Which of the following is a primary reason for using digital signatures in modern cryptography? 

Digital signatures provide both authentication and integrity in modern cryptography. A digital signature uses asymmetric cryptography, where the sender signs a message with their private key. The recipient can then verify the signature using the sender's public key. This ensures that the message was indeed sent by the claimed sender (authentication) and that it was not tampered with during transmission (integrity). Digital signatures are essential for securing sensitive communications in many applications, including email, financial transactions, and software distribution. Why Other Options are Incorrect: A) To encrypt the message content: Encryption ensures confidentiality, but it is not the primary function of digital signatures. C) To generate symmetric keys: Digital signatures do not generate keys; they authenticate and ensure message integrity. D) To establish a secure communication channel: Digital signatures authenticate messages but do not establish secure channels. Protocols like TLS are used for secure channels. E) To store sensitive data securely: Digital signatures are not used for data storage but for verifying the authenticity and integrity of transmitted messages.