Which of the following algorithms does NOT provide hashing?
Correct Answer: C
As it is an algorithm used for encryption and does not provide hashing functions , it is also commonly implemented ' Stream Ciphers '. The other answers are incorrect because : SHA-1 was designed by NIST and NSA to be used with the Digital Signature Standard (DSS). SHA was designed to be used in digital signatures and was developed when a more secure hashing algorithm was required for U.S. government applications. MD2 is a one-way hash function designed by Ron Rivest that creates a 128-bit message digest value. It is not necessarily any weaker than the other algorithms in the "MD" family, but it is much slower. MD5 was also created by Ron Rivest and is the newer version of MD4. It still produces a 128-bit hash, but the algorithm is more complex, which makes it harder to break. Reference : Shon Harris , AIO v3 , Chapter - 8 : Cryptography , Page : 644 - 645
Question 212
When developing solutions for mobile devices, in which phase of the Software Development Life Cycle (SDLC) should technical limitations related to devices be specified?
Correct Answer: A
Section: Software Development Security
Question 213
The IS security analyst's participation in which of the following system development life cycle phases provides maximum benefit to the organization?
Correct Answer: D
Question 214
Which ISO/OSI layer establishes the communications link between individual devices over a physical link or channel?
Correct Answer: C
Explanation/Reference: Explanation: The data link layer is responsible for proper communication within the network devices and for changing the data into the necessary format (electrical voltage) for the physical link or channel. Incorrect Answers: A: The protocols at the transport layer handle end-to-end transmission and segmentation of a data stream. B: The responsibilities of the network layer protocols include internetworking service, addressing, and routing. D: The physical layer include network interface cards and drivers that convert bits into electrical signals and control the physical aspects of data transmission References: Harris, Shon, All In One CISSP Exam Guide, 6th Edition, McGraw-Hill, New York, 2013, p. 531
Question 215
Which of the following is an extension to Network Address Translation that permits multiple devices providing services on a local area network (LAN) to be mapped to a single public IP address?
Correct Answer: C
Port Address Translation (PAT), is an extension to network address translation (NAT) that permits multiple devices on a local area network (LAN) to be mapped to a single public IP address. The goal of PAT is to conserve IP addresses or to publish multiple hosts with service to the internet while having only one single IP assigned on the external side of your gateway. Most home networks use PAT. In such a scenario, the Internet Service Provider (ISP) assigns a single IP address to the home network's router. When Computer X logs on the Internet, the router assigns the client a port number, which is appended to the internal IP address. This, in effect, gives Computer X a unique address. If Computer Z logs on the Internet at the same time, the router assigns it the same local IP address with a different port number. Although both computers are sharing the same public IP address and accessing the Internet at the same time, the router knows exactly which computer to send specific packets to because each computer has a unique internal address. Port Address Translation is also called porting, port overloading, port-level multiplexed NAT and single address NAT. Shon Harris has the following example in her book: The company owns and uses only one public IP address for all systems that need to communicate outside the internal network. How in the world could all computers use the exact same IP address? Good question. Here's an example: The NAT device has an IP address of 127.50.41.3. When computer A needs to communicate with a system on the Internet, the NAT device documents this computer's private address and source port number (10.10.44.3; port 43,887). The NAT device changes the IP address in the computer's packet header to 127.50.41.3, with the source port 40,000. When computer B also needs to communicate with a system on the Internet, the NAT device documents the private address and source port number (10.10.44.15; port 23,398) and changes the header information to 127.50.41.3 with source port 40,001. So when a system responds to computer A, the packet first goes to the NAT device, which looks up the port number 40,000 and sees that it maps to computer A's real information. So the NAT device changes the header information to address 10.10.44.3 and port 43,887 and sends it to computer A for processing. A company can save a lot more money by using PAT, because the company needs to buy only a few public IP addresses, which are used by all systems in the network. As mentioned on Wikipedia: NAT is also known as Port Address Translation: is a feature of a network device that translate TCP or UDP communications made between host on a private network and host on a public network. I allows a single public IP address to be used by many host on private network which is usually a local area network LAN NAT effectively hides all TCP/IP-level information about internal hosts from the Internet. The following were all incorrect answer: IP Spoofing - In computer networking, the term IP address spoofing or IP spoofing refers to the creation of Internet Protocol (IP) packets with a forged source IP address, called spoofing, with the purpose of concealing the identity of the sender or impersonating another computing system. Subnetting - Subnetting is a network design strategy that segregates a larger network into smaller components. While connected through the larger network, each subnetwork or subnet functions with a unique IP address. All systems that are assigned to a particular subnet will share values that are common for both the subnet and for the network as a whole. A different approach to network construction can be thought of as subnetting in reverse. Known as CIDR, or Classless Inter-Domain Routing, this approach also creates a series of subnetworks. Rather than dividing an existing network into small components, CIDR takes smaller components and connects them into a larger network. This can often be the case when a business is acquired by a larger corporation. Instead of doing away with the network developed and used by the newly acquired business, the corporation chooses to continue operating that network as a subsidiary or an added component of the corporation's network. In effect, the system of the purchased entity becomes a subnet of the parent company's network. IP Distribution - This is a generic term which could mean distribution of content over an IP network or distribution of IP addresses within a Company. Sometimes people will refer to this as Internet Protocol address management (IPAM) is a means of planning, tracking, and managing the Internet Protocol address space used in a network. Most commonly, tools such as DNS and DHCP are used in conjunction as integral functions of the IP address management function, and true IPAM glues these point services together so that each is aware of changes in the other (for instance DNS knowing of the IP address taken by a client via DHCP, and updating itself accordingly). Additional functionality, such as controlling reservations in DHCP as well as other data aggregation and reporting capability, is also common. IPAM tools are increasingly important as new IPv6 networks are deployed with larger address pools, different subnetting techniques, and more complex 128-bit hexadecimal numbers which are not as easily human-readable as IPv4 addresses. Reference(s) used for this question: STREBE, Matthew and PERKINS, Charles, Firewalls 24seven, Sybex 2000, Chapter 1: Understanding Firewalls. Schneiter, Andrew (2013-04-15). Official (ISC)2 Guide to the CISSP CBK, Third Edition : Telecommunications and Network Security, Page 350. Harris, Shon (2012-10-25). CISSP All-in-One Exam Guide, 6th Edition (Kindle Locations 12765-12774). Telecommunications and Network Security, Page 604-606 http://searchnetworking.techtarget.com/definition/Port-Address-Translation-PAT http://en.wikipedia.org/wiki/IP_address_spoofing http://www.wisegeek.com/what-is-subnetting.htm http://en.wikipedia.org/wiki/IP_address_management
