CISSP Question of the Week: Asymmetric Encryption

The correct answer is C.

A private key is used to decrypt a file that uses asymmetric encryption. In asymmetric encryption, which is sometimes referred to as public key encryption, a user creates a public key and a private key pair. The user distributes the public key and retains the private key. Another user can then use the distributed public key to encrypt a file before sending that file to the owner of the private key. The owner then uses the private key to decrypt the received file. If a hacker wants to decrypt a file that was encrypted with a user’s public key, then the hacker must gain access to or fabricate a replacement for the private key.

A message digest, which is created by a hashing algorithm, can be used to determine whether a file has been modified subsequent to the creation of the file’s message digest. Plaintext refers to unencrypted files.