| 0,0 → 1,82 |
|---|
| # Encrypted Data |
| data_set = ((3781,14409),(31552,3930),(27214,15442),(5809,30274), |
| (5400,31486),(19936,721),(27765,29284),(29820,7710), |
| (31590,26470),(3781,14409),(15898,30844),(19048,12914), |
| (16160,3129),(301,17252),(24689,7776),(28856,15720), |
| (30555,24611),(20501,2922),(13659,5015),(5740,31233), |
| (1616,14170),(4294,2307),(2320,29174),(3036,20132), |
| (14130,22010),(25910,19663),(19557,10145),(18899,27609), |
| (26004,25056),(5400,31486),(9526,3019),(12962,15189), |
| (29538,5408),(3149,7400),(9396,3058),(27149,20535), |
| (1777,8737),(26117,14251),(7129,18195),(25302,10248), |
| (23258,3468),(26052,20545),(21958,5713),(346,31194), |
| (8836,25898),(8794,17358),(1777,8737),(25038,12483), |
| (10422,5552),(1777,8737),(3780,16360),(11685,133), |
| (25115,10840),(14130,22010),(16081,16414),(28580,20845), |
| (23418,22058),(24139,9580),(173,17075),(2016,18131), |
| (19886,22344),(21600,25505),(27119,19921),(23312,16906), |
| (21563,7891),(28250,21321),(28327,19237),(15313,28649), |
| (24271,8480),(26592,25457),(9660,7939),(10267,20623), |
| (30499,14423),(5839,24179),(12846,6598),(9284,27858), |
| (24875,17641),(1777,8737),(18825,19671),(31306,11929), |
| (3576,4630),(26664,27572),(27011,29164),(22763,8992), |
| (3149,7400),(8951,29435),(2059,3977),(16258,30341), |
| (21541,19004),(5865,29526),(10536,6941),(1777,8737), |
| (17561,11884),(2209,6107),(10422,5552),(19371,21005), |
| (26521,5803),(14884,14280),(4328,8635),(28250,21321), |
| (28327,19237),(15313,28649)) |
| |
| def Extended_Euclidian(a, b): |
| ''' Takes values a and b and returns a tuple (r,s,t) in the following format: |
| r = s * a + t * b where r is the GCD and s and t are the inverses of a and b''' |
| t_ = 0 |
| t = 1 |
| s_ = 1 |
| s = 0 |
| q = a//b |
| r = a - q * b |
| # print("%d\t= %d * %d + %d" % (a, q, b, r)) |
| while r > 0: |
| temp = t_ - q * t |
| t_ = t |
| t = temp |
| temp = s_ - q * s |
| s_ = s |
| s = temp |
| a = b |
| b = r |
| q = a//b |
| r = a - q * b |
| # print("%d\t= %d * %d + %d" % (a, q, b, r)) |
| r = b |
| return (r, s, t) |
| |
| def Inverse(a, b): |
| '''Returns the multiplicative inverse of a mod b''' |
| ret = Extended_Euclidian(a,b) |
| if (ret[1] < 0): |
| inv = ret[1] + b |
| else: |
| inv = ret[1] |
| return inv |
| |
| def Decrypt(n): |
| '''Decodes an encoding where n = a * 26^2 + b * 26 + c''' |
| a = int(n / 676) |
| n = n - (a * 676) |
| b = int(n / 26) |
| n = n - (b * 26) |
| c = n |
| return (a, b, c) |
| |
| if __name__ == '__main__': |
| p = 31847 |
| a = 7899 |
| |
| # For each encrypted data packet, decrypt it using the following function: |
| # d(y_1,y_2) = y_2(y_1^a)^-1 mod p |
| for i in data_set: |
| d = i[1] * Inverse(i[0]**a,p) % p |
| s = Decrypt(d) |
| print("%c%c%c" % (chr(s[0]+65), chr(s[1]+65), chr(s[2]+65)), end='') |
| print() |