IT 223 Lecture 8
brute force attack
A cryptography attack that tries every possible key value.
Algorithms
A defined sequence of operations.
Ciphers
A process for concealing the meaning of a message or a message concealed by such a process.
In cryptography, what is a cipher most often referring to?
Algorithm for performing encryption and decryption.
Public-key Cryptography (PKC)
Another name for Asymmetric Cryptography
Statistical Analysis
Attempting to find non-random patterns in intercepted cipher text that might reveal the plaintext, or even the key.
Exploiting public data
Attempting to learn private data by analyzing public data related to it.
Social engineering
Attempting to trick a user into revealing a key.
Which of the following Boolean operations is typically used in encryption algorithms?
Bitwise XOR
Symmetric Cryptography Pros
Confidentiality, Authentication of Origin, Authentication of Integrity
Asymmetric Cryptography Pros
Confidentiality, Authentication of Origin, Non-repudiation
Which of the following is/are enabled or provided by Cryptography?
Confidentiality, Authentication, Non-repudiation
___ is the process of attempting to defeat cryptographic systems.
Cryptanalysis
The transformation of meaningful data into something else is called ____.
Cryptography
Side-channel Analysis
Involves measuring some side-effect of the encryption/decryption to learn some or all the bits in the key.
Transposition
Is a fundamental type of operation that is performed in encryption or decryption. Involves rearranging the sequence of a set of values without altering each one. (other than its place in the sequence).
Substitution
Is a fundamental type of operation that is performed in encryption or decryption. Involves replacing a data value with another according to some rule.
Decryption
Is a process that converts ciphertext back into plaintext.
Encryption
Is a process that converts plaintext into meaningless data called ciphertext.
Codes
Is a system for representing data using a set of symbols.
Dictionary attack
Limits the set of keys to be tested to those likely to be chosen by typical users.
Which of the following uses both substitution and transposition operations? Decryption, Encryption, Product Cipher, Cryptoanalysis
Product Cipher
Which of the following is a transposition operation? Boolean operations, rotations, table lookup, variable replacement
Rotations
Symmetric Algorithms key size
moderate key length
Product Cipher
uses both substitution and transposition operations.
The cipertext produced depends on which of the following?
The plaintext, encryption process, and the key value.
The ciphertext produced during the encryption process depends on:
The plaintext, the encryption process, the key value.
Cryptography
The transformation of meaningful data into something else and vice versa.
___ involves rearranging the sequence of a set of values without altering each one .
Transposition
Brute force attack involves trying every possible key value to decrypt the intercepted ciphertext until the output seems to be valid plaintext. True or False?
True
Quantum Cryptography
Uses photons that represent 1's and 0's to transmit a key.
Quantum computing
Using a quantum computer to crack a cryptosystem.
Asymmetric Algorithms key size
Very long key length
Hybrid Solution
Where a one-time key value (called a session key) is encrypted asymmetrically with a recipients public key and a message is encrypted symmetrically with that key value.
Asymmetric Cryptography
The decryption process is NOT the equal and opposite of the encryption process, meaning it does NOT use the inverse operations in the reverse sequence of each cycle of decryption. There are 2 keys, a public and private key. One encrypts and the other decrypts.
Symmetric Cryptography
The decryption process is the equal and opposite of the encryption process, meaning it uses the inverse operations in the reverse sequence for each cycle of decryption. The same key is used in encryption and decryption.
