Basic cyber security says that passwords should be encrypted and hashed, so that even the company storing them doesn’t know what the password is. (When you log in, the site performs the same encrypting and hashing steps and compares the results) Otherwise if they are hacked, the attackers get access to all the passwords.
I’ve noticed a few companies ask for specific characters of my password to prove who I am (eg enter the 2nd and 9th character)
Is there any secure way that this could be happening? Or are the companies storing my password in plain text?
Theoretically: Shamir’s Secret sharing with a limited amount of secret material available to the helpdesk could form a relatively secure method to validate k knowledge of the password without disclosing all of it.
Practically: pretty sure they just store (part of) your password in plaintext. Getting SSS working can be difficult and it’s much easier to just pretend your password is stored safely instead.
In between those two you have intermediate options (hashing a bunch of combinations of position + salt + character with a very large amount of rounds) but if we’re talking about two characters, you may as well just store the characters in the dagaabse directly
Shamir’s secret sharing, which was new to me, still means the password must be unencrypted though!? Otherwise there’s no secret that can be shared. You can’t get individual characters of non-reversible-hashed passwords.
Reading the Wikipedia page about Shamir’s secret sharing I don’t see anything about sharing part of the secret data, only that the decryption key is split-shared.
With SSS the secrets are calculated either on your end (in the browser) or at the moment you would normally hash the password when you first set it. And yes, the server does receive some secrets as well.
What you basically do is encrypt something with the combined secret key. The helpdesk only has one or a few parts of the secret key themselves. They need one or more secrets from you to derive enough of the secret key to decrypt the message. That message could literally be “congratulations you found the secret key” for all intents and purposes.
If they enter the secrets you provide (say, secrets derived from the second and ninth position, and the appropriate characters in a password) and the message gets decrypted successfully, the other side will know that you are who you claim you are, without ever disclosing all of your secret material. It doesn’t necessarily matter which part of the secret your share, as long as you share enough to successfully decrypt a message, but the agents probably want random positions to make sure someone who overheard you on the phone can’t just reuse the letters you used.
This is quite tricky to set up so I doubt it’s commonly used. It’s also vulnerable to potential brute forcing if the secrets stored by the bank can be extracted, but if the helpdesk doesn’t have direct server access only the IT people inside the bank (who can probably read the password you submit to their servers anyway) can really brute force anything.
So in this case the shared partial secret key would be a part of the secret. That seems like a bad idea, bad practice for security. But I see how it’d work.
It’s not necessarily bad practice, that’s exactly how such a system should work, assuming the keys material is good enough not to be brute forced easily. SSS is better if you combine strong key material (actual cryptographic keys, for example) but reading out ECDSA keys over the phone is quite the hassle.
I’ve never actually encountered a business that asked for my password over the phone and I would feel sketched out regardless of how good their implementation might theoretically be. It’s better than voice identification, but I’d rather keep my passwords to myself.
I’ve noticed a few companies ask for specific characters of my password to prove who I am (eg enter the 2nd and 9th character)
They what?!
This is a huge red flag and should not even be possible for your primary password, if they are following basic security principles. Are you sure this isn’t a secondary PIN or something like that?
NatWest in the Uk does it for both the password and the pin, has been since I signed up like 10 years ago. I assumed they do it so you don’t enter a full password that someone could access later. No idea how they work out but they are big and I assume if it was insecure they’d have had issues by now. I assume they store the letter groupings in advance.
I assume if it was insecure they’d have had issues by now.
At this point, it’s okay to assume that they have had issues and they haven’t disclosed them.
Can a company be sued for storing pw in plaintext?
I’m not sure if they can be sued for that. Surely you can sue them if they get hacked and you’re negatively affected, though.
So i get the feeling that storing pw in plaintext is heavily frowned upon but not illegal
Not ilegal. Just very stupid. Like it’s not illegal to leave your house’s front door unlocked.
I’m assuming they’re plain text. There’s is no perceivable way they can only use those data points to to figure out which hash it is. Unless of course they’re using their own “hashing” function which isn’t secure at all since it’s probably reversible.
Theoretically they could take those two characters + a salt and then also store that hash. So there it is technically a way to do it although it’d be incredibly redundant, just ask for the actual password at that point.
Please don’t do that. Brute force attacks are very easy on single characters, even two of them.
Yes, I did a reply about this above because this idea has been suggested a few times and it’s truly a bad security move. I’d prefer they just encrypted it and made sure the key was stored separate from the database. That’s more secure than this idea.
Perhaps they validate the passwords client side before hashing. The user could bypass the restrictions pretty easily by modifying the JavaScript of the website, but the password would not be transmitted un-hashed.
It is worth pointing out that nearly any password restriction like this can be made ineffective by the user anyway. Most people who are asked to put a special character in the password just add a ! to the end. I think length is still a good validation though and it runs into the same issue @randombullet@lemmy.world is asking about
How would they validate individual characters client side? The set password is on the server.
When you are filling out the web form with your password it’s stored plain text in the web browser and accessible via JavaScript. At that point, a JavaScript function checks the requirements like length and then does the salting/hashing/etc and sends the result to the server.
You could probably come up with a convoluted scheme to check requirements server side, but it would weaken the strength of the hash so I doubt anyone does it this way. The down side of the client side checking is that a tenacious user could bypass the password requirements by modifying the JavaScript. But they could also just choose a dumb password within the requirements so it doesn’t matter much… “h4xor!h4xor!h4xor!” Fits most password requirements I have seen but is probably tried pretty quickly by password crackers.
OP asked about validating specific characters of the password. Commenter then said it has to be stored in plain text for that to work. Then you commented about client-side validation. Which I really don’t see has anything to do with the stuff before in this thread?
Commenter said it has to be plain text server side. You implied validating client side would allow storing hashed passwords and still validating individual characters of the password. Which I asked how that would work. Your answer to that seems to give a general view of password handling on forms and validation?
Do they always ask for the same characters? I’d imagine they could hash the password as well as saving only the 2nd and 9th characters as plaintext. Still a bit of a security risk but not nearly as bad
One of the main differences between hashing and encrypting is that encryption is réversible by some means, while hashing isn’t. The irreversibility is what makes it so ideal for storing a password in a way that definitely can’t be used to get the original password back, even if someone steals the whole database with the passwords in it.
Those companies that ask for specific characters might be encrypting the passwords, but they definitely aren’t hashing them.
Full-stack dev here, not necessarily in answer to OP’s question, but in my experience it is a pretty standard practice that when you log in to a service, the web page sends your unhashed creds to the server, where your password is then hashed and compared to the stored hash. Via HTTPS/TLS/SSL, this is a reasonably secure practice since the creds are still encrypted while in transport. Hashing is a computationally expensive process that (before the advent of WASM) wasn’t really feasible to do on the client side.
What is WASM ?
Web Assembly. Pretty neat tech if you read up on it.
I have never heard of anything secure doing that. Assuming they have taken security steps, it would mean they recorded those characters in plaintext when you set your password, but that means that at least those characters aren’t secure, and a breach means some hacker has a great hint.
When the hashing occurs, it happens using the code you downloaded when you visit the site, so it’s your computer that does the hash, and then just the hash is sent onwards, so they can’t just pull the letters out of a properly secure password.
A secure company would use two-factor authentication to verify you above and beyond your password, anyway, since a compromised password somewhere else automatically compromises questions about your password.
A lot of banks in the UK do it. They normally have a secondary pin that they will ask for 2 or 3 characters of.
This means that if you log in and get keylogged/shoulder surfed etc they don’t get the full pin. The next time you login you will get asked for different characters.
Not great, but not awful either - going away now that 2fa is more common
