IFT 202 - Module 7 Overview Questions
with complete solution 2025
Communication - correct answer Sender Receiver Medium Message
Cryptography - correct answer Secret Writing - A method of concealing data
against unauthorized access.
Hiding data in plain sight through a transformation process. Using complex
mathematical algorithms.
Only specific parties can reverse the transformation.
Encryption - correct answer Converting a plaintext message into ciphertext.
Decryption - correct answer Converting ciphertext into a plaintext message.
State of Data - correct answer Data at rest
Can be encrypted.
Data in transit
Can be encrypted.
Data in use
Can not be encrypted.
Must be decrypted first.
Cryptosystem Elements - correct answer Plaintext (P)
, Key (K)
Encryption algorithm (E)
Ciphertext (C)
Decryption algorithm (D)
Cryptography Concepts - correct answer C = E(K,P)
P = D(K,C)
Cryptographic Primitives - correct answer Substitution cipher - replace
Sophistication - Confusion
Each bit of the ciphertext should depend on several parts of the key.
Hides relationship between the ciphertext and key.
Cryptographic Primitives - correct answer Transposition cipher - rearrange
Sophistication - Diffusion
Changing a single bit of plaintext would change approximately half of the bits
in the ciphertext and vise versa.
Good Cryptography - correct answer 1. Simple to implement/use.
2. Reliable (error free)
3. Based on sound mathematics.
4. Attacked and analyzed by experts who have deemed it to be strong.
5. Strong = if there is no better attack than brute force.
6. Stood the test of time.
with complete solution 2025
Communication - correct answer Sender Receiver Medium Message
Cryptography - correct answer Secret Writing - A method of concealing data
against unauthorized access.
Hiding data in plain sight through a transformation process. Using complex
mathematical algorithms.
Only specific parties can reverse the transformation.
Encryption - correct answer Converting a plaintext message into ciphertext.
Decryption - correct answer Converting ciphertext into a plaintext message.
State of Data - correct answer Data at rest
Can be encrypted.
Data in transit
Can be encrypted.
Data in use
Can not be encrypted.
Must be decrypted first.
Cryptosystem Elements - correct answer Plaintext (P)
, Key (K)
Encryption algorithm (E)
Ciphertext (C)
Decryption algorithm (D)
Cryptography Concepts - correct answer C = E(K,P)
P = D(K,C)
Cryptographic Primitives - correct answer Substitution cipher - replace
Sophistication - Confusion
Each bit of the ciphertext should depend on several parts of the key.
Hides relationship between the ciphertext and key.
Cryptographic Primitives - correct answer Transposition cipher - rearrange
Sophistication - Diffusion
Changing a single bit of plaintext would change approximately half of the bits
in the ciphertext and vise versa.
Good Cryptography - correct answer 1. Simple to implement/use.
2. Reliable (error free)
3. Based on sound mathematics.
4. Attacked and analyzed by experts who have deemed it to be strong.
5. Strong = if there is no better attack than brute force.
6. Stood the test of time.
