Free ISC2 Systems Security Certified Practitioner SSCP Exam Questions

The software plans and requirements phase addresses threats, vulnerabilities, security requirements, reasonable care, due diligence, legal liabilities, cost/benefit analysis, level of protection desired, test plans.

Implementation is incorrect because it deals with Installing security software, running the system, acceptance testing, security software testing, and complete documentation certification and accreditation (where necessary).

System Feasibility is incorrect because it deals with information security policy, standards, legal issues, and the early validation of concepts.

Product design is incorrect because it deals with incorporating security specifications, adjusting test plans and data,

determining access controls, design documentation, evaluating encryption options, and verification.

Sources:

KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 7: Applications and Systems Development (page 252).

KRUTZ, Ronald & VINES, Russel, The CISSP Prep Guide: Gold Edition, Wiley Publishing Inc., 2003, Chapter 7: Security Life Cycle Components, Figure 7.5 (page 346).

Because a network-based IDS reviews packets and headers, denial of service attacks can also be detected.

This question is an easy question if you go through the process of elimination. When you see an answer containing the keyword: ALL It is something a give away that it is not the proper answer. On the real exam you may encounter a few question where the use of the work ALL renders the choice invalid. Pay close attention to such keyword.

The following are incorrect answers:

Even though most IDSs can detect some viruses and some password guessing attacks, they cannot detect ALL viruses or ALL password guessing attacks. Therefore these two answers are only detractors.

Unless the IDS knows the valid values for a certain dataset, it can NOT detect data corruption.

Reference used for this question:

KRUTZ,

Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 48.

If we assume a crytpo-system with a large key (and therefore a large key space) a brute force attack will likely take a good deal of time - anywhere from several hours to several years depending on a number of variables. If you use a session key for each message you encrypt, then the brute force attack provides the attacker with only the key for that one message. So, if you are encrypting 10 messages a day, each with a different session key, but it takes me a month to break each session key then I am fighting a loosing battle.

The other answers are not correct because:

'The use of good key generators' is not correct because a brute force key attack will eventually run through all possible combinations of key. Therefore, any key will eventually be broken in this manner given enough time.

'Nothing can defend you against a brute force crypto key attack' is incorrect, and not the best answer listed. While it is technically true that any key will eventually be broken by a brute force attack, the question remains 'how long will it take?'. In other words, if you encrypt something today but I can't read it for 10,000 years, will you still care? If the key is changed every session does it matter if it can be broken after the session has ended? Of the answers listed here, session keys are 'often considered a good protection against the brute force cryptography attack' as the question asks.

'Algorithms that are immune to brute force key attacks' is incorrect because there currently are no such algorithms.

References:

Official ISC2 Guide page: 259

All in One Third Edition page: 623

Because the contingency plan contains potentially sensitive operational and personnel information, its distribution should be marked accordingly and controlled. Not all employees would obtain a copy, but only those involved in the execution of the plan.

All other statements are correct.

NOTE FROM CLEMENT:

I have received multiple emails stating the explanations contradict the correct answer. It seems many people have a hard time with negative question. In this case the Incorrect choice (the one that is not true) is the correct choice. Be very carefull of such questions, you will get some on the real exam as well.

Reference(s) used for this question:

SWANSON,

Marianne, & al., National Institute of Standards and Technology (NIST), NIST Special Publication 800-34, Contingency Planning Guide for Information Technology Systems

A host-based IDS can review the system and event logs in order to detect an attack on the host and to determine if the attack was successful.

Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 48.

Test equipment must be secured. There are equipment and other tools that if in the wrong hands could be used to 'sniff' network traffic and also be used to commit fraud. The storage and use of this equipment should be detailed in the security policy for this reason.

The following answers are incorrect:

Test equipment is easily damaged. Is incorrect because it is not the best answer, and from a security point of view not relevent.

Test equipment is difficult to replace if lost or stolen. Is incorrect because it is not the best answer, and from a security point of view not relevent.

Test equipment must always be available for the maintenance personnel. Is incorrect because it is not the best answer, and from a security point of view not relevent.

References:

OIG CBK Operations Security (pages 642 - 643)

Knowlege of modem numbers is a poor access control method as an attacker can discover modem numbers by dialing all numbers in a range. Requiring user authentication before remote access is granted will help in avoiding unauthorized access over a modem line.

'Monitoring and auditing for such activity' is incorrect. While monitoring and auditing can assist in detecting a wardialing attack, they do not defend against a successful wardialing attack.

'Making sure that only necessary phone numbers are made public' is incorrect. Since a wardialing attack blindly calls all numbers in a range, whether certain numbers in the range are public or not is irrelevant.

'Using completely different numbers for voice and data accesses' is incorrect. Using different number ranges for voice and data access might help prevent an attacker from stumbling across the data lines while wardialing the public voice number range but this is not an adequate countermeaure.

References:

CBK, p. 214

AIO3, p. 534-535

The other answers are not correct because:

You are always looking for the 'best' answer. While each of the answers listed here could be considered correct in that each of them require input from the security staff, the best answer is for that input to happen at all phases of the project.

Official ISC2 Guide page: 556

All in One Third Edition page: 832 - 833

When a biometric system is used for access control, the most important error is the false accept or false acceptance rate, or Type II error, where the system would accept an impostor.

A Type I error is known as the false reject or false rejection rate and is not as important in the security context as a type II error rate. A type one is when a valid company employee is rejected by the system and he cannot get access even thou it is a valid user.

The Crossover Error Rate (CER) is the point at which the false rejection rate equals the false acceptance rate if your would create a graph of Type I and Type II errors. The lower the CER the better the device would be.

The Combined Error Rate is a distracter and does not exist.

Source: TIPTON, Harold F. & KRAUSE, Micki, Information Security Management Handbook, 4th edition (volume 1), 2000, CRC Press, Chapter 1, Biometric Identification (page 10).

Once an intrusion into your organization's information system has been detected, the first action that needs to be performed is determining to what extent systems and data are compromised (if they really are), and then take action.

This is the good old saying: 'Do not cry wolf until you know there is a wolf for sure' Sometimes it smells like a wolf, it looks like a wolf, but it may not be a wolf. Technical problems or bad hardware might cause problems that looks like an intrusion even thou it might not be. You must make sure that a crime has in fact been committed before implementing your reaction plan.

Information, as collected and interpreted through analysis, is key to your decisions and actions while executing response procedures. This first analysis will provide information such as what attacks were used, what systems and data were accessed by the intruder, what the intruder did after obtaining access and what the intruder is currently doing (if the intrusion has not been contained).

The next step is to communicate with relevant parties who need to be made aware of the intrusion in a timely manner so they can fulfil their responsibilities.

Step three is concerned with collecting and protecting all information about the compromised systems and causes of the intrusion. It must be carefully collected, labelled, catalogued, and securely stored.

Containing the intrusion, where tactical actions are performed to stop the intruder's access, limit the extent of the intrusion, and prevent the intruder from causing further damage, comes next.

Since it is more a long-term goal, eliminating all means of intruder access can only be achieved last, by implementing an ongoing security improvement process.

Reference used for this question:

ALLEN,

Julia H., The CERT Guide to System and Network Security Practices, Addison-Wesley, 2001, Chapter 7: Responding to Intrusions (pages 271-289).

A stream cipher treats the message as a stream of bits or bytes and performs mathematical functions on them individually. The key is a random value input into the stream cipher, which it uses to ensure the randomness of the keystream data. They are more suitable for hardware implementations, because they encrypt and decrypt one bit at a time. They are intensive because each bit must be manipulated, which works better at the silicon level. Block ciphers operate a the block level, dividing the message into blocks of bits. Cipher Block chaining (CBC) and Electronic Code Book (ECB) are operation modes of DES, a block encryption algorithm.

Source: WALLHOFF, John, CBK#5 Cryptography (CISSP Study Guide), April 2002 (page 2).

RC4 was designed by Ron Rivest of RSA Security in 1987. While it is officially termed 'Rivest Cipher 4', the RC acronym is alternatively understood to stand for 'Ron's Code' (see also RC2, RC5 and RC6).

RC4 was initially a trade secret, but in September 1994 a description of it was anonymously posted to the Cypherpunks mailing list. It was soon posted on the sci.crypt newsgroup, and from there to many sites on the Internet. The leaked code was confirmed to be genuine as its output was found to match that of proprietary software using licensed RC4. Because the algorithm is known, it is no longer a trade secret. The name RC4 is trademarked, so RC4 is often referred to as ARCFOUR or ARC4 (meaning alleged RC4) to avoid trademark problems. RSA Security has never officially released the algorithm; Rivest has, however, linked to the English Wikipedia article on RC4 in his own course notes. RC4 has become part of some commonly used encryption protocols and standards, including WEP and WPA for wireless cards and TLS.

The main factors in RC4's success over such a wide range of applications are its speed and simplicity: efficient implementations in both software and hardware are very easy to develop.

The following answer were not correct choices:

SHA-1 is a one-way hashing algorithms. SHA-1 is a cryptographic hash function designed by the United States National Security Agency and published by the United States NIST as a U.S. Federal Information Processing Standard. SHA stands for 'secure hash algorithm'.

The three SHA algorithms are structured differently and are distinguished as SHA-0, SHA-1, and SHA-2. SHA-1 is very similar to SHA-0, but corrects an error in the original SHA hash specification that led to significant weaknesses. The SHA-0 algorithm was not adopted by many applications. SHA-2 on the other hand significantly differs from the SHA-1 hash function.

SHA-1 is the most widely used of the existing SHA hash functions, and is employed in several widely used security applications and protocols. In 2005, security flaws were identified in SHA-1, namely that a mathematical weakness might exist, indicating that a stronger hash function would be desirable. Although no successful attacks have yet been reported on the SHA-2 variants, they are algorithmically similar to SHA-1 and so efforts are underway to develop improved alternatives. A new hash standard, SHA-3, is currently under development --- an ongoing NIST hash function competition is scheduled to end with the selection of a winning function in 2012.

SHA-1 produces a 160-bit message digest based on principles similar to those used by Ronald L. Rivest of MIT in the design of the MD4 and MD5 message digest algorithms, but has a more conservative design.

MD2 is a one-way hashing algorithms. The MD2 Message-Digest Algorithm is a cryptographic hash function developed by Ronald Rivest in 1989. The algorithm is optimized for 8-bit computers. MD2 is specified in RFC 1319. Although MD2 is no longer considered secure, even as of 2010 it remains in use in public key infrastructures as part of certificates generated with MD2 and RSA.

Haval is a one-way hashing algorithms. HAVAL is a cryptographic hash function. Unlike MD5, but like most modern cryptographic hash functions, HAVAL can produce hashes of different lengths. HAVAL can produce hashes in lengths of 128 bits, 160 bits, 192 bits, 224 bits, and 256 bits. HAVAL also allows users to specify the number of rounds (3, 4, or 5) to be used to generate the hash.

The following reference(s) were used for this question:

SHIREY,

Robert W., RFC2828: Internet Security Glossary, may 2000.

and

https://en.wikipedia.org/wiki/HAVAL

and

https://en.wikipedia.org/wiki/MD2_%28cryptography%29

and

https://en.wikipedia.org/wiki/SHA-1

The cost of a countermeasure should not be greater in cost than the risk it mitigates (ALE). For a quantitative risk assessment, the equation is ALE = ARO x SLE where the SLE is calculated as the product of asset value x exposure factor. An event that happen once every five years would have an ARO of .2 (1 divided by 5).

SLE = Asset Value (AV) x Exposure Fact (EF)

SLE = 1,000,000 x .30 = 300,000

ALE = SLE x Annualized Rate of Occurance (ARO)

ALE = 300,000 x .2 = 60,000

Know your acronyms:

ALE -- Annual loss expectancy

ARO -- Annual rate of occurrence

SLE -- Single loss expectancy

The following are incorrect answers:

$300,000 is incorrect. See the explanation of the correct answer for the correct calculation.

$150,000 is incorrect. See the explanation of the correct answer for the correct calculation.

$1,500 is incorrect. See the explanation of the correct answer for the correct calculation.

Reference(s) used for this question:

Mc Graw

Hill, Shon Harris, CISSP All In One (AIO) book, Sixth Edition , Pages 87-88

and

Official ISC2 Guide to the CISSP Exam, (OIG), Pages 60-61

In cryptography, the one-time pad (OTP) is a type of encryption that is impossible to crack if used correctly. Each bit or character from the plaintext is encrypted by a modular addition with a bit or character from a secret random key (or pad) of the same length as the plaintext, resulting in a ciphertext. If the key is truly random, at least as long as the plaintext, never reused in whole or part, and kept secret, the ciphertext will be impossible to decrypt or break without knowing the key. It has also been proven that any cipher with the perfect secrecy property must use keys with effectively the same requirements as OTP keys. However, practical problems have prevented one-time pads from being widely used.

First described by Frank Miller in 1882, the one-time pad was re-invented in 1917 and patented a couple of years later. It is derived from the Vernam cipher, named after Gilbert Vernam, one of its inventors. Vernam's system was a cipher that combined a message with a key read from a punched tape. In its original form, Vernam's system was vulnerable because the key tape was a loop, which was reused whenever the loop made a full cycle. One-time use came a little later when Joseph Mauborgne recognized that if the key tape were totally random, cryptanalysis would be impossible.

The 'pad' part of the name comes from early implementations where the key material was distributed as a pad of paper, so the top sheet could be easily torn off and destroyed after use. For easy concealment, the pad was sometimes reduced to such a small size that a powerful magnifying glass was required to use it. Photos show captured KGB pads that fit in the palm of one's hand, or in a walnut shell. To increase security, one-time pads were sometimes printed onto sheets of highly flammable nitrocellulose so they could be quickly burned.

The following are incorrect answers:

A running key cipher uses articles in the physical world rather than an electronic algorithm. In classical cryptography, the running key cipher is a type of polyalphabetic substitution cipher in which a text, typically from a book, is used to provide a very long keystream. Usually, the book to be used would be agreed ahead of time, while the passage to use would be chosen randomly for each message and secretly indicated somewhere in the message.

The Running Key cipher has the same internal workings as the Vigenere cipher. The difference lies in how the key is chosen; the Vigenere cipher uses a short key that repeats, whereas the running key cipher uses a long key such as an excerpt from a book. This means the key does not repeat, making cryptanalysis more difficult. The cipher can still be broken though, as there are statistical patterns in both the key and the plaintext which can be exploited.

Steganography is a method where the very existence of the message is concealed. It is the art and science of encoding hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message. it is sometimes referred to as Hiding in Plain Sight.

Cipher block chaining is a DES operating mode. IBM invented the cipher-block chaining (CBC) mode of operation in 1976. In CBC mode, each block of plaintext is XORed with the previous ciphertext block before being encrypted. This way, each ciphertext block depends on all plaintext blocks processed up to that point. To make each message unique, an initialization vector must be used in the first block.

Reference(s) used for this question:

HARRIS,

Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 8: Cryptography (page 555).

and

http://en.wikipedia.org/wiki/One-time_pad

http://en.wikipedia.org/wiki/Running_key_cipher

http://en.wikipedia.org/wiki/Cipher_block_chaining#Cipher-block_chaining_.28CBC.29

Symmetric-key algorithms are a class of algorithms for cryptography that use the same cryptographic keys for both encryption of plaintext (sender) and decryption of ciphertext (receiver). The keys may be identical, in practice, they represent a shared secret between two or more parties that can be used to maintain a private information link.

This requirement that both parties have access to the secret key is one of the main drawbacks of symmetric key encryption, in comparison to public-key encryption. This is also known as secret key encryption. In symmetric key cryptography, each end of the conversation must have the same key or they cannot decrypt the message sent to them by the other party.

Symmetric key crypto is very fast but more difficult to manage due to the need to distribute the key in a secure means to all parts needing to decrypt the data. There is no key management built within Symmetric crypto.

PKI provides CIA - Confidentiality (Through encryption) Integrity (By guaranteeing that the message hasn't change in transit) and Authentication (Non-repudiation). Symmetric key crypto provides mostly Confidentiality.

The following answers are incorrect:

- PKI - Public Key Infrastructure: This is the opposite of symmetric key crypto. Each side in PKI has their own private key and public key. What one key encrypt the other one can decrypt. You make use of the receiver public key to communicate securely with a remote user. The receiver will use their matching private key to decrypt the data.

- Diffie-Hellman: Sorry, this is an asymmetric key technique. It is used for key agreement over an insecure network such as the Internet. It allows two parties who has never met to negotiate a secret key over an insecure network while preventing Man-In-The-Middle (MITM) attacks.

- DSS - Digital Signature Standard: Sorry, this is an asymmetric key technique.

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

To learn

more about this

Questions; and 100% of the Security+ CBK, subscribe to our Holistic Computer Based Tutorial (CBT) on our Learning Management System at: http://www.cccure.tv

and

http://en.wikipedia.org/wiki/Symmetric-key_algorithm