Compared to the lines of the Computer Shopper program, how would this variant
evaluate out time-complexity wise? I'm not sure how sophisticated the
attacks on pseudo-random generators are.
This one includes an random generator shift, based upon the random numbers.
-----------------------------------------------------------------------------
#include
static int seed;
int rand1(int seedval) { return (seed * 183041 % 183319 + 1); }
int rand2(int seed) { return (seed * 502001 % 502441 + 1); }
void main(int argc, char *argv[]) {
int current;
FILE *input, *output;
if (argc !=3) {
fprintf(stderr, "Usage: %s input output\n", argv[0]);
exit(1);
}
if ((input = fopen(argv[1], "rb")) == NULL) {
fprintf(stderr, "Error opening inputfile %s\n",argv[1]);
}
if ((output = fopen(argv[2], "wb")) == NULL) {
fprintf(stderr, "Error opening outputfile %s\n",argv[1]);
}
printf("Enter cipher key: ");
seed = getc(stdin);
current = fgetc(input);
while(!feof(input)) {
fputc(current ^ seed, output);
current = fgetc(input);
if (seed && 8) {
seed = rand1(seed);
}
else {
seed = rand2(seed);
}
}
fclose(input);
fclose(output);
}
--
Tyler Yip, UnixWeenie(tm) \ God put me on Earth to accomplish a certain
email: davros@ecst.csuchico.edu \ number of things. Right now I am so far
California State University, Chico \ behind I will never die. -Calvin & Hobbes
