Entries Tagged "banking"

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Company Continues Bad Information Security Practices

Stories about thefts of personal data are dime-a-dozen these days, and are generally not worth writing about.

This one has an interesting coda, though.

An employee hoping to get extra work done over the weekend printed out 2004 payroll information for hundreds of SafeNet’s U.S. employees, snapped it into a briefcase and placed the briefcase in a car.

The car was broken into over the weekend and the briefcase stolen—along with the employees’ names, bank account numbers and Social Security numbers that were on the printouts, a company spokeswoman confirmed yesterday.

My guess is that most readers can point out the bad security practices here. One, the Social Security numbers and bank account numbers should not be kept with the bulk of the payroll data. Ideally, they should use employee numbers and keep sensitive (but irrelevant for most of the payroll process) information separate from the bulk of the commonly processed payroll data. And two, hard copies of that sensitive information should never go home with employees.

But SafeNet won’t learn from its mistake:

The company said no policies were violated, and that no new policies are being written as a result of this incident.

The irony here is that this is a security company.

Posted on May 10, 2005 at 3:00 PMView Comments

Mitigating Identity Theft

Identity theft is the new crime of the information age. A criminal collects enough personal data on someone to impersonate a victim to banks, credit card companies, and other financial institutions. Then he racks up debt in the person’s name, collects the cash, and disappears. The victim is left holding the bag. While some of the losses are absorbed by financial institutions—credit card companies in particular—the credit-rating damage is borne by the victim. It can take years for the victim to clear his name.

Unfortunately, the solutions being proposed in Congress won’t help. To see why, we need to start with the basics. The very term “identity theft” is an oxymoron. Identity is not a possession that can be acquired or lost; it’s not a thing at all. Someone’s identity is the one thing about a person that cannot be stolen.

The real crime here is fraud; more specifically, impersonation leading to fraud. Impersonation is an ancient crime, but the rise of information-based credentials gives it a modern spin. A criminal impersonates a victim online and steals money from his account. He impersonates a victim in order to deceive financial institutions into granting credit to the criminal in the victim’s name. He impersonates a victim to the Post Office and gets the victim’s address changed. He impersonates a victim in order to fool the police into arresting the wrong man. No one’s identity is stolen; identity information is being misused to commit fraud.

The crime involves two very separate issues. The first is the privacy of personal data. Personal privacy is important for many reasons, one of which is impersonation and fraud. As more information about us is collected, correlated, and sold, it becomes easier for criminals to get their hands on the data they need to commit fraud. This is what’s been in the news recently: ChoicePoint, LexisNexis, Bank of America, and so on. But data privacy is more than just fraud. Whether it is the books we take out of the library, the websites we visit, or the contents of our text messages, most of us have personal data on third-party computers that we don’t want made public. The posting of Paris Hilton’s phone book on the Internet is a celebrity example of this.

The second issue is the ease with which a criminal can use personal data to commit fraud. It doesn’t take much personal information to apply for a credit card in someone else’s name. It doesn’t take much to submit fraudulent bank transactions in someone else’s name. It’s surprisingly easy to get an identification card in someone else’s name. Our current culture, where identity is verified simply and sloppily, makes it easier for a criminal to impersonate his victim.

Proposed fixes tend to concentrate on the first issue—making personal data harder to steal—whereas the real problem is the second. If we’re ever going to manage the risks and effects of electronic impersonation, we must concentrate on preventing and detecting fraudulent transactions.

Fraudulent transactions have nothing to do with the legitimate account holders. Criminals impersonate legitimate users to financial intuitions. That means that any solution can’t involve the account holders. That leaves only one reasonable answer: financial intuitions need to be liable for fraudulent transactions. They need to be liable for sending erroneous information to credit bureaus based on fraudulent transactions.

They can’t claim that the user must keep his password secure or his machine virus free. They can’t require the user to monitor his accounts for fraudulent activity, or his credit reports for fraudulently obtained credit cards. Those aren’t reasonable requirements for most users. The bank must be made responsible, regardless of what the user does.

If you think this won’t work, look at credit cards. Credit card companies are liable for all but the first $50 of fraudulent transactions. They’re not hurting for business; and they’re not drowning in fraud, either. They’ve developed and fielded an array of security technologies designed to detect and prevent fraudulent transactions. They’ve pushed most of the actual costs onto the merchants. And almost no security centers around trying to authenticate the cardholder.

That’s an important lesson. Identity theft solutions focus much too much on authenticating the person. Whether it’s two-factor authentication, ID cards, biometrics, or whatever, there’s a widespread myth that authenticating the person is the way to prevent these crimes. But once you understand that the problem is fraudulent transactions, you quickly realize that authenticating the person isn’t the way to proceed.

Again, think about credit cards. Store clerks barely verify signatures when people use cards. People can use credit cards to buy things by mail, phone, or Internet, where no one verifies the signature or even that you have possession of the card. Even worse, no credit card company mandates secure storage requirements for credit cards. They don’t demand that cardholders secure their wallets in any particular way. Credit card companies simply don’t worry about verifying the cardholder or putting requirements on what he does. They concentrate on verifying the transaction.

This same sort of thinking needs to be applied to other areas where criminals use impersonation to commit fraud. I don’t know what the final solutions will look like, but I do know that once financial institutions are liable for losses due to these types of fraud, they will find solutions. Maybe there’ll be a daily withdrawal limit, like there is on ATMs. Maybe large transactions will be delayed for a period of time, or will require a call-back from the bank or brokerage company. Maybe people will no longer be able to open a credit card account by simply filling out a bunch of information on a form. Likely the solution will be a combination of solutions that reduces fraudulent transactions to a manageable level, but we’ll never know until the financial institutions have the financial incentive to put them in place.

Right now, the economic incentives result in financial institutions that are so eager to allow transactions—new credit cards, cash transfers, whatever—that they’re not paying enough attention to fraudulent transactions. They’ve pushed the costs for fraud onto the merchants. But if they’re liable for losses and damages to legitimate users, they’ll pay more attention. And they’ll mitigate the risks. Security can do all sorts of things, once the economic incentives to apply them are there.

By focusing on the fraudulent use of personal data, I do not mean to minimize the harm caused by third-party data and violations of privacy. I believe that the U.S. would be well-served by a comprehensive Data Protection Act like the European Union. However, I do not believe that a law of this type would significantly reduce the risk of fraudulent impersonation. To mitigate that risk, we need to concentrate on detecting and preventing fraudulent transactions. We need to make the entity that is in the best position to mitigate the risk to be responsible for that risk. And that means making the financial institutions liable for fraudulent transactions.

Doing anything less simply won’t work.

Posted on April 15, 2005 at 9:17 AMView Comments

More on Two-Factor Authentication

Recently I published an essay arguing that two-factor authentication is an ineffective defense against identity theft. For example, issuing tokens to online banking customers won’t reduce fraud, because new attack techniques simply ignore the countermeasure. Unfortunately, some took my essay as a condemnation of two-factor authentication in general. This is not true. It’s simply a matter of understanding the threats and the attacks.

Passwords just don’t work anymore. As computers have gotten faster, password guessing has gotten easier. Ever-more-complicated passwords are required to evade password-guessing software. At the same time, there’s an upper limit to how complex a password users can be expected to remember. About five years ago, these two lines crossed: It is no longer reasonable to expect users to have passwords that can’t be guessed. For anything that requires reasonable security, the era of passwords is over.

Two-factor authentication solves this problem. It works against passive attacks: eavesdropping and password guessing. It protects against users choosing weak passwords, telling their passwords to their colleagues or writing their passwords on pieces of paper taped to their monitors. For an organization trying to improve access control for its employees, two-factor authentication is a great idea. Microsoft is integrating two-factor authentication into its operating system, another great idea.

What two-factor authentication won’t do is prevent identity theft and fraud. It’ll prevent certain tactics of identity theft and fraud, but criminals simply will switch tactics. We’re already seeing fraud tactics that completely ignore two-factor authentication. As banks roll out two-factor authentication, criminals simply will switch to these new tactics.

Security is always an arms race, and you could argue that this situation is simply the cost of treading water. The problem with this reasoning is it ignores countermeasures that permanently reduce fraud. By concentrating on authenticating the individual rather than authenticating the transaction, banks are forced to defend against criminal tactics rather than the crime itself.

Credit cards are a perfect example. Notice how little attention is paid to cardholder authentication. Clerks barely check signatures. People use their cards over the phone and on the Internet, where the card’s existence isn’t even verified. The credit card companies spend their security dollar authenticating the transaction, not the cardholder.

Two-factor authentication is a long-overdue solution to the problem of passwords. I welcome its increasing popularity, but identity theft and bank fraud are not results of password problems; they stem from poorly authenticated transactions. The sooner people realize that, the sooner they’ll stop advocating stronger authentication measures and the sooner security will actually improve.

This essay previously appeared in Network World as a “Face Off.” Joe Uniejewski of RSA Security wrote an opposing position. Another article on the subject was published at SearchSecurity.com.

One way to think about this—a phrasing I didn’t think about until after writing the above essay—is that two-factor authentication solves security problems involving authentication. The current wave of attacks against financial systems are not exploiting vulnerabilities in the authentication system, so two-factor authentication doesn’t help.

Posted on April 12, 2005 at 11:02 AMView Comments

Insider Attack Against Citibank

Insiders are the biggest threat:

The Pune police have unearthed a major siphoning racket involving former and serving callcentre employees.

They allegedly transferred a total of [15 million rupees (US $350,000)] from a multinational bank into their own accounts, opened under fictitious names. The money was used to splurge on luxuries like cars and mobile phones.

The call center was in India. The victim was Citibank.

Posted on April 11, 2005 at 9:14 AMView Comments

Police Foil Bank Electronic Theft

From the BBC:

Police in London say they have foiled one of the biggest attempted bank thefts in Britain.

The plan was to steal £220m ($423m) from the London offices of the Japanese bank Sumitomo Mitsui.

Computer experts are believed to have tried to transfer the money electronically after hacking into the bank’s systems.

Not a lot of detail here, but it seems that the thieves got in using a keyboard recorder. It’s the simple attacks that you have to worry about….

Posted on April 4, 2005 at 12:51 PMView Comments

The Failure of Two-Factor Authentication

Two-factor authentication isn’t our savior. It won’t defend against phishing. It’s not going to prevent identity theft. It’s not going to secure online accounts from fraudulent transactions. It solves the security problems we had ten years ago, not the security problems we have today.

The problem with passwords is that they’re too easy to lose control of. People give them to other people. People write them down, and other people read them. People send them in e-mail, and that e-mail is intercepted. People use them to log into remote servers, and their communications are eavesdropped on. They’re also easy to guess. And once any of that happens, the password no longer works as an authentication token because you can’t be sure who is typing that password in.

Two-factor authentication mitigates this problem. If your password includes a number that changes every minute, or a unique reply to a random challenge, then it’s harder for someone else to intercept. You can’t write down the ever-changing part. An intercepted password won’t be good the next time it’s needed. And a two-factor password is harder to guess. Sure, someone can always give his password and token to his secretary, but no solution is foolproof.

These tokens have been around for at least two decades, but it’s only recently that they have gotten mass-market attention. AOL is rolling them out. Some banks are issuing them to customers, and even more are talking about doing it. It seems that corporations are finally waking up to the fact that passwords don’t provide adequate security, and are hoping that two-factor authentication will fix their problems.

Unfortunately, the nature of attacks has changed over those two decades. Back then, the threats were all passive: eavesdropping and offline password guessing. Today, the threats are more active: phishing and Trojan horses.

Here are two new active attacks we’re starting to see:

  • Man-in-the-Middle attack. An attacker puts up a fake bank website and entices user to that website. User types in his password, and the attacker in turn uses it to access the bank’s real website. Done right, the user will never realize that he isn’t at the bank’s website. Then the attacker either disconnects the user and makes any fraudulent transactions he wants, or passes along the user’s banking transactions while making his own transactions at the same time.

  • Trojan attack. Attacker gets Trojan installed on user’s computer. When user logs into his bank’s website, the attacker piggybacks on that session via the Trojan to make any fraudulent transaction he wants.

See how two-factor authentication doesn’t solve anything? In the first case, the attacker can pass the ever-changing part of the password to the bank along with the never-changing part. And in the second case, the attacker is relying on the user to log in.

The real threat is fraud due to impersonation, and the tactics of impersonation will change in response to the defenses. Two-factor authentication will force criminals to modify their tactics, that’s all.

Recently I’ve seen examples of two-factor authentication using two different communications paths: call it “two-channel authentication.” One bank sends a challenge to the user’s cell phone via SMS and expects a reply via SMS. If you assume that all your customers have cell phones, then this results in a two-factor authentication process without extra hardware. And even better, the second authentication piece goes over a different communications channel than the first; eavesdropping is much, much harder.

But in this new world of active attacks, no one cares. An attacker using a man-in-the-middle attack is happy to have the user deal with the SMS portion of the log-in, since he can’t do it himself. And a Trojan attacker doesn’t care, because he’s relying on the user to log in anyway.

Two-factor authentication is not useless. It works for local login, and it works within some corporate networks. But it won’t work for remote authentication over the Internet. I predict that banks and other financial institutions will spend millions outfitting their users with two-factor authentication tokens. Early adopters of this technology may very well experience a significant drop in fraud for a while as attackers move to easier targets, but in the end there will be a negligible drop in the amount of fraud and identity theft.

This essay will appear in the April issue of Communications of the ACM.

Posted on March 15, 2005 at 7:54 AMView Comments

Identity Theft out of Golf Lockers

When someone goes golfing in Japan, he’s given a locker in which to store his valuables. Generally, and at the golf course in question, these are electronic combination locks. The user selects a code himself and locks his valuables. Of course, there’s a back door—a literal one—to the lockers, in case someone forgets his unlock code. Furthermore, the back door allows the administrator of these lockers to read all the codes to all the lockers.

Here’s the scam: A group of thieves worked in conjunction with the locker administrator to open the lockers, copy the golfers’ debit cards, and replace them in their wallets and in their lockers before they were done golfing. In many cases, the golfers used the same code to lock their locker as their bank card PIN, so the thieves got those as well. Then the thieves stole a lot of money from multiple ATMs.

Several factors make this scam even worse. One, unlike the U.S., ATM cards in Japan have no limit. You can literally withdraw everything out of the account. Two, the victims don’t know anything until they find out they have no money when they use their card somewhere. Three, the victims, since they play golf at these expensive courses, are
usually very rich. And four, unlike the United States, Japanese banks do not guarantee loss due to theft.

Posted on March 1, 2005 at 9:20 AMView Comments

Bank Sued for Unauthorized Transaction

This story is interesting:

A Miami businessman is suing Bank of America over $90,000 he says was stolen from his online banking account in a case that highlights the thorny question of who is responsible when a customer’s computer is hacked into.

The typical press coverage of this story is along the lines of “Bank of America sued because customer’s PC was hacked.” But that’s not it. Bank of America is being sued because they allowed an unauthorized transaction to occur, and they’re not making good on that mistake. The transaction happened to occur because the customer’s PC was hacked.

I know nothing about the actual suit and its merits, but this is a problem that is not going away. And while I think that banks should not be held responsible for what’s on their customers’ machines, they should be held responsible for allowing unauthorized transactions to occur. The bank’s internal systems, however set up, for whatever reason, permitted the fraudulent transaction.

There is a simple economic incentive problem here. As long as the banks are not responsible for financial losses from fraudulent transactions over the Internet, banks have no incentive to improve security. But if banks are held responsible for these transactions, you can bet that they won’t allow such shoddy security.

Posted on February 9, 2005 at 8:00 AMView Comments

Bank Mandates Insecure Browser

The Australian bank Suncorp has just updated its terms and conditions for Internet banking. They have a maximum withdrawal limit, hint about a physical access token, and require customers to use the most vulnerability-laden browser:

“suitable software” means Internet Explorer 5.5 Service Pack 2 or above or Netscape Navigator 6.1 or above running on Windows 98/ME/NT/2000/XP with anti-virus software or other software approved by us.

Posted on February 7, 2005 at 8:00 AMView Comments

Two-Factor Authentication with Cell Phones

Here’s a good idea:

ASB and Bank Direct’s internet banking customers will need to have their cellphone close to hand if they want to use the net to transfer more than $2500 into another account from December.

ASB technology and operations group general manager Clayton Wakefield announced the banks would be the first in New Zealand to implement a “two factor authentication” system to shut out online fraudsters, unveiling details of the service on Friday.

After logging on to internet banking, customers who want to remit more than $2500 into a third party account will receive an eight-digit text message to their cellphone, which they will need to enter online within three minutes to complete the transaction.

It’s more secure than a simple username and password. It’s easy to implement, with no extra hardware required (assuming your customers already have cellphones). It’s easy for the customers to understand and to do. What’s not to like?

Posted on November 23, 2004 at 9:41 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.