What is a digital signature and how does it work?
D5 · Crypto · CompTIA Security+ SY0-701A digital signature proves both integrity and non-repudiation. The sender hashes the message, then encrypts that hash with their private key. The recipient decrypts the hash using the sender's public key and compares it to their own hash of the message.
Encryption uses the recipient's public key (for confidentiality). Signing uses the sender's private key (for authentication + non-repudiation). Don't mix these up on the exam.