The writing Module

THE SPEAKING MODULE

After text activity

IV. Reading Exercises:

Exercise 1. Read and memorize using a dictionary:

Unforgeable, technique, to derive, random sequence, to memorize, digraph, wiretrapper, to intercept, forgery, tampering, approach, vice virsa

Exercise 2. Answer the questions:

1) What defects do passwords have as a general technique?

2) Why do some systems have programs that generate random sequences of letters for use as passwords?

3) What alternative approach to secrecy it there?

4) What common problem do password and the unforgeable object approaches have?

5) What easy way for an intruder to penetrate a password system is there?

Exercise 4. Match the left part with the right:

1 The primary weakness of such schemes is that the hard-to-fabricate object is reduced to	a) sequences a secret after all.
2. It is relatively easy for an intruder to	b) a stream of bits to be transmitted to the computer.
3. It may be necessary to make the acceptable bit	c) modify the terminal to transmit any sequence of bits he chooses.
4. A second significant defect is that	d) the password must be exposed to be used.

II. Speaking Exercises:

Exercise 1. Define the terms using the suggested words and expressionsas in example:

Information science	Forgery	Bit	Sequence
discipline, deals with, processes, storing, transferring, information	producing, copy, document, signature, banknote, work of art	smallest, unit, information, computer's, memory	Particular, order, which, things, happen, are arranged

EXAMPLE: Information science is a discipline that deals with the processes of storing and transferring information.

Exercise 2. Ask questions to the given answers:

1) Question: ___________________________________________?

Answer: In one recent study of some 300 self-chosen passwords on a typical time-sharing system, more than 50 percent were found to be short enough to guess by exhaustion, derived from the owner's name, or something closely associated with the owner, such as his telephone number or birth date.

2) Question: ___________________________________________?

Answer: After receiving the password, the masquerader gracefully terminates the communication with some unsurprising error message, and the caller may be unaware that his password has been stolen.

3) Question: ___________________________________________?

Answer: This computer can be programmed to "masquerade," that is, to act just like the system the caller intended to use, up to the point of requesting him to type his password.

Writing exercises:

Exercise 1. Fill in the gaps with the suggested words:

plastic,approach, transmits, given, input, code

An alternative______ to secrecy is unforgeability. The user is _______a key, or magnetically striped _______card, or some other unique and relatively difficult-to-fabricate object. The terminal has an ______device that examines the object and ________its unique identifying code to the computer system, which treats the_______ as a password that need not be kept secret.

Exercise 2. Compose a story on one of the topics (up to 100 words):

1) Password as a general technique of secrecy

2) Different approaches to secrecy and their defects

Lesson 5

Дата добавления: 2015-08-31