ISC2 SSCP Exam Dumps

In 1973 Bell and LaPadula created the first mathematical model of a multi-level security system.

The following answers are incorrect:

Diffie and Hellman. This is incorrect because Diffie and Hellman was involved with cryptography.

Clark and Wilson. This is incorrect because Bell and LaPadula was the first model. The Clark-Wilson model came later, 1987.

Gasser and Lipner. This is incorrect, it is a distractor. Bell and LaPadula was the first model.

Many times when a connection is opened, the firewall will inspect all layers of the packet. While this inspection is scaled back for subsequent packets to improve performance, this is the best of the four answers.

When packet filtering is used, a packet arrives at the firewall, and it runs through its ACLs to determine whether this packet should be allowed or denied. If the packet is allowed, it is passed on to the destination host, or to another network device, and the packet filtering device forgets about the packet. This is different from stateful inspection, which remembers and keeps track of what packets went where until each particular connection is closed. A stateful firewall is like a nosy neighbor who gets into people's business and conversations. She keeps track of the suspicious cars that come into the neighborhood, who is out of town for the week, and the postman who stays a little too long at the neighbor lady's house. This can be annoying until your house is burglarized. Then you and the police will want to talk to the nosy neighbor, because she knows everything going on in the neighborhood and would be the one most likely to know something unusual happened.

'Inspected at only one Open Systems Interconnetion (OSI) layer' is incorrect. To perform stateful packet inspection, the firewall must consider at least the network and transport layers.

'Decapsulated at all Open Systems Interconnection (OSI) layers' is incorrect. The headers are not stripped ('decapsulated' if there is such a word) and are passed through in their entirety IF the packet is passed.

'Encapsulated at all Open Systems Interconnect (OSI) layers' is incorrect. Encapsulation refers to the adding of a layer's header/trailer to the information received from the above level. This is done when the packet is assembled not at the firewall.

Reference(s) used for this question:

CBK,

p. 466

Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (pp. 632-633). McGraw-Hill. Kindle Edition.

A given message and key always produce the same ciphertext.

The following answers are incorrect:

Repetitive encryption obscures any repeated patterns that may have been present in the plaintext. Is incorrect because with Electronic Code Book a given 64 bit block of plaintext always produces the same ciphertext

Individual characters are encoded by combining output from earlier encryption routines with plaintext. This is incorrect because with Electronic Code Book processing 64 bits at a time until the end of the file was reached. This is a characteristic of Cipher Feedback. Cipher Feedback the ciphertext is run through a key-generating device to create the key for the next block of plaintext.

The previous DES output is used as input. Is incorrect because This is incorrect because with Electronic Code Book processing 64 bits at a time until the end of the file was reached . This is a characteristic of Cipher Block Chaining. Cipher Block Chaining uses the output from the previous block to encrypt the next block.

The Answer: People. The other choices can be strengthened and counted on (For the most part)

The following answers are incorrect:Software. Although software exploits are major threat and cause for concern, people are the weakest point in a security posture. Software can be removed, upgraded or patched to reduce risk.

Communications. Although many attacks from inside and outside an organization use communication methods such as the network infrastructure, this is not the weakest point in a security posture. Communications can be monitored, devices installed or upgraded to reduce risk and react to attack attempts.

Hardware. Hardware components can be a weakness in a security posture, but they are not the weakest link of the choices provided. Access to hardware can be minimized by such measures as installing locks and monitoring access in and out of certain areas.

The following reference(s) were/was used to create this question:

Shon Harris

AIO v.3 P.19, 107-109

ISC2 OIG 2007, p.51-55

A security kernel is defined as the hardware, firmware and software elements of a trusted computing base that implement the reference monitor concept. A reference monitor is a system component that enforces access controls on an object. A protection domain consists of the execution and memory space assigned to each process. The use of protection rings is a scheme that supports multiple protection domains.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 5: Security Architecture and Models (page 194).