Chapter 2 Study guide Flashcards
DES
- 56 bit key
- 64 bit block size
Diffie-Helmen method
- First method for key exhange using a one-way function
- Vulnerable to man-in-the-middle attacks
MD5
128 bit hash
RC4
- Streaming cipher used in SSL and WEP
- 40 bit key
RC5
- Block encryption
- variable key size
- 32, 64, or 128 block sizes
3-DES
Uses DES 1, then DES key 2, then DES key 1 again. This equals 112 bit key size (double DES). 64 bit block size
SHA-1
160-bit hash
SHA-256
256-bit hash
Integrity Check
Hashes are used to preform integrity checks.
by rehashing the output and comparing it to the original hash value to ensure nothing has been changed..
Streaming encryption products
RC4 and ChaCha
Block encryption products
RC5, IDEA, DES, 3-DES, AES, Blowfish and Twofish
AES
- block encryption
- 128, 192, or 256-bit key sizes
- 128 block size
X-OR
compares two binary numbers and creates a new one.
padding
The extra bits used to fill out the rest of an encryption.
Uses ASCII. If you have 128 bit block encryption but only 120 bits to encrypt then padding fills the 8 bits.
PKCS#5
Standard used for password based encryption
PKCS#7
Standard used to sign and/or encrypt messages for PKI
PKCS#10
Cyber Block Chaining (CBC)
Salts the first block and then uses that output to encrypt the following blocks. This is used to change outputs.
Cipher Feedback (CFB)
Takes a block and turns it into a stream cipher. Similar to CBC in process.
Output Feedback (OFB)
Synchronous stream using X-OR
Counter Mode (CTR)
Generates a counter value and a nonce
What are the rounds for the 3 key encryption types for AES?
128-bit -> N=10 rounds
192-bit -> N=12 rounds
256-bit -> N=14 rounds
Skipjack
Uses Clipper Chip - 80-bit key, 60 bit block
Blowfish
- 128, 192, 256 bit encryption key
- 64 Bit Blocks
- Memorization:
- Blowfish is half of Twofish. A blow
Blowfish is one fish. - This helps allot, especially once you learn
the CART/CARBT method
- Blowfish is half of Twofish. A blow
