Symmetric Encryption and Publickey Crytography (ch20, 21) Flashcards
Symmetric encryption is also referred to as secret-key or single-key encryption.
True
The ciphertext-only attack is the easiest to defend against.
True
A brute-force approach involves trying every possible key until an intelligible translation of the ciphertext into plaintext is obtained.
True
AES uses a Feistel structure.
False
Each block of 64 plaintext bits is encoded independently using the same key? is a description of the CBC mode of operation.
False
Timing attacks are only applicable to RSA.
False
Using PKCS (public-key cryptography standard), when RSA encrypts the same message twice, different ciphertexts will be produced.
True
The Diffie-Hellman algorithm depends for its effectiveness on the difficulty of computing discrete logarithms.
True
A key exchange protocol is vulnerable to a man-in-the-middle attack if it does not authenticate the participants.
True
Just like RSA can be used for signature as well as encryption, Digital Signature Standard can also be used for encryption.
False
In general, public key based encryption is much slower than symmetric key based encryption.
True
________ is the original message or data that is fed into the encryption process as input.
A. Plaintext
B. Encryption algorithm
C. Decryption algorithm
D. Ciphertext
A
Which of the following would allow an attack that to know the (plaintext of) current message must be the same as one previously transmitted because their ciphtertexts are the same?
A. CBC
B. ECB
C. CFB
D. OFB
B
________ is a term that refers to the means of delivering a key to two parties that wish to exchange data without allowing others to see the key.
A. Session key
B. Subkey
C. Key distribution technique
D. Ciphertext key
C
Which of the following feature can only be provided by public-key cryptography?
A. Confidentiality protection
B. Integrity protection
C. Non-repudiation
D. None of the above
C