E CES 212 81 Actual Questions and Correct Answers
Q1
Trying every possible key to break a cipher. For many types of encryption this is completely
impractical because of the amount of time it would take to try every possible key.
Answer: Brute Force
Q2
Using a method (other than brute force) to derive the key of a cipher. In some cases
cryptographic techniques can be used to test the efficacy of a cryptographic algorithm.
Frequently used to test hash algorithms for collisions.
Answer: Cryptanalysis
Q3
The most basic tool for breaking most classical ciphers. Not effective against modern ciphers.
Answer: Frequency Analysis
Q4
An attack that is particularly successful against block ciphers based on substitution-permutation
networks. For a block size b, holds b-k bits constant and runs the other k
Answer: successful against block ciphers based on substitution-permutation
Q5
A cryptanalysis success where the attacker gains some Shannon information about plain texts
(or cipher texts) not previously known. Information Deduction (Cryptanalysis Success)
Answer: information about plain texts (or
Q1
Trying every possible key to break a cipher. For many types of encryption this is completely
impractical because of the amount of time it would take to try every possible key.
Answer: Brute Force
Q2
Using a method (other than brute force) to derive the key of a cipher. In some cases
cryptographic techniques can be used to test the efficacy of a cryptographic algorithm.
Frequently used to test hash algorithms for collisions.
Answer: Cryptanalysis
Q3
The most basic tool for breaking most classical ciphers. Not effective against modern ciphers.
Answer: Frequency Analysis
Q4
An attack that is particularly successful against block ciphers based on substitution-permutation
networks. For a block size b, holds b-k bits constant and runs the other k
Answer: successful against block ciphers based on substitution-permutation
Q5
A cryptanalysis success where the attacker gains some Shannon information about plain texts
(or cipher texts) not previously known. Information Deduction (Cryptanalysis Success)
Answer: information about plain texts (or
