Which wireless standard uses the 2.4 GHz frequency band only? 802.11a
802.11b
802.11n
802.11ac
lmk!

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.

3. bob is arguing that if you use output feedback (ofb) mode twice in a row to encrypt a long message, m, using the same key each time, it will be more secure. explain why bob is wrong, no matter what encryption algorithm he is using for block encryption (15 points).

Design a pos circuit that displays the letters a through j on a seven-segment indicator. the circuit has four inputs w, x, y, and z which represent the last 4 bits of the uppercase ascii code for the letter to be displayed. thus, if wxyz = 0001 then "a" will be displayed. (any answer with 22 or fewer gates and inverters, not counting any for the inputs, is acceptable)