Which key is used to decrypt a message that has been

Solution

In asymmetric encryption, the recipient's public key is used by the sender to encrypt the message. The recipient’s private key, which is kept secret, is used to decrypt the message. This ensures that only the recipient, who possesses the private key, can read the encrypted message, providing confidentiality. Option A (Sender's public key) is incorrect because the sender’s public key is not used for decryption. Option B (Recipient's public key) is incorrect because the public key is used for encryption, not decryption. Option C (Sender's private key) is incorrect because the sender's private key is used to sign the message, not to decrypt it. Option E (Symmetric key) is incorrect because symmetric keys are used in symmetric encryption, where the same key is used for both encryption and decryption.