What Is the Role of a Digital Signature in a Bitcoin Transaction?

A digital signature proves ownership of the funds being spent without revealing the private key. It is created using the sender's private key and is attached to the transaction data.

Miners verify this signature using the sender's public key, which is derived from the private key. A valid signature confirms the transaction was authorized by the owner of the UTXO.

This cryptographic proof is essential for transaction security and immutability.