Bob and Kevin are both using crypto to communicate with other people. Bob doesn't want Kevin eavesdropping on his messages, and vice versa. They each need to choose algorithms and keys. Which of the following choices will protect one from eavesdropping by the other? Select all that apply.

A. Use the same algorithm and the same key.
B. Use different algorithms and the same key.
C. Use the same algorithm and different keys.
D. Use different algorithms and different keys.