INFORMATION NETWORK AND SECURITY - PART 1
Q. Define block cipher?
A. A block cipher is a method of encrypting data in blocks to produce ciphertext
using a cryptographic key and algorithm.
Q. What is Fiestel cipher?
A. The Feistel cipher is a design model or structure used to build various
symmetric block ciphers, such as DES.
Q. List out any two virus countermeasures.
A. personal firewalls.
application firewalls.
anti-virus software.
pop-up blockers.
Q. List out the functions used for rounds of AES?
A. (1) byte substitution, (2) shift rows, (3) mix columns, and (4) add round key.
Q. Define Honeypot.
A. In computer terminology, a honeypot is a computer security mechanism set to
detect, deflect, or counteract attempts at unauthorized use of information
systems
1
, Q. List and explain different categories of security services
A. Message Confidentiality − The principle of confidentiality defines that only the
sender and the intended recipient should be capable to create the element of the
message. It protects the transmitted data from passive attack.
onnection Confidentiality − The protection of all user information on a
C
connection.
onnectionless Confidentiality − The security of all user data in an individual data
C
block.
T raffic-flow Confidentiality − The protection of the information that can be
derived from observation of traffic flows.
ccess Control − The principle of access control decides who should be capable to
A
access information or system through communication link. It supports the
avoidance of unauthorized use of a resource
Q. Explain Vigenere cipher giving proper example.
A. Vigenere Cipher is an encryption and decryption algorithm. It is a type of
polyalphabetic substitution cipher, which means that the cipher alphabet is
changed regularly during the encryption process. Due to this, the cipher becomes
less vulnerable to cryptanalysis.The Vigenere Cipher was developed in 1585 by
Blaise de Vigenere. He used a Vigenere table or square to encode messages.
Input : Plaintext : GEEKSFORGEEKS
Keyword : AYUSH
Output : Ciphertext : GCYCZFMLYLEIM
For generating key, the given keyword is repeated
2
Q. Define block cipher?
A. A block cipher is a method of encrypting data in blocks to produce ciphertext
using a cryptographic key and algorithm.
Q. What is Fiestel cipher?
A. The Feistel cipher is a design model or structure used to build various
symmetric block ciphers, such as DES.
Q. List out any two virus countermeasures.
A. personal firewalls.
application firewalls.
anti-virus software.
pop-up blockers.
Q. List out the functions used for rounds of AES?
A. (1) byte substitution, (2) shift rows, (3) mix columns, and (4) add round key.
Q. Define Honeypot.
A. In computer terminology, a honeypot is a computer security mechanism set to
detect, deflect, or counteract attempts at unauthorized use of information
systems
1
, Q. List and explain different categories of security services
A. Message Confidentiality − The principle of confidentiality defines that only the
sender and the intended recipient should be capable to create the element of the
message. It protects the transmitted data from passive attack.
onnection Confidentiality − The protection of all user information on a
C
connection.
onnectionless Confidentiality − The security of all user data in an individual data
C
block.
T raffic-flow Confidentiality − The protection of the information that can be
derived from observation of traffic flows.
ccess Control − The principle of access control decides who should be capable to
A
access information or system through communication link. It supports the
avoidance of unauthorized use of a resource
Q. Explain Vigenere cipher giving proper example.
A. Vigenere Cipher is an encryption and decryption algorithm. It is a type of
polyalphabetic substitution cipher, which means that the cipher alphabet is
changed regularly during the encryption process. Due to this, the cipher becomes
less vulnerable to cryptanalysis.The Vigenere Cipher was developed in 1585 by
Blaise de Vigenere. He used a Vigenere table or square to encode messages.
Input : Plaintext : GEEKSFORGEEKS
Keyword : AYUSH
Output : Ciphertext : GCYCZFMLYLEIM
For generating key, the given keyword is repeated
2
