Monday, August 15, 2016

CS6701 Cryptography and Network Security Unit 1 Two Marks with Answer

Anna University Chennai Question Bank
CS6701- Cryptography & Network Security
7th Semester
First Assessment Test – Two Marks – Question & Answer

1. What are Active Attacks?
Active attacks involve some modification of the data stream or the creation of a false stream. It can be subdivided into four categories.
(i) Masquerade (ii) Replay
(iii) Modification of messages (iv) Denial of Service (DoS)

2. What are Passive Attacks?
Passive attacks are in the nature of eavesdropping on, or monitoring of transmissions. The goal of the opponent is to obtain information that is being transmitted. Two types of passive attacks are
(i) Release of message contents
(ii) Traffic Analysis

3. What are the essential ingredients of Symmetric Cipher?
A symmetric encryption scheme has five ingredients.
(i) Plain Text (ii) Encryption algorithm
(iii) Secret Key (iv) Cipher text
(v) Decryption algorithm

4. What is meant by Denial of Service (DoS)?
The denial of service(DoS) is an active attack that prevents or inhibits the normal use or management of communications facilities. This attack may have a specific target, for example, an entity may suppress all messages directed to a particular destination. Another form of service denial is the disruption of an entire network either by disabling the network or by overloading it with messages so as to degrade performance.

5. What is Brute-force attack?
The attacker tries every possible key on a piece of cipher text until an intelligible translation into plain text is obtained. On average, half of possible keys must be tried to achieve success.

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1 comment:

  1. hi. i need cns two mark ith answer for 5 units plz sent me


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