Assignment 8

Due on 25/04/2023

Problem(s)

Part 1

1. Write a function extendedGCD(a, b) to find GCD (Greatest Common Divisor) of a, and b using the Extended Euclidian Algorithm

   • The function must return three values, i.e., GCD, x, and y
   • Run your code to find the GCD for the following three sets of (a, b):
     • (91,11)
     • (391,299)
     • (4324525,96)
     • (25252525,10101000)
     • (23964896,743288)

Part 2

1. Write a function getNkeys(seed, N) that takes 2 values as input and generates N different binary strings of 48-bits. The function should follow the constraints given below:

   • seed should be a 64-bit binary string and keep N = 3
   • Initially, the seed MUST be converted to a 56-bit binary string K0, using compressM2N() done in Lab 7 and find (X0, Y0)
   • To generate key-i (Ki) of N, use shiftNmerge(data,N), and PC_M2N(data, M, N) to find subsequent (Xi, Yi) and Ki (Lab 8)
   • i represents the sequence number of key, that must depend upon the previous X and Y
   • Use the same PC table for every round as used during Lab 8

---

Back to Homepage