Question

I am experimenting with multithreading and password crackers seem like the simplest (easier then opengl) intensive task.

Would it be worth the time to write a multithreaded password cracker? would it boost efficiency on a hyper threaded duel core (4 cores)?

Would it be faster to have 1 thread generate the hash while another compares it or divide the generating amongst multiple threads.

A lot of questions I know, an answer to any of them would be great, thanks.

Answer 1

After extensive research I can say multithreading a password cracker is not the best use of time.

Multithreading, while capable of boosting resource efficiency, is also useful in server\client interactions.

In the example below multithreading is used to allow a server to accept and interact with multiple clients at the same time.

while (1) {

    listen(sd,10);
    cliLen=sizeof(cliAddr);
    printf("[LISTINING %u][%u]\n",SERVER_PORT,i);

    //Accept Connection

    newSd = accept(sd, (struct sockaddr *) &cliAddr, &cliLen);
    if(newSd < 0)
    {
        perror("cannot accept connection");
        exit(3);
    }

    pthread_create(&pth, NULL, &connectionManager, (void*)newSd);

    i++;         
}

….
….

int connectionManager(newSd,data){


send(newSd,"[Connection Created on New Thread]\n\r",strlen("[Connection Created on New Thread]\n\r"), 0);
//pthread_create(&pthsend,NULL, &dataSender, (void*)newSd);
pthread_create(&pthget, NULL, &dataGetter, (void*)newSd);
pthread_join(pthsend, NULL);
pthread_join(pthget, NULL);
close(newSd);
pthread_exit; 


}

Further research can be done to determine an efficiency “sweet spot”. This will likely be different for all Boxes.