Program to implement RSA(Ron Rivest, Adi Shamir and Len Adleman, who invented it in 1977 [RIVE78]).
#include<stdio.h> #include<conio.h> #include<ctype.h> #include<math.h> #include<string.h> void main() { int a, b, i, j, t, x, n, k = 0, flag = 0, prime[100]; char m[20], pp[20]; float p[20], c[20]; double e, d; clrscr(); for(i = 0; i < 50; i++) { flag = 0; for(j = 2; j < i / 2; j++) if(i % j == 0) { flag = 1; break; } if(flag == 0) prime[k++] = i; } a = prime[k - 1]; b = prime[k - 2]; n = a * b; t = (a - 1) * (b - 1); e=(double)prime[2]; d=1 / (float)e; printf("\nKey of encryption is:%lf", d); printf("\nEnter the text:"); scanf("%s", &m); x = strlen(m); printf("\nSource------------destination"); printf("\nChar\tnumeric\tcipher\t\tnumeric\t\tchar\n"); for(i = 0; i < x; i++) { printf("%c", m[i]); printf("\t%d", m[i] - 97); c[i] = pow(m[i] - 97, (float)e); c[i] = fmod(c[i], (float)n); printf("\t%f", c[i]); p[i] = pow(c[i], (float)d); p[i] = fmod(p[i], (float)n); printf("\t%f", p[i]); pp[i] = p[i] + 97; printf("\t%c\n", pp[i]); } getch(); }
Output:
Key of encryption is:0.500000 Enter the text:geethanjali Source------------destination Char numeric cipher numeric char g 6 36.000000 6.000000 g e 4 16.000000 4.000000 e e 4 16.000000 4.000000 e t 19 361.000000 19.000000 t h 7 49.000000 7.000000 h a 0 0.000000 0.000000 a n 13 169.000000 13.000000 n j 9 81.000000 9.000000 j a 0 0.000000 0.000000 a l 11 121.000000 11.000000 l i 8 64.000000 8.000000 i
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UpdatedNov 05, 2014
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Views2,195