Digital Signature

A cryptographic mechanism that verifies the authenticity and integrity of a digital document or message using a private-public key pair.

What is Digital Signature?

A digital signature is a cryptographic technique used to validate the authenticity and integrity of a digital document, message, or transaction. It is generated by a user with their private key, creating a unique string of data that can be verified by anyone with the corresponding public key. This process ensures two key properties: (1) the signature confirms that the document was created by the owner of the private key, proving authorship, and (2) it verifies that the document has not been altered since it was signed, ensuring integrity. Digital signatures are widely used in blockchain and digital asset transactions to secure and validate operations.

The process typically involves hashing the document to create a fixed-length string, which is then encrypted with the signer’s private key to produce the digital signature. The recipient can use the signer’s public key to decrypt the signature, rehash the document, and compare the two hashes to confirm authenticity and integrity. Common algorithms for digital signatures include RSA, ECDSA (used in Bitcoin and Ethereum), and EdDSA.

Digital signatures are critical for trust in decentralized systems, such as signing transactions on Ethereum or Bitcoin networks, where they ensure that only the rightful owner can authorize transfers of digital assets. They provide security without requiring intermediaries, making them essential for smart contracts, legal agreements, and secure communications.