Chapter 6 Flashcards
What principle states that a cryptographic system should be secure even if everything about the system, except the key, is public knowledge.
Kerckhoff’s Principle/Assumption
What standard defines the hardware and software requirements for cryptographic modules that the federal gov uses?
FIPS 140-2
What boolean mathmatics operation has the “^” symbol, where the X and Y values are true only in columns where both X & Y are true.
AND
What boolean operation has the “v” symbol and only returns false when both input values are false.
OR
What boolean operation has the “~” and reverses the input values for only one variable at a time?
NOT
What boolean operation has the “⊕” and returns a true value when only one of the input values is true.
XOR
What mathmatical operation easily produces output values for each possible combination of inputs but makes it impossible to retrieve the input values.
One-Way Function
What type of cryptosystem are all based on some type of one-way function?
Public Key Cryptosystems
What is considered a nonce and is a random number that acts as a placeholder variable in mathematical functions.
IV
What describes a cryptographic key being stored with a third party known as a recovery agent and when certain conditions are met, the recovery agent restores an authorized user’s access or decrypt the material themselves.
Key Escrow
What type of attack is a Ceasar cipher vulnerable to?
Frequency Analysis
What technique protects against direct frequency analysis but is vulnerable to period analysis.
Polyalphabetic Substitution
What attack is an examination of frequency based on the repeated use of the key?
Period Analysis
What cipher is as long as the message itself and is often chosen from a common book, newspaper, or magazine?
Running Key Cipher
What describes the change in the plaintext resulting in multiple changes spread throughout the ciphertext?
Diffusion
What type of secret key exist only for a single session and is commonly used by the TLS protocol.
Ephemeral Key
What are the major weaknesses with symmetric key cryptography?
Key distribution is a major problem
Does not implement non-repudiation
Isn’t scalable
Must be generated often
How many symmetric keys do you need for communication between 5 participants?
10
How many symmetric keys do you need for communication between 3 participants?
3
How many symmetric keys do you need for communication between 2 participants?
1
How many symmetric keys do you need for communication between 10 participants?
45
How many symmetric keys do you need for communication between 100 participants?
4,950
How many asymmetric keys do you need for communication between 5 participants?
10
How many asymmetric keys do you need for communication between 10 participants?
20
