Slashdot Mirror
One-Time Pads To Protect Electronic Bank Access
dummkopf writes "CNN reports how Scandinavian banks issue one-time passwords to protect customers' accounts when these use the same password for other, i.e., more insecure email accounts. Having a bank account in the U.S. (with a trusted and well known Bank OF nAtional reach) I always wondered why the security was soooo poor: while it has changed slightly now (better usernames/passwords) it used to be the case that your username was your SSN and your password a number code (!). I am sure most of you will agree with me that this is scary... I live now in Switzerland where one-time passwords for online banking are a must and where my current bank is one of the 'crappy' ones with a little card with one-time passwords like mentioned in the CNN Story. The nicer ones even give you credit-card-size RSA password generator which is combined with a calculator you can keep in your pocket. Hence my question: are others also worried about poor security of online banking in the U.S.? Are there banks which are better than the ones mentioned above?"
Banks in Germany always required you to have:
Login & Password.
And then for EACH transaction an TAN (TransActionNumber) which was a one time password that they mailed to you in a batch of I think 25.
So in order to complete a transaction you not only needed the username and Password but also a TAN.
More secure than they do it here, where you just log in and then it's a free for all.
If you want to e-mail me, use my PGP Key.
Single-use passwords are not the same thing as a one-time pad, which is a form of encryption. However, one-time passwords do sound like a good idea. Given reasonably good encryption like in SSL, then password management becomes a weak point - which this scheme addresses. (Just parroting Schneier, and wondering if this scheme will get mention in the next Crypto-gram newsletter.)
I do my banking with a local bank here in Saudi Arabia which has recently upgraded all its ATM machines with biometrics. I need only to register my fingerprint with the bank and then swipe it at the ATM to do my banking. Years ahead of its time.
I always save my last mod point to mod up a good troll. You people are too serious.
The article in question is describing a one-time password, but not a one-time pad. A one-time pad must be as long as the message being encrypted.
One caveat I had about this article was this....
"Outfitting 1 million customers with such devices could cost $20 million, while Internet fraud for those customers amounts to "tens of thousands at most," said Tony Chew, director of technology risk supervision at the Monetary Authority of Singapore. Singapore banks thus limit dynamic passwords to fund transfers, he said."
This is a pretty bold statement coming from the director of technology risk at eBay. eBay has pretty much become the breeding ground for scams and frauds. With millions of items up for auction at any one time this doesn't make any sense. I believe I read an article several months back that eBay estimated that at any one time about 3% of their auctions are fradulent. A small number in comparison to the number of auctions that are ongoing. Doing a totally unscientific experiment, I averaged about 3,000,000 ongoing auctions at eBay, and took the 3% of fraud auctions = 90,000 auctions. I would imagine atleast an average of $100 per auction completion. That puts it at $9,000,000 at any one time and that's only from eBay. This also doesn't acocunt for auctions that were performed outside of eBay as the P-P-P-powerbook one was so performed. Also, imagine the thousands of other financial banks and credit card companies doing business online. And let's not even get started on Paypal.
*Notice.. this was a totally unscientific experient performed by myself.
I think that when putting these numbers all together would make a strong case for such two-factor authentication. I don't mind a second step if it's going to save me money if someone really wants into my banks, eBay acocunts, etc...
Hmmm.
I know it's cliche, but I still get stuck in line behind people who don't understand the basics of the ATM machine interface. Inserting (or swiping) the card throws them off. Grocery store POS systems, never consistent between chains, present even more hurdles. I've seen "Pay at the Pump" customers drive off because they just don't understand the instructions.
You want to give these folks RSA dongles? They don't even see the security implications of putting their entire credit line on their keychain with not even a PIN for validation.
The two problems are simple: People here won't understand it, and they won't care.
Why this works in Europe is beyond me, but I'm sure there are plenty of cliche anti-American rants to help explain it.
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
There really isn't a lot of damage that someone could do with my online banking account.
I can't transfer funds to an account that is not mine.
The information that is available online about me and my account is less than what is available on a check. I guess I should be more concerned about that, but I have no control of my checks once I have used them to pay for something.
My Debit card information is not available online.
About the best someone can do with my account is see my balance.
A scratch-off password list is a password scheme.
a One-time pad is an encryption algorithm.
The two have basically nothing to do with each other.
A one time pad:
Generate a random pattern of bits of the same length as the plaintext. XOR the two. The resulting ciphertext and the random field are now both requried to re-generate the plaintext (to call one the ciphertext and one the key is wrong too. they are both statistically equivalent).
Both are also completely useless by themselves, and truly totally, provably, unbreakable.
This is the only form of unbreakable encryption.
The moment you use a pad more than once, though, it ceases to be a one-time pad, and is breakable.
A few months ago, most (AFAIK, all) portuguese banks updated their online banking auth systems.
... and so on.
There's no standard, and they seem to be having some dificulty balancing user-friendliness with security.
The current "hip" thing is to require a login/password pair, followed by things like:
- Enter the the sixth and second numbers of your ID card/passport (random positions)
- Enter your numeric PIN using the randomly placed JavaScript keypad
- Use the code-matrix card (provided by the bank) and enter the value in square 4C
- Confirm every money-moving operation with digits in random positions from a fixed (long) code given to you by the bank. Said code is regenerated every month.
I don't thinks there's any bank here using plain login/password auth. There were attempts to use personal x509 certs, but most users had trouble installing them or using them.
When the costs of fraudulent use of accounts exceeds the cost of implementing more secure access methods, the banks will then implement more secure methods.
Besides, what can you do from most US online bank systems? Check balances, transfer funds from one type of account to anther (savings to checking), or maybe even transfer to another member of the same bank? These are all very traceable and means that really stupid criminals will get caught.
It's probably much easier to just steal credit card numbers.
...why are we still using a system that relies on you trusting every single person you give your credit card details to? It would be perfectly possible to generate a one-time authorisation code for each transaction...
A "one-time password" means a password that is used once and discarded. This password is typically used only for authentication purposes. By contrast, a "one-time pad" is used for encryption purposes.
One-time pads are almost never useful for typical internet situations because they are very easy to misuse and very insecure when misused. They also don't solve any problem worth solving -- conventional encryption is already strong enough that the added security of a one-time pad has no value in typical internet situations.
One-time passwords, on the other hand, do potentially have some value, because the currently available password authentication systems are quite weak compared to the strength of the corresponding encryption systems.
I've always wondered what keeps someone from simply taking a check you've written (to them possibly) and then using the account information at the bottom with your personal information at the top to drain your account.
Stronger security should only be provided if the cost of implementing that security (money, time, convenience) is less than the costs of not implementing it.
From my perspective, if someone breaks into my account, it's a hassle, but not a huge deal: My account is insured, and I get my money back. I'd rather deal with the inconvenince of this happening once or twice in my lifetime than having to deal with carrying and using a password generator for my entire life.
From the bank's perspective, it is probably cheaper to lose some money to accounts being compramised than to implement better security across the board. That translates to lower costs (or better interest) for me the customer, which is also nice. I'm fairly confident this is true, because were it better (cheaper, more convenient) to have stronger security, my commercial bank (always wanting to make a buck) would be doing that instead.
Your house would be more secure if you had bullet-resistent windows, steel-reinforced cross-bar doors, one-time pad electronic access, and 24/7 security guards, but most people the find much "weaker" deadbolt/key combination to be the BETTER solution.
paintball
If people wanted to pay the additional costs for more secure banking, people would pay them.
The fact that nobody is paying for more security in the free market is a pretty good indication that people don't really want it in the first place.
paintball
Not anymore.
AMEX dropped this service last month.
Dave Barnes 9 breweries within walking distance of my house
For example, I dredge up the number 42 (the answer to Life, the Universe and Everything) and some nonsense word. Let's say it's "snert". Pump it through the construction process and I come up with "first47snertt". Not exactly intuitive, but I'm just adding the number of letters in "first" (5) to my number and the last letter ("t") to the end of the nonsense word.
The result is a pretty strong password. No cracking program is going to have the word in it's dictionary and knowing my password to First National isn't going to tell you that my password to Discover is "discover50snertr". Since "snert" is nonsense anyway, there's no way to tell where the letters come from; you could be sticking the third letter in "Discover" onto the beginning and your nonsense word could be "nertr". There are no rules to how to construct the password, but you want to have an obscure way for the base password to modify the gibberish in the rest so knowing one password will not give you the rest. It saves me the trouble of remembering a lot of strong passwords. Of course, if someone got ahold of several of my passwords and spent enough time on them, they could probably figure out the routine, but that's not as dangerous as using the same password.
And yes, that's just an example. It's not the process I use to construct my own passwords. Trust me, you don't want to know.
===== Murphy's Law is recursive. =====
Your login/password is sent to an "https" address. It is being sent encrypted. Look at the source and see for yourself.
You can't really go by what you see in the URL because that is the address you're looking at, not the address that the form data is posted to.
Most browsers will warn you when you try to send something that's not secure. Most likely you've disabled that warning, as almost everyone does. If you turn it back on, you will notice that the browser won't warn you when you try to login because it is encrypted.
I hate to be a pain in the ass about semantics, but the article headline is a bit misleading. It states One-Time Pads To Protect Electronic Bank Access. The article is about one-time passwords. I'm no crypto expert, but I've done my fair share of reading. A one-time pad is the closest thing available to perfect, unbreakable encryption. The idea is that two pads are generated of completely randomly generated characters, one is used to encrypt the characters (via modulo divide/add/xor, whatever) and immediately destroyed. The other is used to decrypt the message. As long as the pads contain truly random numbers, and they are never reused or recovered, the encryption will never be broken (because the cyphertext is a completely random string of characters).
A one-time password, while usually a pretty good key, is just not the same -- especially if we're talking a 64-bit key with a known encryption scheme. It can be very good, but never even close to the former.
Anyway, like I said earlier I'm not a cryptographer, but a enthusiast (at one time)...but I found that the header in the article was misleading.
-Turkey
I finally got them to use a phrase using l33tspeek for a password: (IE l33tm0m)
Still not as good as your technique, but easy enough for them to remember and not as bad as what they were using.
Mom: (entering password) click, click
Me: "That's an awfully short password mom, what're you using?"
Mom: "My birthdate: 1217"
Me: "AAAUUUGGGHHH!"
Mom: "What's wrong with that? I don't give it out."
(Note: Birthdate changed to protect the innocent.)
Funny as it sounds, just wait till someone get a hold of your identity, you'll be poor and deeply in debt. Scammers are very good and obtaining credit, it helps that they don't fear the repercussions of being unable to pay.
Being poor is no reason to not protect your identity. You'll just get more funny looks.
You are in a maze of twisted little posts, all alike.
Yep, I'm a programmer for one of them.
First of all, your login to our on-line banking system is a randomly generated unique 8 digit number. It's on your ATM card and it's your user ID number for the bank. You also have to remember your 6 digit PIN. But what if you forget your PIN? Well we can't give it to you. Why, because we use one half of a public private key encryption to save only the encrypted version of your PIN. And just to be safe we throw away the private key so even WE can't see what your PIN is. If we ever get hacked (and people try but they've never gotten through. And yes, we've caught them and put them in jail) in any case, if we ever do get hacked they can only see the encrypted version of your PIN and the private key to decrypt them is nowhere to be found.
So you forget your PIN. How do you get a new one? You call us and verify who you are via at least 2 or 3 different ways (I won't tell you how). Then we mail you (yes, snail mail) a new temp PIN to the address your checking account goes to. You can log in ONCE with that temp pin and you are required to change your password after the first login. By the way, if you log in 3 times incorrectly then we lock your account and notify people in the bank that this may be a hack attempt. Good thing we also log the IP address each of those login attempts were coming from.
By the way, when you first signed up you gave us a secret question like "When dad bought that farm in Kentucky he also bought some cattle. What was the name of the first cow that he bought?" You wrote the question yourself which makes it even harder for a hacker to guess what that question is. And when you applied for on-line access you gave us the answer "Matilda". That answer is also encrypted with a one way public-but-no-private-key on our servers. So when you log in with your temp password we're going to ask you the question that only you know the answer to.
I havn't even gotten to physical security. Believe me, don't even try to physically get to our servers, or even to the printers that print your statements. That is, if you could even find the buildings (There are no signs on teh building that say who we are) Add to that triple redundent servers and databases that are located in physically different locations over 200 miles apart so even a terrorist attack on one city won't destroy your bank records. AND those records are backed up and stored in yet another physical location.
And I could talk about all the auditing that the SEC does on us to make sure that our systems are secure, our data is redundently backed up, failover systems work and so on.
So yes, most banks have far more security than you can imagine. You may feel safe again.
Two areas where the USA is just out in left field, cellular services and banking. The first one has stopped suprising me, the second one blew me away. I consider my country (Poland) to be backwards, especially when it comes to commercial services - like banking. It's not.
Not only does my bank use one time passwords, the card they're on is a scratch-off card. This gives me 2 additional levels of protection. Not only does it prevent someone from peeking at my card, but it let's me verify that I made each transaction. I don't need to keep track of the last number I used, it keeps track for me. And I don't need the card unless I'm actually moving money around - all I need is my login and password.
The web interface on my bank is incredible - I can check on all transactions since I opened the account.I can set up sub-accts on the fly, issue debit cards to each of them, and my debit card works great online - so I can keep track of those internet purchases. Between-bank money transfers take a max of 1 day, usually same-day if I make it before 17.30, transfers within my bank are instantaneous - really handy for lending my brother some money *fast*.
And the icing on the cake, the thing that made me go to this bank - instant text-message updates on my current account. I get a transfer - I get an SMS, I buy something - I get an SMS. It's incredibly fast (I usually get the SMS before they hand me the reciept to sign) and incredibly useful. I know how much money I have, how much money I spent that day. It really helps to stem the spending sprees that plastic seems to lend itself to.
And all this, from my local, Polish bank.
It's just a US thing. Banks in the USA are for some reason stuck in the 80's.
All the banks I use in Poland provide one-time passwords for anything important. There are no checks in use, but you can use electronic money transfers to pay for just about anything (this is being introduced as "BillPay" in the US and advertised as big news).
I guess the US was first to develop a mature banking industry with credit cards and checks. This has worked so well (back in the 70's) that banks were not under pressure to innovate.
As I understand it, most of these 'phishing' type things rely on getting someone to log into a web site which looks like their online banking system but isn't. I'd immagine they often get around the SSL problems by just not using SSL - most people won't read the url or notice the little padlock icon or whatever not being there.
Say someone has created such a site - what prevents them from harvesting one time passwords or even challenge/response data this way and using them for fraud immediately? Say the user tries to perform a transfer on the fake interface, provides their transaction number or challenge/response token - the fraudster just uses these details straight away on the real site. The keys they've stolen are fully valid as far as I can see - even the timed challenge/response, if they use it quickly enough. The user would eventually notice that their transaction never happened, but by then they've been robbed. Am I missing something?
If you're poor, how do you pay the debt?
Answer: You don't. You tell the idiots who accepted somebody else as you that they're shit out of luck getting any money out of you and they'd better start looking for the guy who took them to the cleaners.
Which they should have done in the first place.
Of course, it's a hassle TELLING all these people that...
Richard Steven Hack - This sig is TOO GODDAMN SHORT TO DO ANYTHING USEFUL WITH! MORONS!
A one-time-pad is in no way the same as a one-time-password. The only thing common between the two is that they're both used only once.
A one-time-pad is a random string as long as the message you want to send, shared between sender and recipient. The sender encrypts the message by xoring with the one-time-pad and the recipient decrypts by doing xoring the ciphertext with his copy of the one-time-pad. The pads must then never be used again, and must be securely destructed to prevent people who have a copy of the ciphertext from getting hold of them. Unconditionally secure, but often impractical due to the key-handling issues.
A one-time-password, like those Banks here in Europe typically either issue to you on a sheet of 50, or in the form of a calculator-like device that generate them from the current time, a secret pin and a cryptographic hash serves a quite different purpose;
The idea is that if you force people to have long, complicated passwords, then they either write them down, use the same password on multiple sites, or both.
By using an additional one-time password, the bank makes sure that there's *two* things identifying the user logging in. One, the user knows the secret pin. (which is typically simple 4-digit or so.) and two, the user is in posession of the sheet-of-codes/calculator-thingie.
Increases security quite a bit, because it's no longer a threat if someone for example hacks the users computer and installs a keylogger or similar device. Sure that attacker will then learn the pin, but the attacker will then *also* need to break into the house of the victim or otherwise acquire the list of one-time-passwords. So at the very least you've eliminated the large group of attackers which have no physical proximity to the victim.