Section: Cryptography
Explanation/Reference:
When a concealment cipher is used, every X number of words within a text, is a part of the real message. The message is within another message.
A concealment cipher is a message within a message. If my other super-secret spy buddy and I decide our key value is every third word, then when I get a message from him, I will pick out every third word and write it down.
Suppose he sends me a message that reads, "The saying, 'The time is right' is not cow language, so is now a dead subject." Because my key is every third word, I come up with "The right cow is dead." This again means nothing to me, and I am now turning in my decoder ring.
Concealment ciphers include the plaintext within the ciphertext. It is up to the recipient to know which letters or symbols to exclude from the ciphertext in order to yield the plaintext. Here is an example of a concealment cipher:
i2l32i5321k34e1245ch456oc12ol234at567e
Remove all the numbers, and you'll have i like chocolate. How about this one?
Larry even appears very excited. No one worries.
The first letter from each word reveals the message leave now. Both are easy, indeed, but many people have crafted more ingenious ways of concealing the messages. By the way, this type of cipher doesn't even need ciphertext, such as that in the above examples.
Consider the invisible drying ink that kids use to send secret messages. In a more extreme example, a man named Histiaeus, during 5th century B.C., shaved the head of a trusted slave, then tattooed the message onto his bald head. When the slave's hair grew back, Histiaeus sent the slave to the message's intended recipient, Aristagoros, who shaved the slave's head and read the message instructing him to revolt.
The following answers are incorrect:
A transposition cipher uses permutations.
A substitution cipher replaces bits, characters, or blocks of characters with different bits, characters or blocks.
Steganography refers to hiding the very existence of the message.
Source: WALLHOFF, John, CBK#5 Cryptography (CISSP Study Guide), April 2002 (page 1).
and also see:
http://www.go4expert.com/forums/showthread.php?t=415

Repeaters offer the simplest form of connectivity. They regenerate received electrical signals at their original strength between cable segments. Bridges are devices used to connect similar or dissimilar LANs together to form an extended LAN. Routers provide packet routing between network segments. Brouter are devices that combine router and bridge functionality. Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 7: Telecommunications and Network Security (page 397).

Explanation/Reference:
Accreditation is the authorization by management to implement software or systems in a production environment. This authorization may be either provisional or full.
The following are incorrect answers:
Certification is incorrect. Certification is the process of evaluating the security stance of the software or system against a selected set of standards or policies. Certification is the technical evaluation of a product. This may precede accreditation but is not a required precursor.
Acceptance is incorrect. This term is sometimes used as the recognition that a piece of software or system has met a set of functional or service level criteria (the new payroll system has passed its acceptance test).
Certification is the better tem in this context.
Evaluation is incorrect. Evaluation is certainly a part of the certification process but it is not the best answer to the question.
Reference(s) used for this question:
The Official Study Guide to the CBK from ISC2, pages 559-560
AIO3, pp. 314 - 317
AIOv4 Security Architecture and Design (pages 369 - 372)
AIOv5 Security Architecture and Design (pages 370 - 372)

Section: Cryptography
Explanation/Reference:
The other answers are not correct because:
"Rivest, Shamir, Adleman (RSA)" is incorrect because RSA is a "traditional" asymmetric algorithm. While it is reasonably strong, it is not considered to be as strong as ECC based systems.
"El Gamal" is incorrect because it is also a "traditional" asymmetric algorithm and not considered as strong as ECC based systems.
"Advanced Encryption Standard (AES)" is incorrect because the question asks specifically about asymmetric algorithms and AES is a symmetric algorithm.
References:
Official ISC2 Guide page: 258
All in One Third Edition page: 638
The RSA Crypto FAQ: http://www.rsa.com/rsalabs/node.asp?id=2241

Explanation/Reference:
The network layer contains the Internet Protocol (IP), the Internet Control Message Protocol (ICMP), and the Internet Group Management Protocol (IGMP)
The following answers are incorrect:
Datagram Layer. Is incorrect as a distractor as there is no Datagram Layer.
Transport Layer. Is incorrect because it is used to data between applications and uses the TCP and UDP protocols.
Data Link Layer. Is incorrect because this layer deals with addressing hardware.