Explanation/Reference:
Explanation:
A hub is a device that connects two segments of a single LAN. A hub is a repeater. It provides transparent connectivity to users on all segments of the same LAN. It is a level 1 device.
Incorrect answers:
A. A bridge operates at level 2 of the OSI layer and is used to connect two LANs using different protocols (e.g., joining an ethernet and token network) to form a logical network.
B. A gateway, which is a level 7 device, is used to connect a LAN to a WAN.
C. A LAN is connected with a MAN using a router, which operates in the network layer.

Explanation/Reference:
Explanation:
PKl is the administrative infrastructure for digital certificates and encryption key pairs. The qualities of an acceptable digital signature are: it is unique to the person using it; it is capable of verification; it is under the sole control of the person using it; and it is linked to data in such a manner that if data are changed, the digital signature is invalidated. PKl meets these tests. The Data Encryption Standard (DES) is the most common private key cryptographic system. DES does not address nonrepudiation. A MAC is a cryptographic value calculated by passing an entire message through a cipher system. The sender attaches the MAC before transmission and the receiver recalculates the MAC and compares it to the sent MAC. If the two MACs are not equal, this indicates that the message has been altered during transmission; it has nothing to do with nonrepudiation. A PIN is a type of password, a secret number assigned to an individual that, in conjunction with some other means of identification, serves to verify the authenticity of the individual.

The configuration management process may include automated tools that will provide an automated recording of software release baselines. Should the new release fail, the baseline will provide a point to which to return. The other choices do not provide the processes necessary for establishing software release baselines and are not related to software release baselines.

Explanation/Reference:
Explanation:
Most encrypted transactions use a combination of private keys, public keys, secret keys, hash functions and digital certificates to achieve confidentiality, message integrity and nonrepudiation by either sender or recipient. The recipient uses the sender's public key to decrypt the prehash code into a posthash code, which when equaling the prehash code, verifies the identity of the sender and that the message has not been changed in route; this would provide the greatest assurance. Each sender and recipient has a private key known only to themselves and a public key, which can be known by anyone. Each encryption/ decryption process requires at least one public key and one private key, and both must be from the same party. A single, secret key is used to encrypt the message, because secret key encryption requires less processing power than using public and private keys. A digital certificate, signed by a certificate authority, validates senders' and recipients' public keys.

Section: The process of Auditing Information System