Quiz 7: Symmetric Encryption and Public-Key Cryptography

The principal attraction of ________ compared to RSA is that it appears to offer equal security for a far smaller bit size, thereby reducing processing overhead.

A.ECC

________ attacks have several approaches, all equivalent in effort to factoring the product of two primes.

A.Mathematical

________ is the original message or data that is fed into the encryption process as input.

A.Plaintext

Cryptographic systems are generically classified by _______.

A.the type of operations used for transforming plaintext to ciphertext B.the number of keys used C.the way in which the plaintext is processed

_________ was the first published public-key algorithm.

B.Diffie-Hellman

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?

B.ECB

________ 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.

C.Key distribution technique

Which of the following feature can only be provided by public-key cryptography?

C.Non-repudiation

________ are analogous to a burglar guessing a safe combination by observing how long it takes to turn the dial from number to number.

D.Timing attacks

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

Just like RSA can be used for signature as well as encryption, Digital Signature Standard can also be used for encryption.

False

Timing attacks are only applicable to RSA.

False

A brute-force approach involves trying every possible key until an intelligible translation of the ciphertext into plaintext is obtained.

True

A key exchange protocol is vulnerable to a man-in-the-middle attack if it does not authenticate the participants.

True

In general, public key based encryption is much slower than symmetric key based encryption.

True

Symmetric encryption is also referred to as secret-key or single-key encryption.

True

The Diffie-Hellman algorithm depends for its effectiveness on the difficulty of computing discrete logarithms.

True

The ciphertext-only attack is the easiest to defend against.

True

Using PKCS (public-key cryptography standard), when RSA encrypts the same message twice, different ciphertexts will be produced.

True