Which of the following is not a disadvantage of symmetric cryptography when compared with Asymmetric Ciphers?
正解: C
Section: Cryptography Explanation/Reference: Symmetric cryptography ciphers are generally fast and hard to break. So speed is one of the key advantage of Symmetric ciphers and NOT a disadvantage. Symmetric Ciphers uses simple encryption steps such as XOR, substitution, permutation, shifting columns, shifting rows, etc... Such steps does not required a large amount of processing power compare to the complex mathematical problem used within Asymmetric Ciphers. Some of the weaknesses of Symmetric Ciphers are: The lack of automated key distribution. Usually an Asymmetric cipher would be use to protect the symmetric key if it needs to be communicated to another entity securely over a public network. In the good old day this was done manually where it was distributed using the Floppy Net sometimes called the Sneaker Net (you run to someone's office to give them the key). As far as the total number of keys are required to communicate securely between a large group of users, it does not scale very well. 10 users would require 45 keys for them to communicate securely with each other. If you have 1000 users then you would need almost half a million key to communicate secure. On Asymmetric ciphers there is only 2000 keys required for 1000 users. The formula to calculate the total number of keys required for a group of users who wishes to communicate securely with each others using Symmetric encryption is Total Number of Users (N) * Total Number of users minus one Divided by 2 or N (N- 1)/2 Symmetric Ciphers are limited when it comes to security services, they cannot provide all of the security services provided by Asymmetric ciphers. Symmetric ciphers provides mostly confidentiality but can also provide integrity and authentication if a Message Authentication Code (MAC) is used and could also provide user authentication if Kerberos is used for example. Symmetric Ciphers cannot provide Digital Signature and Non-Repudiation. Reference used for theis question: WALLHOFF, John, CBK#5 Cryptography (CISSP Study Guide), April 2002 (page 2).
SSCP 試験問題 202
Which of the following is NOT a characteristic of a host-based intrusion detection system?
正解: A
Explanation/Reference: A HIDS does not consume large amounts of system resources is the correct choice. HIDS can consume inordinate amounts of CPU and system resources in order to function effectively, especially during an event. All the other answers are characteristics of HIDSes A HIDS can: scrutinize event logs, critical system files, and other auditable system resources; look for unauthorized change or suspicious patterns of behavior or activity can send alerts when unusual events are discovered Reference: Official guide to the CISSP CBK. Pages 197 to 198.
SSCP 試験問題 203
Examples of types of physical access controls include all EXCEPT which of the following?
正解: D
Section: Access Control Explanation/Reference: Passwords are considered a Preventive/Technical (logical) control. The following answers are incorrect: badges Badges are a physical control used to identify an individual. A badge can include a smart device which can be used for authentication and thus a Technical control, but the actual badge itself is primarily a physical control. locks Locks are a Preventative Physical control and has no Technical association. guards Guards are a Preventative Physical control and has no Technical association. The following reference(s) were/was used to create this question: 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 35).
SSCP 試験問題 204
Which of the following statements pertaining to disk mirroring is incorrect?
正解: B
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. Source: SWANSON, Marianne, & al., National Institute of Standards and Technology (NIST), NIST Special Publication 800-34, Contingency Planning Guide for Information Technology Systems, December 2001 (page 45).
SSCP 試験問題 205
What is electronic vaulting?
正解: D
Electronic vaulting is defined as "a method of transferring bulk information to off-site facilities for backup purposes". Remote Journaling is the same concept as electronic vaulting, but has to do with journals and transaction logs, not the actual files. Source: HARRIS, Shon, All-In-One CISSP Certification Exam Guide, McGraw-Hill/Osborne, 2002, chapter 9: Disaster Recovery and Business continuity (page 619).