Which statement is true regarding a session key in the Diffie-Hellman key-exchange process?
A.
A session key value is exchanged across the network.
B.
A session key never passes across the network.
C.
A session key is used as the key for asymmetric data encryption.
D.
A session key is used as the key for symmetric data encryption.
Why the correct answer is B?
According JNCIS-SEC Study Guide-Part 1 answer D is also suitable:
“The DH Key Exchange Process
Using the same DH group, each Junos security platform creates unique public and private keys. These keys are mathematically related by means of the DH algorithm.
The public key values exchange across the network. Each peer then runs its local private key and the received public
key value through the DH algorithm to compute a common session key.
The session key itself never passes across the network.
The session key is then used as the key for symmetric data encryption.”
i think the its d
Each side can calculates session key from exchanging information between peer. SO,that why session key itself never passes across the network.
A DEK is used for data encryption which is produced from the secret key, the secret key itself, a Key Encryption Key, is by its nature of production, asymmetric, having derived from each sides application of their private key to the exchanged public key.
3DES is a likely choice although could also be AES for producing the symmetric DEK.
Choice D. A session key is used as the key for symmetric data encryption. — is poorly worded in that the session,i.e., the secret key, is used with a symmetric algorithm to produce the final key needed for secure transfer of data.
I have the same idea. B