Need help with this Encryption Homework assignment.

Category of cipher often requires the use of a certification authority to secure? Asymmetric Encryption Symmetric Encryption Hill Cipher Message Authentication Code What is meant by the term "negotiability in regard to information security? The ability to prove possession of a right or privilege The ability to hide sensitive data from others The ability to prevent others from wrongly claiming they were not involved in a transaction The ability to agree to terms with a competing party Which of the following is true? Data origin authentication is used for connection-oriented communications to verify the participants Peer-entity authentication verifies that the other communicant is who he or she claims. Peer-entity authentication is used to verify the physical origin of a data block Using data origin authentication, I can prove to my friend Esmerelda that she's talking with me and not her evil ex Ivan