password-protection

I've been reading up on the benefits of salting and hashing passwords, but one thing still eludes me... When I provide a random salt for each user, how do I then know what the salt was when I try to authenticate them to login? so if I do.. HASHPW = PW.RANDOMNUMBER I could store the random number in the database, but that seems to kill the entire point of adding the salt.. doesn't it? I could also use a non random number for each salt, but then that also kills the point of the salt because if they figure it out they have all my users passwords... I just started learning PHP and MySQL and

I've been asked to implement some changes/updates to an intranet-site; make it 'future proof' as they call it. We found that the passwords are hashed using the MD5 algorithm. (the system has been around since 2001 so it was adequate at time). We would now like to upgrade the hashing-algorithm to a stronger one (BCrypt-hash or SHA-256). We obviously do not know the plaintext-passwords and creating a new password for the userbase is not an option *) . So, my question is: What is the accepted way to change hashing-algorithm without having access to the plaintext passwords? The best solution would

Possible Duplicate: Storing a password I am using shared preference to store password. Is it is secure to save the password data as it is, or i have to encrypt it before saving it. Please help me with sample code. Thanks in Advance, You should never save a password directly, instead save a hash of the password. Short answer: it's pretty secure. Long answer: first off, if you are creating an application that allows a user to log into a web / remote service, you might want to look into the AccountManager . It's a bit harder to learn the APIs and intergrate with it, but you get some nice benefits

I'm starting a new app, and I'd like to know how to require a password to open it. I was considering a UIActionSheet in the application didFinishLaunchingWithOptions method of the app delegate implementation file, but am unsure how to go about doing so. I'm going to keep trying though. Found this video , which seems pretty helpeful. Now I've got my UIActionSheet to pop up displaying "Enter password," and am trying to figure how to add a keypad to the action sheet. pendor I think you may have better luck using a full UIViewController instance instead of a UIActionSheet . Adding keyboard

I would like to create a site-wide hash to be used as salt in creating password retrieval tokens. I have been bouncing around stackoverflow trying to get a sense of the best way to do this. Here's the reset process: When a user requests a password reset email the code generates a retrieval token: $token = hash_hmac('sha256', $reset_hash* , $site_hash) *$reset_hash is a hash created using phpass HashPassword() function, saved in the user table. I then send the token in a URL to the users email address. They click before the token times out in an hour. I match their submission with the a