- (Topic 5)
Which of the following statements pertaining to message digests is incorrect?
Correct Answer:
C
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 4: Cryptography (page 160).
- (Topic 4)
Notifying the appropriate parties to take action in order to determine the extent of the severity of an incident and to remediate the incident's effects is part of:
Correct Answer:
D
These are core functions of the incident response process.
"Incident Evaluation" is incorrect. Evaluation of the extent and cause of the incident is a component of the incident response process.
"Incident Recognition" is incorrect. Recognition that an incident has occurred is the precursor to the initiation of the incident response process.
"Incident Protection" is incorrect. This is an almost-right-sounding nonsense answer to distract the unwary.
References
CBK, pp. 698 - 703
- (Topic 4)
Which one of the following is NOT one of the outcomes of a vulnerability assessment?
Correct Answer:
C
When seeking to determine the security position of an organization, the security professional will eventually turn to a vulnerability assessment to help identify specific areas of weakness that need to be addressed. A vulnerability assessment is the use of various tools and analysis methodologies to determine where a particular system or process may be susceptible to attack or misuse. Most vulnerability assessments concentrate on technical vulnerabilities in systems or applications, but the assessment
process is equally as effective when examining physical or administrative business processes.
The vulnerability assessment is often part of a BIA. It is similar to a Risk Assessment in that there is a quantitative (financial) section and a qualitative (operational) section. It differs in that i t is smaller than a full risk assessment and is focused on providing information that is used solely for the business continuity plan or disaster recovery plan.
A function of a vulnerability assessment is to conduct a loss impact analysis. Because there will be two parts to the assessment, a financial assessment and an operational assessment, it will be necessary to define loss criteria both quantitatively and qualitatively.
Quantitative loss criteria may be defined as follows:
Incurring financial losses from loss of revenue, capital expenditure, or personal liability resolution
The additional operational expenses incurred due to the disruptive event Incurring financial loss from resolution of violation of contract agreements
Incurring financial loss from resolution of violation of regulatory or compliance requirements Qualitative loss criteria may consist of the following:
The loss of competitive advantage or market share
The loss of public confidence or credibility, or incurring public mbarrassment
During the vulnerability assessment, critical support areas must be defined in order to assess the impact of a disruptive event. A critical support area is defined as a business unit or function that must be present to sustain continuity of the business processes, maintain life safety, or avoid public relations embarrassment.
Critical support areas could include the following:
Telecommunications, data communications, or information technology areas Physical infrastructure or plant facilities, transportation services
Accounting, payroll, transaction processing, customer service, purchasing
The granular elements of these critical support areas will also need to be identified. By granular elements we mean the personnel, resources, and services the critical support areas need to maintain business continuity
Reference(s) used for this question:
Hernandez CISSP, Steven (2012-12-21). Official (ISC)2 Guide to the CISSP CBK, Third Edition ((ISC)2 Press) (Kindle Locations 4628-4632). Auerbach Publications. Kindle Edition.
KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Page 277.
- (Topic 5)
Which of the following statements pertaining to stream ciphers is correct?
Correct Answer:
B
A stream cipher is a type of symmetric encryption algorithm that operates on continuous streams of plain text and is appropriate for hardware-based encryption.
Stream ciphers can be designed to be exceptionally fast, much faster than any block cipher. A stream cipher generates what is called a keystream (a sequence of bits used as a key).
Stream ciphers can be viewed as approximating the action of a proven unbreakable cipher, the one-time pad (OTP), sometimes known as the Vernam cipher. A one-time pad uses a keystream of completely random digits. The keystream is combined with the plaintext digits one at a time to form the ciphertext. This system was proved to be secure by Claude Shannon in 1949. However, the keystream must be (at least) the same length as the plaintext, and generated completely at random. This makes the system very cumbersome to implement in practice, and as a result the one-time pad has not been widely used,
except for the most critical applications.
A stream cipher makes use of a much smaller and more convenient key — 128 bits, for example. Based on this key, it generates a pseudorandom keystream which can be combined with the plaintext digits in a similar fashion to the one-time pad. However, this comes at a cost: because the keystream is now pseudorandom, and not truly random, the proof of security associated with the one-time pad no longer holds: it is quite possible for a stream cipher to be completely insecure if it is not implemented properly as we have seen with the Wired Equivalent Privacy (WEP) protocol.
Encryption is accomplished by combining the keystream with the plaintext, usually with the bitwise XOR operation.
Source: DUPUIS, Clement, CISSP Open Study Guide on domain 5, cryptography, April 1999.
More details can be obtained on Stream Ciphers in RSA Security's FAQ on Stream Ciphers.
- (Topic 6)
Which of the following networking devices allows the connection of two or more homogeneous LANs in a simple way where they forward the traffic based on the MAC address ?
Correct Answer:
C
Bridges are simple, protocol-dependent networking devices that are used to connect two or more homogeneous LANs to form an extended LAN.
A bridge does not change the contents of the frame being transmitted but acts as a relay. A gateway is designed to reduce the problems of interfacing any combination of local
networks that employ different level protocols or local and long-haul networks.
A router connects two networks or network segments and may use IP to route messages. Firewalls are methods of protecting a network against security threats from other systems
or networks by centralizing and controlling access to the protected network segment.
Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw- Hill/Osborne, 2002, chapter 7: Telecommunications and Network Security (page 397).
