Correct Answer: A

A photoelectric sensor does not "directly" sense motion there is a narrow beam that won't set off the sensor unless the beam is broken. Photoelectric sensors, along with dry contact switches, are a type of perimeter intrusion detector.

All of the other answers are valid types of motion detectors types. The content below on the different types of sensors is from Wikepedia: Indoor Sensors

These types of sensors are designed for indoor use. Outdoor use would not be advised due to false alarm vulnerability and weather durability.Passive infrared detectors

Passive Infrared Sensor

The passive infrared detector (PIR) is one of the most common detectors found in household and small business environments because it offers affordable and reliable functionality. The term passive means the detector is able to function without the need to generate and radiate its own energy (unlike ultrasonic and microwave volumetric intrusion detectors that are "active" in operation). PIRs are able to distinguish if an infrared emitting object is present by first learning the ambient temperature of the monitored space and then detecting a change in the temperature caused by the presence of an object. Using the principle of differentiation, which is a check of presence or nonpresence, PIRs verify if an intruder or object is actually there. Creating individual zones of detection where each zone comprises one or more layers can achieve differentiation. Between the zones there are areas of no sensitivity (dead zones) that are used by the sensor for comparison.

Ultrasonic detectors

Using frequencies between 15 kHz and 75 kHz, these active detectors transmit ultrasonic sound waves that are inaudible to humans. The Doppler shift principle is the underlying method of operation, in which a change in frequency is detected due to object motion. This is caused when a moving object changes the frequency of sound waves around it. Two conditions must occur to successfully detect a Doppler shift event:

There must be motion of an object either towards or away from the receiver. The motion of the object must cause a change in the ultrasonic frequency to the receiver relative to the transmitting frequency.

The ultrasonic detector operates by the transmitter emitting an ultrasonic signal into the area to be protected. The sound waves are reflected by solid objects (such as the surrounding floor, walls and ceiling) and then detected by the receiver. Because ultrasonic waves are transmitted through air, then hard-surfaced objects tend to reflect most of the ultrasonic energy, while soft surfaces tend to absorb most energy.

When the surfaces are stationary, the frequency of the waves detected by the receiver will be equal to the transmitted frequency. However, a change in frequency will occur as a result of the Doppler principle, when a person or object is moving towards or away from the detector. Such an event initiates an alarm signal. This technology is considered obsolete by many alarm professionals, and is not actively installed.

Microwave detectors

This device emits microwaves from a transmitter and detects any reflected microwaves or reduction in beam intensity using a receiver. The transmitter and receiver are usually combined inside a single housing (monostatic) for indoor applications, and separate housings (bistatic) for outdoor applications. To reduce false alarms this type of detector is usually combined with a passive infrared detector or "Dualtec" alarm.

Microwave detectors respond to a Doppler shift in the frequency of the reflected energy, by a phase shift, or by a sudden reduction of the level of received energy. Any of these effects may indicate motion of an intruder.

Photo-electric beams

Photoelectric beam systems detect the presence of an intruder by transmitting visible or infrared light beams across an area, where these beams may be obstructed. To improve the detection surface area, the beams are often employed in stacks of two or more. However, if an intruder is aware of the technology's presence, it can be avoided. The technology can be an effective long- range detection system, if installed in stacks of three or more where the transmitters and receivers are staggered to create a fence-like barrier. Systems are available for both internal and external applications. To prevent a clandestine attack using a secondary light source being used to hold the detector in a 'sealed' condition whilst an intruder passes through, most systems use and detect a modulated light source. Glass break detectors

The glass break detector may be used for internal perimeter building protection. When glass breaks it generates sound in a wide band of frequencies. These can range from infrasonic, which is below 20 hertz (Hz) and can not be heard by the human ear, through the audio band from 20 Hz to 20 kHz which humans can hear, right up to ultrasonic, which is above 20 kHz and again cannot be heard. Glass break acoustic detectors are mounted in close proximity to the glass panes and listen for sound frequencies associated with glass breaking. Seismic glass break detectors are different in that they are installed on the glass pane. When glass breaks it produces specific shock frequencies which travel through the glass and often through the window frame and the surrounding walls and ceiling. Typically, the most intense frequencies generated are between 3 and 5 kHz, depending on the type of glass and the presence of a plastic interlayer. Seismic glass break detectors "feel" these shock frequencies and in turn generate an alarm condition.

The more primitive detection method involves gluing a thin strip of conducting foil on the inside of the glass and putting low-power electrical current through it. Breaking the glass is practically guaranteed to tear the

foil and break the circuit.

Smoke, heat, and carbon monoxide detectors

Heat Detection System

Most systems may also be equipped with smoke, heat, and/or carbon monoxide detectors. These are also known as 24 hour zones (which are on at all times). Smoke detectors and heat detectors protect from the risk of fire and carbon monoxide detectors protect from the risk of carbon monoxide. Although an intruder alarm panel may also have these detectors connected, it may not meet all the local fire code requirements of a fire alarm system. Other types of volumetric sensors could be:

Active Infrared

Passive Infrared/Microware combined

Radar

Accoustical Sensor/Audio

Vibration Sensor (seismic)

Air Turbulence

Correct Answer: A

In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a left shift of 3, D would be replaced by A, E would become B, and so on. The method is named after Julius Caesar, who used it in his private correspondence.

The encryption step performed by a Caesar cipher is often incorporated as part of more complex schemes, such as the Vigenère cipher, and still has modern application in the ROT13 system. As with all single alphabet substitution ciphers, the Caesar cipher is easily broken and in modern practice offers essentially no communication security.

The following answer were incorrect:

The Jefferson disk, or wheel cipher as Thomas Jefferson named it, also known as the Bazeries Cylinder, is a cipher system using a set of wheels or disks, each with the 26 letters of the alphabet arranged around their edge. The order of the letters is different for each disk and is usually scrambled in some random way. Each disk is marked with a unique number. A hole in the centre of the disks allows them to be stacked on an axle. The disks are removable and can be mounted on the axle in any order desired. The order of the disks is the cipher key, and both sender and receiver must arrange the disks in the same predefined order. Jefferson's device had 36 disks.

An Enigma machine is any of a family of related electro-mechanical rotor cipher machines used for the encryption and decryption of secret messages. Enigma was invented by the German engineer Arthur Scherbius at the end of World War I. The early models were used commercially from the early 1920s, and adopted by military and government services of several countries. Several different Enigma models were produced, but the German military models are the ones most commonly discussed.

SIGABA: In the history of cryptography, the ECM Mark II was a cipher machine used by the United States for message encryption from World War II until the 1950s. The machine was also known as the SIGABA or Converter M-134 by the Army, or CSP-888/889 by the Navy, and a modified Navy version was termed the CSP-2900. Like many machines of the era it used an electromechanical system of rotors in order to encipher messages, but with a number of security improvements over previous designs. No successful cryptanalysis of the machine during its service lifetime is publicly known.

Reference(s) used for this question:

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

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

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

Correct Answer: C

Each Class B network address has a 16-bit network prefix, with the two highest order bits set to 1-0.

The following answers are incorrect:

The first bit of the IP address would be set to zero. Is incorrect because, this would be a Class A network

address.

The first two bits of the IP address would be set to one, and the third bit set to zero. Is incorrect because,

this would be a Class C network address.

The first three bits of the IP address would be set to one. Is incorrect because, this is a distractor. Class D

and E have the first three bits set to 1. Class D the 4th bit is 0 and for Class E the 4th bit to 1.

Classless Internet Domain Routing (CIDR)

High Order bits are shown in bold below.

For Class A, the addresses are 0.0.0.0 - 127.255.255.255

The lowest Class A address is represented in binary as 00000000.00000000.0000000.00000000

For Class B networks, the addresses are 128.0.0.0 - 191.255.255.255.

The lowest Class B address is represented in binary as 10000000.00000000.00000000.00000000

For Class C, the addresses are 192.0.0.0 - 223.255.255.255

The lowest Class C address is represented in binary as 11000000.00000000.00000000.00000000 For

Class D, the addresses are 224.0.0.0 - 239.255.255.255 (Multicast)

The lowest Class D address is represented in binary as 11100000.00000000.00000000.00000000

For Class E, the addresses are 240.0.0.0 - 255.255.255.255 (Reserved for future usage)

The lowest Class E address is represented in binary as 11110000.00000000.00000000.00000000

Classful IP Address Format

References: 3Com http://www.3com.com/other/pdfs/infra/corpinfo/en_US/501302.pdf AIOv3 Telecommunications and Networking Security (page 438)

Correct Answer: D

Twisted Pair cables currently have two categories in common usage. CAT3 and CAT5.

Source: KRUTZ, Ronald L. and VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley and Sons, Page 72.

Correct Answer: D

Packet filtering is used in the first generation of firewalls and does not keep track of the state of a

connection. Stateful packet filtering does.

Source: WALLHOFF, John, CISSP Summary 2002, April 2002, CBK#2 Telecommunications and Network

Security (page 6)