IT Certification Exam Questions & Answers

Explanation/Reference:
As it provides much of the same functionality that RSA provides: digital signatures, secure key distribution,and encryption. One differing factor is ECC’s efficiency. ECC is more efficient that RSA and any other asymmetric algorithm.
The following answers are incorrect because :
RSA is incorrect as it is less efficient than ECC to be used in handheld devices.
SHA is also incorrect as it is a hashing algorithm.
RC4 is also incorrect as it is a symmetric algorithm.
Reference : Shon Harris AIO v3 , Chapter-8 : Cryptography , Page : 631 , 638.

Section: Risk, Response and Recovery
Explanation/Reference:
Controls are implemented to mitigate risk and reduce the potential for loss. Preventive controls are put in place to inhibit harmful occurrences; detective controls are established to discover harmful occurrences; corrective controls are used to restore systems that are victims of harmful attacks.
It is not feasible and possible to eliminate all risks and the potential for loss as risk/threats are constantly changing.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 32.

Explanation/Reference:
The basic power in cryptography is randomness. This uncertainty is why encrypted data is unusable to someone without the key to decrypt.
Initialization Vectors are a used with encryption keys to add an extra layer of randomness to encrypted data. If no IV is used the attacker can possibly break the keyspace because of patterns resulting in the encryption process. Implementation such as DES in Code Book Mode (CBC) would allow frequency analysis attack to take place.
In cryptography, an initialization vector (IV) or starting variable (SV)is a fixed-size input to a cryptographic primitive that is typically required to be random or pseudorandom. Randomization is crucial for encryption schemes to achieve semantic security, a property whereby repeated usage of the scheme under the same key does not allow an attacker to infer relationships between segments of the encrypted message. For block ciphers, the use of an IV is described by so-called modes of operation. Randomization is also required for other primitives, such as universal hash functions and message authentication codes based thereon.
It is define by TechTarget as:
An initialization vector (IV) is an arbitrary number that can be used along with a secret key for data encryption. This number, also called a nonce, is employed only one time in any session.
The use of an IV prevents repetition in data encryption, making it more difficult for a hacker using a dictionary attack to find patterns and break a cipher. For example, a sequence might appear twice or more within the body of a message. If there are repeated sequences in encrypted data, an attacker could assume that the corresponding sequences in the message were also identical. The IV prevents the appearance of corresponding duplicate character sequences in the ciphertext.
The following answers are incorrect:
– Stream Cipher: This isn’t correct. A stream cipher is a symmetric key cipher where plaintext digits are combined with pseudorandom key stream to product cipher text.
– OTP – One Time Pad: This isn’t correct but OTP is made up of random values used as key material.
(Encryption key) It is considered by most to be unbreakable but must be changed with a new key after it is used which makes it impractical for common use.
– Ciphertext: Sorry, incorrect answer. Ciphertext is basically text that has been encrypted with key material (Encryption key)
The following reference(s) was used to create this question:
For more details on this TOPIC and other Qs of the Security+ CBK, subscribe to our Holistic Computer Based Tutorial (CBT) at http://www.cccure.tv
and
whatis.techtarget.com/definition/initialization-vector-IV
and
en.wikipedia.org/wiki/Initialization_vector

Attenuation is the loss of signal strength as it travels. The longer a cable, the more at tenuation occurs, which causes the signal carrying the data to deteriorate. This is why standards include suggested cable-run lengths. If a networking cable is too long, attenuation may occur. Basically, the data are in the form of electrons, and these electrons have to “swim” through a copper wire.
However, this is more like swimming upstream, because there is a lot of resistance on the electrons working in this media. After a certain distance, the electrons start to slow down and their encoding format loses form. If the form gets too degraded, the receiving system cannot interpret them any longer. If a network administrator needs to run a cable longer than its recommended segment length, she needs to insert a repeater or some type of device that will amplify the signal and ensure it gets to its destination in the right encoding format. Attenuation can also be caused by cable breaks and malfunctions. This is why cables should be tested. If a cable is suspected of attenuation problems, cable testers can inject signals into the cable and read the results at the end of the cable.
The following answers are incorrect:
Crosstalk – Crosstalk is one example of noise where unwanted electrical coupling between adjacent lines causes the signal in one wire to be picked up by the signal in an adjacent wire.
Noise – Noise is also a signal degradation but it refers to a large amount of electrical fluctuation that can interfere with the interpretation of the signal by the receiver.
Delay distortion – Delay distortion can result in a misinterpretation of a signal that results from transmitting a digital signal with varying frequency components. The various components arrive at the receiver with varying delays.

The International Standards Organization / Open Systems Interconnection
(ISO/OSI) Layers and Characteristics Standard model for network communications enables
dissimilar networks to communicate, Defines 7 protocol layers (a.k.a. protocol stack) Each
layer on one workstation communicates with its respective layer on another workstation
using protocols (i.e. agreed-upon communication formats) “Mapping” each protocol to the
model is useful for comparing protocols.
Mnemonics: Please Do Not Throw Sausage Pizza Away (bottom to top layer)
All People Seem To Need Data Processing (top to bottom layer).
Source: STEINER, Kurt, Telecommunications and Network Security, Version 1, May 2002,
CISSP Open Study Group (Domain Leader: skottikus), Page 12.

Before the advent of classless addressing, one could tell the size of a network by the first few bits of an IP address. If the first bit was set to zero (the first byte being from 0 to 127), the address was a class A network. Values from 128 to 191 were used for class B networks whereas values between 192 and 223 were used for class C networks. Class D, with values from 224 to 239 (the first three bits set to one and the fourth to zero), was reserved for IP multicast.

Explanation/Reference:
Security testing and trusted distribution are required for Life-Cycle Assurance.
The following answers are incorrect:
System Architecture and Design specification. Is incorrect because System Architecture is not requried for Life-Cycle Assurance.
Security Testing and Covert Channel Analysis. Is incorrect because Covert Channel Analysis is not requried for Life-Cycle Assurance.
Configuration Management and Trusted Facility Management. Is incorrect because Trusted Facility Management. is not requried for Life-Cycle Assurance.

Explanation/Reference:
Kerberos is a trusted, credential-based, third-party authentication protocol that uses symmetric (secret) key cryptography to provide robust authentication to clients accessing services on a network.
Because a client’s password is used in the initiation of the Kerberos request for the service protocol, password guessing can be used to impersonate a client.
Here is a nice overview of HOW Kerberos is implement as described in RFC 4556:
1. Introduction
The Kerberos V5 protocol [RFC4120] involves use of a trusted third party known as the Key Distribution Center (KDC) to negotiate shared
session keys between clients and services and provide mutual authentication between them.
The corner-stones of Kerberos V5 are the Ticket and the Authenticator. A Ticket encapsulates a symmetric key (the ticket session key) in an envelope (a public message) intended for a specific service.
The contents of the Ticket are encrypted with a symmetric key shared between the service principal and the issuing KDC. The encrypted part of the Ticket contains the client principal name, among other items.
An Authenticator is a record that can be shown to have been recently generated using the ticket session key in the associated Ticket. The ticket session key is known by the client who requested the ticket. The contents of the Authenticator are encrypted with the associated ticket session key. The encrypted part of an Authenticator contains a timestamp and the client principal name, among other items.
As shown in Figure 1, below, the Kerberos V5 protocol consists of the following message exchanges between the client and the KDC, and the
client and the application service:
The Authentication Service (AS) Exchange
The client obtains an “initial” ticket from the Kerberos authentication server (AS), typically a Ticket Granting Ticket (TGT). The AS-REQ message and the AS-REP message are the request and the reply message, respectively, between the client and the AS.
The Ticket Granting Service (TGS) Exchange
The client subsequently uses the TGT to authenticate and request a service ticket for a particular service, from the Kerberos ticket-granting server (TGS). The TGS-REQ message and the TGS-REP message are the request and the reply message respectively between the client and the TGS.
The Client/Server Authentication Protocol (AP) Exchange
The client then makes a request with an AP-REQ message, consisting of a service ticket and an authenticator that certifies the client’s possession of the ticket session key. The server may optionally reply with an AP-REP message. AP exchanges typically negotiate session-specific symmetric keys.
Usually, the AS and TGS are integrated in a single device also known as the KDC.
+————–+
+———>| KDC |
AS-REQ / +——-| |
/ / +————–+
/ / ^ |
/ |AS-REP / |
| | / TGS-REQ + TGS-REP
| | / /
| | / /
| | / +———+
| | / /
| | / /
| | / /
| v / v
++——-+——+ +—————–+
| Client +————>| Application |
| | AP-REQ | Server |
| |<————| |
+—————+ AP-REP +—————–+
Figure 1: The Message Exchanges in the Kerberos V5 Protocol
In the AS exchange, the KDC reply contains the ticket session key, among other items, that is encrypted using a key (the AS reply key)
shared between the client and the KDC. The AS reply key is typically derived from the client’s password for human users. Therefore, for
human users, the attack resistance strength of the Kerberos protocol is no stronger than the strength of their passwords.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 2: Access control systems (page 40).
And
HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 4:
Access Control (pages 147-151).
and
http://www.ietf.org/rfc/rfc4556.txt

Although TACACS+ provides better audit trails, event logging is a service that is provided with TACACS.
Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 121).

Section: Cryptography
Explanation/Reference:
In a known plaintext attack, the attacker has the plaintext and ciphertext of one or more messages. The goal is to discover the key used to encrypt the messages so that other messages can be deciphered and read.
Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 3rd Ed., chapter 8:
Cryptography (page 676). Also check out: Handbook of Applied Cryptography 4th Edition by Alfred J.
Menezes, Paul C. van Oorschot and Scott A. Vanstone.

The preventive/technical pairing uses technology to enforce access control policies.
TECHNICAL CONTROLS
Technical security involves the use of safeguards incorporated in computer hardware, operations or applications software, communications hardware and software, and related devices. Technical controls are sometimes referred to as logical controls.
Preventive Technical Controls
Preventive technical controls are used to prevent unauthorized personnel or programs from gaining remote access to computing resources. Examples of these controls include:
Access control software.
Antivirus software.
Library control systems.
Passwords.
Smart cards.
Encryption.
Dial-up access control and callback systems.
Preventive Physical Controls
Preventive physical controls are employed to prevent unauthorized personnel from entering computing facilities (i.e., locations housing computing resources, supporting utilities, computer hard copy, and input data media) and to help protect against natural disasters. Examples of these controls include:
Backup files and documentation.
Fences.
Security guards.
Badge systems.
Double door systems.
Locks and keys.
Backup power.
Biometric access controls.
Site selection.
Fire extinguishers.
Preventive Administrative Controls
Preventive administrative controls are personnel-oriented techniques for controlling people’s behavior to ensure the confidentiality, integrity, and availability of computing data and programs.
Examples of preventive administrative controls include:
Security awareness and technical training.
Separation of duties.
Procedures for recruiting and terminating employees.
Security policies and procedures.
Supervision.
Disaster recovery, contingency, and emergency plans.
User registration for computer access.

Both are the components of a sensitivity label.
The following are incorrect:
A Classification Set and a single Compartment. Is incorrect because the nomenclature “Classification Set” is incorrect, there only one classifcation and it is not a “single compartment” but a Compartment Set.
A single classification and a single compartment. Is incorrect because while there only is one classifcation, it is not a “single compartment” but a Compartment Set.
A Classification Set and user credentials. Is incorrect because the nomenclature “Classification Set” is incorrect, there only one classifcation and it is not “user credential” but a Compartment Set. The user would have their own sensitivity label.

Explanation/Reference:
Terminology can be confusing between the different souces as both CBK and AIO3 call an application layer firewall a proxy and proxy servers are generally classified as either circuit-level proxies or application level proxies.
The distinction is that a circuit level proxy creates a conduit through which a trusted host can communicate with an untrusted one and doesn’t really look at the application contents of the packet (as an application level proxy does). SOCKS is one of the better known circuit-level proxies.
Firewalls
Packet Filtering Firewall – First Generation
n Screening Router
n Operates at Network and Transport level
n Examines Source and Destination IP Address
n Can deny based on ACLs
n Can specify Port
Application Level Firewall – Second Generation
n Proxy Server
n Copies each packet from one network to the other
n Masks the origin of the data
n Operates at layer 7 (Application Layer)
n Reduces Network performance since it has do analyze each packet and decide what to do with it.
n Also Called Application Layer Gateway
Stateful Inspection Firewalls – Third Generation
n Packets Analyzed at all OSI layers
n Queued at the network level
n Faster than Application level Gateway
Dynamic Packet Filtering Firewalls – Fourth Generation
n Allows modification of security rules
n Mostly used for UDP
n Remembers all of the UDP packets that have crossed the network’s perimeter, and it decides whether to enable packets to pass through the firewall.
Kernel Proxy – Fifth Generation
n Runs in NT Kernel
n Uses dynamic and custom TCP/IP-based stacks to inspect the network packets and to enforce security policies.
“Current level firewall” is incorrect. This is an amost-right-sounding distractor to confuse the unwary.
“Cache level firewall” is incorrect. This too is a distractor.
“Session level firewall” is incorrect. This too is a distractor.
References
CBK, p. 466 – 467
AIO3, pp. 486 – 490
CISSP Study Notes from Exam Prep Guide

Section: Risk, Response and Recovery
Explanation/Reference:
Risk is the likelihood of a threat agent taking advantage of a vulnerability and the corresponding business impact. If a firewall has several ports open , there is a higher likelihood that an intruder will use one to access the network in an unauthorized method.
The following answers are incorrect :
Residual Risk is very different from the notion of total risk. Residual Risk would be the risks that still exists after countermeasures have been implemented. Total risk is the amount of risk a company faces if it chooses not to implement any type of safeguard.
Exposure: An exposure is an instance of being exposed to losses from a threat agent.
Countermeasure: A countermeasure or a safeguard is put in place to mitigate the potential risk. Examples of countermeasures include strong password management , a security guard.
REFERENCES : SHON HARRIS ALL IN ONE 3rd EDITION
Chapter – 3: Security Management Practices , Pages : 57-59

Explanation/Reference:
The main difference between memory cards and smart cards is their capacity to process information. A memory card holds information but cannot process information. A smart card holds information and has the necessary hardware and software to actually process that information.
A memory card holds a user’s authentication information, so that this user needs only type in a user ID or PIN and presents the memory card to the system. If the entered information and the stored information match and are approved by an authentication service, the user is successfully authenticated.
A common example of a memory card is a swipe card used to provide entry to a building. The user enters a PIN and swipes the memory card through a card reader. If this is the correct combination, the reader flashes green and the individual can open the door and enter the building.
Memory cards can also be used with computers, but they require a reader to process the information. The reader adds cost to the process, especially when one is needed for every computer. Additionally, the overhead of PIN and card generation adds additional overhead and complexity to the whole authentication process. However, a memory card provides a more secure authentication method than using only a password because the attacker would need to obtain the card and know the correct PIN.
Administrators and management need to weigh the costs and benefits of a memory card implementation as well as the security needs of the organization to determine if it is the right authentication mechanism for their environment.
One of the most prevalent weaknesses of memory cards is that data stored on the card are not protected.
Unencrypted data on the card (or stored on the magnetic strip) can be extracted or copied. Unlike a smart card, where security controls and logic are embedded in the integrated circuit, memory cards do not employ an inherent mechanism to protect the data from exposure.
Very little trust can be associated with confidentiality and integrity of information on the memory cards.
The following answers are incorrect:
“Smart cards provide two-factor authentication whereas memory cards don’t” is incorrect. This is not necessarily true. A memory card can be combined with a pin or password to offer two factors authentication where something you have and something you know are used for factors.
“Memory cards normally hold more memory than smart cards” is incorrect. While a memory card may or may not have more memory than a smart card, this is certainly not the best answer to the question.
“Only smart cards can be used for ATM cards” is incorrect. This depends on the decisions made by the particular institution and is not the best answer to the question.
Reference(s) used for this question:
Shon Harris, CISSP All In One, 6th edition , Access Control, Page 199 and also for people using the Kindle edition of the book you can look at Locations 4647-4650.
Schneiter, Andrew (2013-04-15). Official (ISC)2 Guide to the CISSP CBK, Third Edition : Access Control ((ISC)2 Press) (Kindle Locations 2124-2139). Auerbach Publications. Kindle Edition.

Section: Access Control
Explanation/Reference:
Single Sign-On is a distrubuted Access Control methodology where an individual only has to authenticate once and would have access to all primary and secondary network domains. The individual would not be required to re-authenticate when they needed additional resources. The security issue that this creates is if a fraudster is able to compromise those credential they too would have access to all the resources that account has access to.
All the other answers are incorrect as they are distractors.

The application firewall (proxy) relays the traffic from a trusted host running a specific application to an untrusted server. It will appear to the untrusted server as if the request originated from the proxy server.
“Data’s payload” is incorrect. Only the origin is changed. “Data’s details” is incorrect. Only the origin is changed. “Data’s owner” is incorrect. Only the origin is changed.
References:
CBK, p. 467 AIO3, pp. 486 – 490

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.

Explanation/Reference:
The MOST common threat that impacts a business’s ability to function normally is power. Power interruption cause more business interruption than any other type of event.
The second most common threat is Water such as flood, water damage from broken pipe, leaky roof, etc…
Threats will be discovered while doing your Threats and Risk Assessments (TRA).
There are three elements of risks: threats, assets, and mitigating factors (countermeasures, safeguards, controls).
A threat is an event or situation that if it occured would affect your business and may even prevent it from functioning normally or in some case functioning at all. Evaluation of threats is done by looking at Likelihood and Impact of possible threat. Safeguards, countermeasures, and controls would be used to bring the threat level down to an acceptable level.
Other common events that can impact a company are:
Weather, cable cuts, fires, labor disputes, transportation mishaps, hardware failure, chemical spills, sabotage.
References:
The Official ISC2 Guide to the CISSP CBK, Second Edition, Page 275-276

Section: Network and Telecommunications
Explanation
Explanation/Reference: RFC 2409: The Internet Key Exchange (IKE); DORASWAMY, Naganand & HARKINS, Dan, Ipsec:
The New Security Standard for the Internet, Intranets, and Virtual Private Networks, 1999, Prentice Hall PTR; SMITH, Richard E., Internet Cryptography, 1997, Addison-Wesley Pub Co.

You data center should be located in the middle of the facility or the core of a building to provide protection from natural disasters or bombs and provide easier access to emergency crewmembers if necessary. By being at the core of the facility the external wall would act as a secondary layer of protection as well.
Information processing facilities should not be located on the top floors of buildings in case of a fire or flooding coming from the roof. Many crimes and theft have also been conducted by simply cutting a large hole on the roof.
They should not be in the basement because of flooding where water has a natural tendancy to flow down 🙂 Even a little amount of water would affect your operation considering the quantity of electrical cabling sitting directly on the cement floor under under your raise floor.
The data center should not be located on the first floor due to the presence of the main entrance where people are coming in and out. You have a lot of high traffic areas such as the elevators, the loading docks, cafeteria, coffee shopt, etc.. Really a bad location for a data center.
So it was easy to come up with the answer by using the process of elimination where the top, the bottom, and the basement are all bad choices. That left you with only one possible answer which is the third floor. Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, 5th Edition, Page
425.

With mirroring, the system writes the data simultaneously to separate drives or arrays.
The advantage of mirroring are minimal downtime, simple data recovery, and increased performance in reading from the disk.
The disadvantage of mirroring is that both drives or disk arrays are processing in the writing to disks function, which can hinder system performance.
Mirroring has a high fault tolerance and can be implemented either through a hardware RAID controller or through the operating system. Since it requires twice the disk space than actual data, mirroring is the less cost-efficient data redundancy strategy.

Confidentiality is defined as the property that ensures that only the intended recipient can access the data and nobody else. It is usually achieve using cryptogrphic methods, tools, and protocols.
Confidentiality supports the principle of “least privilege” by providing that only authorized individuals, processes, or systems should have access to information on a need-to-know basis. The level of access that an authorized individual should have is at the level necessary for them to do their job. In recent years, much press has been dedicated to the privacy of information and the need to protect it from individuals, who may be able to commit crimes by viewing the information. Identity theft is the act of assuming one’s identity through knowledge of confidential information obtained from various sources.
The following are incorrect answers: Capability is incorrect. Capability is relevant to access control. Capability-based security is a concept in the design of secure computing systems, one of the existing security models. A capability (known in some systems as a key) is a communicable, unforgeable token of authority. It refers to a value that references an object along with an associated set of access rights. A user program on a capability-based operating system must use a capability to access an object. Capability-based security refers to the principle of designing user programs such that they directly share capabilities with each other according to the principle of least privilege, and to the operating system infrastructure necessary to make such transactions efficient and secure.
Integrity is incorrect. Integrity protects information from unauthorized modification or loss. Availability is incorrect. Availability assures that information and services are available for use by authorized entities according to the service level objective.
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 9345-9349). Auerbach Publications. Kindle Edition. http://en.wikipedia.org/wiki/Capability-based_security