Bitcoin (blockchain signatures)

Bitcoin uses digital signatures to ensure secure, verifiable transactions. When someone sends Bitcoin, they sign the transaction with their private key, which proves they own the funds. This signature is unique and cannot be forged without the private key. The network and others can verify this signature using the sender’s public key, confirming the transaction's authenticity and integrity. This process prevents fraud and double-spending, enabling trustless transfers directly between users without needing a third party. Essentially, blockchain signatures serve as secure, digital proof of ownership and consent in Bitcoin transactions.