What Is a Digital Signature?
In Bitcoin, a digital signature is a mathematical proof that a transaction has been authorized by the owner of the funds. It is created using a private key and is included in every transaction broadcast to the network.
How It Works
When you send bitcoin from your wallet, it uses your private key to "sign" the transaction details. This signature is unique to that specific transaction and cannot be forged without the private key.
Proving Ownership
The network can verify this signature using your public key. This allows you to prove you own the funds and authorize the payment without ever revealing your private key.
Ensuring Integrity
A digital signature also ensures that the transaction has not been altered after it was signed. Any change to the transaction details would invalidate the signature, protecting against tampering.
The Key to Security
Digital signatures are a cornerstone of Bitcoin's security model. They are what allow you to have full control over your funds in a decentralized system, making every transaction secure and verifiable by the entire network.