Crypto Flashcards
Name five services that cryptosystems can provide:
1 Confidentiality 2 Integrity 3 Authentication 4 Authorization (Upon proving identity, the individual is provided with a key or password that will allow access to some other resource.) 5 Nonrepudiation
The method of embedding a message into some types of media (stenography) is to use the LSB. What does LSB stand for?
Least-significant bit
Which of the following are examples of asymmetric algorithms? (You can choose more than one.)
A. DES
B. RC4
C. ECC
D. Diffie-Hellman
C and D
Which of the following are examples of symmetric algorithms? (You can choose more than one.)
A. El Gamal
B. RC4
C. SHA
D. DSA
B
Buddy system for memorizing Asymmetric algorithms.
RSA and DSA
ECC and El Gamal
DH (Diffie Helman) and Knapsack
What type of cryptography does SSL/TLS use for data encryption?
A. Symmetric
B. Asymmetric
C. Neither
D. Diffie-Helman
A
Asymmetric is used to exchange keys. Symmetric is used to encrypt the data.
This algorithm uses factorization with prime numbers, (called the trapdoor function), and is currently the standard for digital signatures. It can also be used for Key distribution and encryption.
A. Diffie-Helman
B. RSA
C. DSA
D. El Gamal
RSA
DSA can only be used for digital signing.
This block cipher mode of operation is FAST but usable only for the encryption of very short messages b/c the encrypting identical plaintext with the same key will produce identical ciphertext.
A. Cipher Block Chaining (CBC) mode
B. Output Feedback (OFB) mode
C. Counter Mode (CTR)
D. Electronic Code Book (ECB) mode
Electronic Code Book (ECB) mode
This block cipher mode of operation does not reveal a pattern because each block of text, the key, and the value based on the previous block are processed in the algorithm and applied to the next block of text, resulting in more random ciphertext. The first block is encrypted with an initialization vector (IV).
A. Cipher Block Chaining (CBC) mode
B. Output Feedback (OFB) mode
C. Counter Mode (CTR)
D. Cipher Feedback (CFB) mode
Cipher Block Chaining (CBC) mode
This block cipher mode of operation emulates a stream cipher which is useful for encrypting small (think 8-bit key commands) over a remote connection to a server.
A. Cipher Block Chaining (CBC) mode
B. Cipher Feedback (CFB) mode
C. Counter Mode (CTR)
D. Electronic Code Book (ECB) mode
Cipher Feedback (CFB) mode
This block cipher mode of operation is like Cipher Feedback mode but ensures possible errors don’t affect encryption and decryption processes. Good for transmission sensitive to errors like digitized video or digitized voice.
A. Counter Mode (CTR)
B. Cipher Feedback (CFB) mode
C. Output Feedback (OFB) mode
D. Cipher Block Chaining (CBC) mode
Output Feedback (OFB) mode
This block cipher mode of operation uses and IV counter tha increments for each plaintext block that needs to be encrypted. There is no chaining involved and is used in encrypting ATM cells for virtual circuits, in IPSec, and in the wireless security standard IEEE 802.11i
A. Counter Mode (CTR)
B. Cipher Feedback (CFB) mode
C. Output Feedback (OFB) mode
D. Cipher Block Chaining (CBC) mode
Counter Mode (CTR)
This symmetric algorithm is uses 48 rounds in its computation, making it resistant to differential cryptanalysis, but it takes a heavy performance hit as a result.
A. Blowfish
B. AES
C. RC6
D. 3DES
3DES
All but one of the following can provide integrity and data origin authentication. Which one can not?
A. Hash
B. HMAC
C. CBC-MAC
D. CMAC
Hash
Which of the following can ensure that a message has not been changed intentionally?
A. One-Way hash
B. HMAC
C. Message Integrity
D. MD4
HMAC
A generic one-way hash protects against UNINTENTIONAL errors that change the message.
