NO.42 Changes to one character in the plain text affect multiple characters in the cipher text, unlike in historical algorithms where each plain text character only affect one cipher text character.

NO.43 What is the formula m^e %n related to?

NO.44 When learning algorithms, such as RSA, it is important to understand the mathematics being used. In RSA, the number of positive integers less than or equal to some number is critical in key generation. The number of positive integers less than or equal to n that are coprime to n is called ______.

NO.45 Which service in a PKI will vouch for the identity of an individual or company?

NO.46 John works as a cryptography consultant. He finds that people often misunderstand the reality of breaking a cipher. What is the definition of breaking a cipher?

NO.47 Cylinder tool. Wrap leather around to decode. The diameter is the key. Used in 7th century BC by greek poet Archilochus.

NO.48 John is trying to explain the basics of cryptography to a group of young, novice, security students. Which one of the following most accurately defines encryption?

NO.49 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?

NO.50 A number that is used only one time, then discarded is called what?

NO.51 Represents the total number of possible values of keys in a cryptographic algorithm or other security measure, such as a password.

NO.52 A technique used to increase the security of block ciphers. It consists of steps that combine the data with portions of the key (most commonly using a simple XOR) before the first round and after the last round of encryption.

NO.53 What is the name of the attack where the attacker obtains the ciphertexts corresponding to a set of plaintexts of his own choosing?

NO.54 The greatest weakness with symmetric algorithms is _____.

NO.55 Which of the following techniques is used (other than brute force) to attempt to derive a key?

NO.56 This hash function uses 512-bit blocks and implements preset constants that change after each repetition. Each block is hashed into a 256-bit block through four branches that divides each 512 block into sixteen 32-bit words that are further encrypted and rearranged.

NO.57 During the process of encryption and decryption, what keys are shared?