Your organization has recently decided to implement encryption on the network. Management requests that you implement a system that uses a private or secret key that must remain secret between the two parties. Which system should you implement?
a. running key cipher
b. concealment cipher
c. asymmetric algorithm
d. symmetric algorithm
Answer: D. Explanation: A symmetric algorithm uses a private or secret key that must remain secret between the two parties. A running key cipher uses a physical component, usually a book, to provide the polyalphabetic characters. A concealment cipher occurs when plaintext is interspersed somewhere within other written material. An asymmetric algorithm uses both a public key and a private or secret key.