MOD 11 QUIZ - Cryptography Flashcards
What is Cryptology?
Cryptography plus cryptoanalysis
What are Block Ciphers?
Operate on chunks of a message
After encryption has been applied, what is the message called?
Ciphertext
What are crypto variables also called?
Keys
What are Stream Ciphers?
Operate one bit at a time
When a message has not been encrypted, what is it called?
Plaintext
What are Message Digests?
Summaries of a message’s content produced by a hashing algorithm
Codes work on ________, ciphers work on ___________.
phrases, individual characters
What do Symmetric Key Algorithms rely on?
A shared secret
What is the term used to describe when a single change in the plaintext causes multiple changes spread throughout the ciphertext?
Diffusion
What is the primary weakness for Symmetric Key Algorithms?
Key distribution
What is a Nonce?
A random number
What is the principle that states, “A cryptographic system should be secure even if everything about the system, except the key, is public knowledge.”
Kerckhoff’s
What makes One-Time Pads so powerful?
They use a different substitution alphabet for each letter
What is the bit size for a cryptographic algorithm?
Number of bits in each key
What is the primary weakness of Asymmetric Key Algorithms?
What is a one-way function?
A mathematical operation that easily produces output, but makes retrieval of input values impossible
What are the goals of Cryptography?
Nonrepudiation
Integrity
Confidentiality
What is CBC?
Cipher Block Chaining
What is nonrepudiation?
Ensures the message was originated by sender
