D

Symmetric keys provide the fast encryption standards needed by today's applications; however, these keys need a method for exchange over an unsecured network. PKI provides a solution to this challenge.

A and F

Because of its speed, symmetric encryption is a good choice for real-time encryption of bulk data. This speed is achieved because the encryption key is the same as the decryption key.

D and F

The trusted introducer and its clients must trust the root of a system. The root guarantees the identity of the trusted introducer. Only the trusted introducer can guarantee the authenticity of any member of the system.

D

A certificate includes the identity of the issuer of the certificate, the identity of the owner of the certificate, and the public key of the owner.

C and F

Securing enrollment through a PKI can be a sticky situation. The best method is to perform the enrollment over a trusted network (or significantly secured public network). Otherwise, you must manually perform mutual out-of-band authentication between the PKI user and CA.

D

Certificate revocation is needed whenever the private key is not trustworthy anymore. This can occur through a loss of the private key (from a system rebuild or replacement), or a malicious compromise of the private key (from an intruder).

F

The web server certificate is used to authenticate the server to the client and to encrypt the symmetric session keys used for the authentication and encryption of the data stream.

B

The Diffie-Hellman algorithm is commonly used as an automated method to securely exchange symmetric keys over a public network.

A

Asymmetric algorithms use two keys: one public and one private. The public key can be used for encryption and decryption of data and is sent to any requesting host. The private key can be used for encryption and decryption of data and is kept strictly for the sending host.

A

Certificates are not secret information and do not need to be encrypted in any way. The idea is not to hide anything but to ensure the authenticity and integrity of the information contained in the certificate.