Glossary · Custody & Security
Private Key
Also: private keys, signing key
Published
Private Key — A private key is the secret number that authorizes transactions from a blockchain address by producing a digital signature that the network verifies against the address's public key. Whoever can use the private key controls the assets at that address, which makes key management the foundation of digital asset custody.
Keys and Control
Blockchains do not have accounts with owners; they have addresses with rules. For most addresses the rule is a single public key, and the matching private key is the only thing that can satisfy it. There is no recovery process at the network level. A lost key is lost funds, and a stolen key is stolen funds, which is why institutional custody exists as a discipline.
Generating and Protecting Keys
Institutional programs generate keys in controlled environments, often inside hardware security modules or through a multi-party computation ceremony that never creates the complete key at all. Backups are split and stored in separate secured locations. Access to signing is governed by policy: who can initiate, who must approve, which destinations are allowed, and what limits apply.
From Keys to Controls
A well-run custody program makes the key itself uninteresting. Distributed signing through MPC or multisig, tiered storage, and approval workflows mean that no individual, device, or location can move funds alone, and audits confirm that the controls operate as designed.