Public key cryptography is so-named because: a. It is highly popular b. Its use is not restricted by patents c. It utilizes an open source encryption algorithm d. The key that is used to encrypt a...

Public key cryptography is so-named because:

a. It is highly popular

b. Its use is not restricted by patents

c. It utilizes an open source encryption algorithm

d. The key that is used to encrypt a message does not need to be kept a secret but can be made public

Two parties wish to exchange encrypted messages using symmetric key cryptography. The parties do not have an out-of-band method for exchanging keys. The parties should use:

a. A stream cipher

b. Message digests

c. Public key cryptography

d. Diffie-Hellman key exchange