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Bruce Schneier is a well-known and highly respected cryptographer. He has developed several pseudo random number
generators as well as worked on teams developing symmetric ciphers. Which one of the following is a symmetric block
cipher designed in 1993 by Bruce Schneier team that is unpatented?
Correct Answer: B
Blowfish
https://en.wikipedia.org/wiki/Blowfish_(cipher)
Blowfish is a symmetric-key block cipher, designed in 1993 by Bruce Schneier and included in many cipher suites and encryption products.
Which of the following are valid key sizes for AES (choose three)?
Correct Answer: A, C, D
Correct answers: 128, 192, 256
https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
The Advanced Encryption Standard (AES), also known by its original name Rijndael, is a specification for the encryption of electronic data established by the U.S. National Institute of Standards and Technology (NIST) in 2001.
AES is a subset of the Rijndael block cipher developed by two Belgian cryptographers, Vincent Rijmen and Joan Daemen, who submitted a proposal to NIST during the AES selection process. Rijndael is a family of ciphers with different key and block sizes. For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits.
As a network administrator, you have implemented WPA2 encryption in your corporate wireless network
. The WPA2 ' s ________ integrity check mechanism provides security against a replay attack.
Correct Answer: A
CBC-MAC
https://en.wikipedia.org/wiki/CBC-MAC
A cipher block chaining message authentication code (CBC-MAC) is a technique for constructing a message authentication code from a block cipher. The message is encrypted with some block cipher algorithm in CBC mode to create a chain of blocks such that each block depends on the proper encryption of the previous block. This interdependence ensures that a change to any of the plaintext bits will cause the final encrypted block to change in a way that cannot be predicted or counteracted without knowing the key to the block cipher. Using in WPA2 for integrity check and provides security against a replay attack.
Which one of the following are characteristics of a hash function? (Choose two)
Correct Answer: B, C
Correct answers: One-way, Fixed length output
https://en.wikipedia.org/wiki/Cryptographic_hash_function
A cryptographic hash function is a mathematical algorithm that maps data of arbitrary size (often called the " message " ) to a bit array of a fixed size (the " hash value " , " hash " , or " message digest " ). It is a one-way function, that is, a function which is practically infeasible to invert.
Original, unencrypted information is referred to as ____.
Correct Answer: B
plaintext
https://en.wikipedia.org/wiki/Plaintext
In cryptography, plaintext usually means unencrypted information pending input into cryptographic algorithms, usually encryption algorithms. Cleartext usually refers to data that is transmitted or stored unencrypted ( " in clear " ).