
There is no recovery mechanism. This is the whole point — nobody can seize or reverse what only you can authorise — and the whole risk.
Related terms
Public key
The value derived from a private key that lets anyone verify a signature without learning the key itself.
Keys & custodySeed phrase
Twelve or twenty-four words from which every key in a wallet is derived. Anyone with the words has the coins.
Keys & custodySelf-custody
Holding your own private keys rather than trusting a third party to hold coins for you.
Keys & custodyAddress
A string encoding the conditions under which an output can be spent. Bitcoin's equivalent of an account…
This definition is part of the Bitcoin Logical glossary. For the fuller explanation, start with Aprender, or see the live numbers on O Sinal Bitcoin.