Chapter 3: Cryptography Flashcards
What is the term for when a partially correct key is useless to an attacker?
Confusion
What is the concept where known-plaintext isn’t useful in decoding the entire plaintext?
Diffusion
What is the concept for when ciphertext doesn’t repeat, even when the plaintext repeats
Semantic security
What is an arbitrary number that can be used along with a secret key for data encryption. Also called a nonce because it can only be used once. It does not have to be secret
Initialization Vector (IV)
What are the popular symmetric algorithms (5)
AES 3DES/TDES Blowfish Twofish Rivest Cipher
What are the popular block cypher modes (7)
Electronic Code Book Mode (ECB) Cipher Block Chaining Mode (CBC) Cipher Feedback Mode (CFB) Output Feedback Mode (OFB) Counter Mode (CTR) Galois Counter Mode (GCM) Offset Codebook Mode (OCB)
What are the popular asymmetric algorithms (4)
RSA
DSA
ECC
DH
What are the popular hashing algorithms (5)
MD5 SHA-1 SHA-2 SHA-3 RIPEMD
What are the popular password storage algorithms (3)
NTLM
bcrypt
PBKDF2
What is the most widely used Rivest Cipher
RC4
Which symmetric algorithms are considered secure (3)
AES
Twofish
RC6
What are the key sizes that AES and Twofish use (3)
128, 192 or 256-bits
What is the term for using constantly changing keys
ephemeral keys
What is the concept for when, if a public key is lost, it is of no use to recover ephemeral keys used in past sessions
Perfect Forward Secrecy
Which block cipher mode is simplest, but does not offer semantic security
Electronic Code Book Mode (ECB)
In which block cypher mode can corruption of earlier cyphertext can prevent decryption of future block
Cypher Block Chaining Mode (CBC)
Cipher Feedback Mode (CFB)
Which block cypher mode is like CFB, but the keystream is generated independently of previous cyphertext
Output Feedback Mode (OFB)
Which block cypher mode is where each block’s encryption uses a successively incrementing counter
Counter Mode (CTR)
Which block cypher mode combines Counter mode with a hash-based authentication code (HMAC), which prevents against chosen cyphertext attacks? It works on 128 bit blocks, which makes it popular for AES, but doesn’t work on 3DES and Blowfish
Galois Counter Mode (GCM)
Which block cypher mode is supported by WPA3 Enterprise wiresless
Galois Counter Mode (GCM)
Which block cypher mode applies MAC and encryption in a single pass, which increases performance, and is simple to use. However, it is under patent protection, making it harder to use than the open standards?
Offset Codebook Mode (OCB)
Which asymmetric algorithm has a key as large as 4096, is often used for symmetric key exchange, and is the default algorithm for SSL/TLS certificates?
RSA
Which asymmetric algorithm uses a different one-way problem called a discrete logarithm. It has a strength similar to RSA, but can be faster for some applications. The default 1024 bit key length is no longer considered secure?
Digital Signature Algorithm (DSA)
Which asymmetric algorithm is based off the difficulty of calculated specific properties of elliptical curves, stronger with shorter keys, and is primarily used in phones?
Elliptic Curve Cryptography (ECC)
