C program for any encryption/decryption algorithm of your choice?

Write an interactive C program for any encryption/decryption algorithm in operating system

C program for any encryption/decryption algorithm of your choice?
main ()


{


static char k="n0body";


char b [1024]; char *c,*d,*i;


while(c=gets(b))


for(d=c,k;*d;


*d++^=*i++,i=i?i:k);


printf("%s\n", b)


}