question about encryption

[Timber Lee]

QUESTION :
Which can be used for encryption?
POSSIBLE ANSWERS:
* X.509
* Private key
* Public key (CORRECT)
* Session key (CORRECT)
* Digital certificate
* Message Digest
why is private key not a correct answer?
what is defferent between public key and session key?

[Ricardo Polero Baraldi]

Hi,
QUESTION :
Which can be used for encryption?
POSSIBLE ANSWERS:
* X.509
* Private key
* Public key (CORRECT)
* Session key (CORRECT)
* Digital certificate
* Message Digest
why is private key not a correct answer?
what is defferent between public key and session key?
You will use a Public Key for "check" if the message and not for crypt !
Session key encript the message and is used for SSL fr example. The Public key and the private key are mathematic and mutual depended and if used for ASYNCRO crypt and session is for SYNCRO crypt
Hope this help