Suppose N people want to communicate with each of N – 1 other people using symmetric key encryption. All communication between any two peo- ple, i and j, is visible to all other people in this group of N, and no other per- son in this group should be able to decode their communication. How many keys are required in the system as a whole? Now suppose that public key encryption is used. How many keys are required in this case?

Jenna updated her status on a social network regarding her upcoming vacation. what information should jenna not provide when updating her status on a social networking site? a. her favorite quote b. her likes in popular culture c. her routine d. her opinions on social issues res

Which of the following statements correctly identifies a problem with sanitization methods? a. methods are not available to remove data ensuring that unauthorized personnel cannot retrieve data. b. even fully incinerated media can offer extractable data. c. personnel can perform sanitization steps improperly. d. stored data is physically etched into the media.

Write a program called assignment3 (saved in a file assignment3.java) that computes the greatest common divisor of two given integers. one of the oldest numerical algorithms was described by the greek mathematician, euclid, in 300 b. c. it is a simple but very e↵ective algorithm that computes the greatest common divisor of two given integers. for instance, given integers 24 and 18, the greatest common divisor is 6, because 6 is the largest integer that divides evenly into both 24 and 18. we will denote the greatest common divisor of x and y as gcd(x, y). the algorithm is based on the clever idea that the gcd(x, y) = gcd(x ! y, y) if x > = y and gcd(x, y) = gcd(x, y ! x) if x < y. the algorithm consists of a series of steps (loop iterations) where the “larger” integer is replaced by the di↵erence of the larger and smaller integer. this continues until the two values are equal. that is then the gcd.