8. (20 pts)
a. RSA encryption. Let n = pq = (7)(17) = 119 and e = 5 define a(very modest) RSA public key encryption. Since 25 < 119 <2525, we can only encode one letter (two digit representation) at atime. Use the function ? = ? mod ? to encode the word MATHY into aseries of five numbers that are less than n.
b. To decrypt an RSA encrypted message, we need to find d, themultiplicative inverse of e modulo (p-1)(q-1). Use Euclidianalgorithm and two-pass method to determine the Bezout coefficientof e for the RSA in Part a. above. Then write down the decryptionfunction.
A 0 B 1 C 2 D 3 E 4 F 5 G 6 H 7 I 8 J 9 K 10 L 11 M 12 N 13 O 14P 15 Q 16 R 17 S 18 T 19 U 20 V 21 W 22 X 23 Y 24 Z 25
