Digital Signatures and Cryptography

A digital signature is primarily a cryptographic mechanism used for authentication and non-repudiation of electronic documents. Statement 1 is partially correct but not the primary definition - a digital signature is issued by the signer (using a private key), not by the certifying authority itself, though the authority may certify the public key. Statement 2 is correct: digital signatures serve as proof of identity and authenticity, allowing individuals to access secure systems. Statement 3 is correct: digital signatures provide both authentication (verifying identity) and integrity (ensuring the document has not been altered). A digital signature involves applying a hash algorithm to create a digest, then encrypting this with the private key. > Digital signature = Authentication + Integrity verification using asymmetric cryptography. Answer: b.