Exam 2: Cryptographic Tools

If the only form of attack that could be made on an encryption algorithm is brute-force,then the way to counter such attacks would be to __________ .

A __________ is created by using a secure hash function to generate a hash value for a message and then encrypting the hash code with a private key.

A message authentication code is a small block of data generated by a secret key and appended to a message.

Cryptanalytic attacks try every possible key on a piece of ciphertext until an intelligible translation into plaintext is obtained.

Digital signatures and key management are the two most important applications of __________ encryption.

Public-key algorithms are based on simple operations on bit patterns.

The two criteria used to validate that a sequence of numbers is random are independence and _________ .

Two of the most important applications of public-key encryption are digital signatures and key management.

The __________ is the encryption algorithm run in reverse.

The simplest approach to multiple block encryption is known as __________ mode,in which plaintext is handled b bits at a time and each block of plaintext is encrypted using the same key.

In July 1998 the __________ announced that it had broken a DES encryption using a special purpose "DES cracker" machine.

The __________ algorithm takes the ciphertext and the secret key and produces the original plaintext.

T F 4.The secret key is input to the encryption algorithm.

A __________ processes the input elements continuously,producing output one element at a time.

__________ is the scrambled message produced as output.

__________ is provided by means of a co-processor board embedded in the tape drive and tape library hardware.

The advantage of a stream cipher is that you can reuse keys.

A __________ attack exploits the characteristics of the algorithm to attempt to deduce a specific plaintext or to deduce the key being used.

Modes of operation are the alternative techniques that have been developed to increase the security of symmetric block encryption for large sequences of data.

The strength of a hash function against brute-force attacks depends solely on the length of the hash code produced by the algorithm.