Digital Signature

A digital signature is a cryptographic mechanism that allows one party to prove that specific data was signed using the corresponding private key and that the signed data has not been modified.

A typical scheme uses a key pair. The private key remains secret, while the public key is available for verification. The signer creates a signature using the private key, and other participants can verify it using the public key.

In blockchains, digital signatures are fundamental to the authorization of many transactions. A wallet creates the transaction data, signs it, and the network verifies the signature before accepting the transaction.

A signature does not hide the transaction contents. Authorization, integrity, and confidentiality are separate properties. A digital signature establishes authorship and protects against undetected modification of signed data, but it does not automatically make the data private.

Signature security

Digital-signature security depends on the cryptographic algorithm, implementation, and protection of the private key. If an attacker obtains the private key, they may be able to create signatures that the network considers valid.

Digital signatures are therefore closely connected to private-key security, hardware wallets, and transaction signing.