6. Assume the length of salt is 8 bits and the dictionary for dictionary attack contain 300 words. Calculate the search space for attacking salted passwords. Give an exact number.
Ans:
7. Assume receiver B received a signed document from sender A under the digital signature on the document?
A’s public key, B’s public key, A’s private key, B’s private key
8. ________ refer to technique involving the use of human insiders to circumvent computer.
9. Encrypt “SECURITY” using Caesar cipher with k=4.
Ans:
10. which of the following attacks can harm confidentially. Choose all that apply:
Alternation, Repudiation, Masquerading, Eavesdropping, Denial- of-service
11. The output of the cryptographic hashing is called message digest.
True/False
12. Connect each of the security principles to the most relevant keyword.
___ No bypass. 1. Psychological acceptability.
___ Logging(auditing) 2. Compromise recording
___User interfaces. 3. Economy of mechanism
___Simplicity 4. Complete mediation
6.
Length of the salt = 8 bits
Total possible salts = 28 = 64
Size of dictionary = 300 words
Size of the search space = 64 x 300 = 19200
7.
The digital signature is signed using A's private key
8.
Insider Attack
9.
The given plaintext is SECURITY
k=4
The ciphertext will be
( 18 + 4 ) mod 26 = 22 = w
( 4 + 4 ) mod 26 = 8 = i
( 2 + 4 ) mod 26 = 6 = g
( 20 + 4 ) mod 26 = 24 = y
( 17 + 4 ) mod 26 = 21 = v
( 8 + 4 ) mod 26 = 12 = m
( 19 + 4 ) mod 26 = 23 = x
( 24 + 4 ) mod 26 = 2 = c
So the ciphertext is wigyvmxc
10.
Eavesdropping harms confidentiality
11.
True
12.
No bypass------------Psychological acceptability.
Logging---------------Compromise recording
User interfaces-----Economy of mechanism
Simplicity------------Complete mediation
6. Assume the length of salt is 8 bits and the dictionary for dictionary attack contain...