The Digital Signature Algorithm (DSA) is a widely used method for creating digital signatures, which verify the authenticity and integrity of digital messages or documents. Developed by the National Institute of Standards and Technology (NIST) in the 1990s, DSA relies on mathematical principles of modular arithmetic and prime factorization to generate a unique signature for each message. DSA works by using a pair of keys: a private key for signing and a public key for verification. When a sender signs a message with their private key, the recipient can use the sender's public key to confirm that the signature is valid, ensuring that the message has not been altered and is indeed from the claimed sender.