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?
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.
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.
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
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.
This seems somehow worse than simply requiring the same few characters each time, since they would either have to store the complete passwords in plaintext, or compute and store the hash for every permutation of 2-3 characters, which is wildly inefficient. You’d also be susceptible to leaking your password if for some reason you are under long term surveillance, since at some point you would presumably have provided all of the characters making up the password.
It’s normally an additional password/code, so it’s probably stored in plaintext.
The random character selection is what makes it useful. Stops someone who just captured your details from logging straight in (probably).
2FA is superior in every way to it. Most have now switched to sending you a chip & pin card reader to generate OTPs.
Unless they hash and store various combinations of characters in addition to, or instead of, the whole password. I haven’t heard of anyone doing this. If you were to pad them with a unique salt and a pepper before hashing each combination, you could end up with something more secure than just hashing the whole password Edit: I was wrong it seems; you’d still end up with something insecure. But hashing the whole password, if done properly, is already secure enough so this would seem like needless complication unless there’s some unusual concern about the password being intercepted in transit, and in that case you’d have other problems anyway.
I have heard of this thing of asking for selected characters of a static second authentication factor (e.g. a PIN), but not of a password itself. And now that we have proper 2FA systems I haven’t seen anything like that in a while.
It’ll be less secure.
If they hash a subset, then those extra characters are literally irrelevant, since the hash algorithm will exclude them. Like if they just hashed the first 5 characters, then “passw” is the same as “password” and all those permutations. Hashing is safe because it’s one-way, but simple testing on the hashing algorithm would reveal certain characters don’t matter.
Protecting a smaller subset of characters in addition to the whole password is slightly better but still awful. Cracking the smaller subset will be significantly easier using rainbow tables, and literally gives a hint for the whole password, making a rainbow table attack significantly more efficient. Protecting the whole thing (with no easy hints) is way more secure.
It also adds nothing to keylogging, since it’s not even a new code, it’s part of the password.
There was a time where that level of security was acceptable, and it still could be ok on a closed system like an ATM, as the other reply to my comment pointed out, but this kind of protection on a standard computer is outdated and adds holes.
Less secure if you come at it from the perspective of cracking the password, but probably more secure in real-world terms.
If you type in your bank password and somebody’s compromised your browser, they now have your entire password.
If you type in the third, fourth and eighth digits and somebody’s compromised your browser, they still can’t access your account.
Obviously full 2FA is probably better, but
- A bank requiring a smartphone to bank with them is probably a no-go
- A bank probably has to deal with some of the least technical users that are out there
If it’s too hard for certain users to engage with the system correctly, they’ll try to sneak around it in ways that could compromise their security more than if the bank had just gone with the specific digits thing in the first place.
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.
I would assume they have the whole password in plain text, then. Not much you can do about it, just make sure you’re not re-using any part of that password for other services. And if you are, then you should start changing them all to something unique, ideally with a password manager like Keepass or BitWarden. This is a good habit anyway, because you can never really know how companies are handling their IT security.
Crazy that that hasn’t become an issue for them yet! Thanks for the tips! I used to be pretty bad with my passwords but I’m reformed and using KeePass for everything these days.
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
Theoretically they could hash the the two characters with a salt and store it that way, but extremely unlikely they’d actually do that. And also fairly pointless. But still technically possible.
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.
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.
