Technical Definition

Signature

A cryptographic signature proves that the holder of a private key authorized specific data without revealing the private key itself.

By Crypto University Editorial
TransactionSecret recovery phraseApproval / Allowance

✦ Key Insight

Signing is how users authorize transfers, swaps, logins, permits, and other actions. A malicious signature request can sometimes grant permissions or enable later actions, so users should understand what they are signing instead of treating every signature as harmless.

✕ Common Misconceptions

"Sign message" does not always mean "no risk." Some signed messages can authorize token permits, orders, or other actions. Check the domain, chain, spender, amounts, expiration, and readable details before signing.

Detailed Explanation

Wallets use digital signatures to authorize blockchain transactions and messages. The signature is mathematically linked to the signed data and the signer's key. Networks or applications can verify it using the corresponding public address or key information.

In Practice

“A wallet asks a user to sign a typed message proving ownership of an address to log in to a dapp. No token transfer occurs, but the signed message can be verified by the application.”

Dig Deeper

Wallet Address

The public string of characters others send crypto to, derived from your public key.

Secret Recovery Phrase

A secret recovery phrase is a sequence of words used by many wallets to derive and restore private keys and accounts.

Approval / Allowance

An ERC-20 approval sets an allowance that lets a specified address or smart contract spend up to a defined amount of a user's tokens.

Transaction

A blockchain transaction is a signed or authorized instruction that changes blockchain state or transfers value when accepted by the network.

Nonce (account)

An account nonce is a sequence value used to order transactions from an account and help prevent the same signed transaction from being replayed repeatedly.