Blockchain authorization is a permission or cryptographic signature that allows a transaction or smart contract action to proceed. Depending on the system, it may be provided by a wallet owner, a delegated key, or an approval process involving several signers. Authorization is distinct from broadcasting a transaction: it establishes that the action has been approved, while the network then checks and processes it.
In cyber security, authorization controls help prevent unauthorized transfers and contract operations. Attackers may target private keys, trick users into signing harmful transactions, or compromise systems that prepare or approve transactions. Defenses include protecting signing keys, limiting their permissions, separating signing systems from developer environments, and requiring independent review for sensitive actions. Monitoring unusual approvals can help detect abuse before or after a transaction is submitted.