MODULE 2 Flashcards
Symmetric encryption ingredients:
- Plaintext
- Encryption algorithm
- Secret key
- Ciphertext
- Decryption algorithm
Cryptanalysis types of attacks:
- Ciphertext only
- Known plaintext
- Chosen plaintext
- Chosen ciphertext
- Chosen text
Encryption is computationally secure if:
- Cost of breaking cipher exceeds info value
- Time to break cipher exceeds info useful lifetime
Feistel cipher design features:
- Block size
- Key size
- Number of rounds
- Ease of analysis
- Function
- Fast encryption/decryption
- Subkey generation algorithm
AES:
An encryption standard that processes a block as a matrix each round
Design considerations for stream ciphers:
- Encryption sequence must have a large period
- Keystream approximate true random number
- A key length of at least 128 bits is desirable
RC4:
A stream cipher with variable key size and byte-oriented operations for random permutations
WEP stands for _____
Wired Equivalent Privacy
WPA stands for _____
Wi-Fi Protected Access
ECB stands for _____
Electronic Codebook
RC4’s practical uses:
- SSL/TLS
- WEP/WPA
CBC stands for _____
Cipher Block Chaining
CFB stands for _____
Cipher Feedback
CTR stands for _____
Counter
OFB stands for _____
Output Feedback
Message authentication:
Verifying that a received message is authentic to protect against active attacks
Block cipher modes of operation:
- ECB
- CBC
- CFB
- OFB
- CTR
Confidentiality of RSA depends on a number of factors:
- Algorithm security
- Private key security
- Protocol security
Aspects of authentic messages:
- Contents unaltered
- From authentic source
- Timely and in correct sequence
SHA-512 algorithm processing steps:
- Append padding
- Append length
- Initialize buffer
- Process message
- Output
Hash function requirements:
- Easy to compute
- Any size input
- Fixed-length output
- One-way property
- Weak collision resistance
- Strong collision resistance
Attack approaches against hash functions:
- Cryptanalysis
- Brute-force attack
Timing attacks are alarming because:
- Unexpected
- Ciphertext only
Digital signature:
Cryptographic transformation of data that provides origin authentication, data integrity, and signatory non-repudiation
Requirements to qualify as random:
- Randomness
- Unpredictability
