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Page 18 of 28

Sarah Palin's E-Mail

People have been asking me to comment about Sarah Palin’s Yahoo e-mail account being hacked. I’ve already written about the security problems with “secret questions” back in 2005:

The point of all these questions is the same: a backup password. If you forget your password, the secret question can verify your identity so you can choose another password or have the site e-mail your current password to you. It’s a great idea from a customer service perspective—a user is less likely to forget his first pet’s name than some random password—but terrible for security. The answer to the secret question is much easier to guess than a good password, and the information is much more public. (I’ll bet the name of my family’s first pet is in some database somewhere.) And even worse, everybody seems to use the same series of secret questions.

The result is the normal security protocol (passwords) falls back to a much less secure protocol (secret questions). And the security of the entire system suffers.

EDITED TO ADD (9/25): Ed Felten on the issue.

Posted on September 24, 2008 at 4:01 PM • View Comments

My LA Times Op Ed on Photo ID Checks at Airport

Opinion

The TSA’s useless photo ID rules

No-fly lists and photo IDs are supposed to help protect the flying public from terrorists. Except that they don’t work.

By Bruce Schneier

August 28, 2008

The TSA is tightening its photo ID rules at airport security. Previously, people with expired IDs or who claimed to have lost their IDs were subjected to secondary screening. Then the Transportation Security Administration realized that meant someone on the government’s no-fly list—the list that is supposed to keep our planes safe from terrorists—could just fly with no ID.

Now, people without ID must also answer personal questions from their credit history to ascertain their identity. The TSA will keep records of who those ID-less people are, too, in case they’re trying to probe the system.

This may seem like an improvement, except that the photo ID requirement is a joke. Anyone on the no-fly list can easily fly whenever he wants. Even worse, the whole concept of matching passenger names against a list of bad guys has negligible security value.

How to fly, even if you are on the no-fly list: Buy a ticket in some innocent person’s name. At home, before your flight, check in online and print out your boarding pass. Then, save that web page as a PDF and use Adobe Acrobat to change the name on the boarding pass to your own. Print it again. At the airport, use the fake boarding pass and your valid ID to get through security. At the gate, use the real boarding pass in the fake name to board your flight.

The problem is that it is unverified passenger names that get checked against the no-fly list. At security checkpoints, the TSA just matches IDs to whatever is printed on the boarding passes. The airline checks boarding passes against tickets when people board the plane. But because no one checks ticketed names against IDs, the security breaks down.

This vulnerability isn’t new. It isn’t even subtle. I wrote about it in 2003, and again in 2006. I asked Kip Hawley, who runs the TSA, about it in 2007. Today, any terrorist smart enough to Google “print your own boarding pass” can bypass the no-fly list.

This gaping security hole would bother me more if the very idea of a no-fly list weren’t so ineffective. The system is based on the faulty notion that the feds have this master list of terrorists, and all we have to do is keep the people on the list off the planes.

That’s just not true. The no-fly list—a list of people so dangerous they are not allowed to fly yet so innocent we can’t arrest them—and the less dangerous “watch list” contain a combined 1 million names representing the identities and aliases of an estimated 400,000 people. There aren’t that many terrorists out there; if there were, we would be feeling their effects.

Almost all of the people stopped by the no-fly list are false positives. It catches innocents such as Ted Kennedy, whose name is similar to someone’s on the list, and Yusuf Islam (formerly Cat Stevens), who was on the list but no one knew why.

The no-fly list is a Kafkaesque nightmare for the thousands of innocent Americans who are harassed and detained every time they fly. Put on the list by unidentified government officials, they can’t get off. They can’t challenge the TSA about their status or prove their innocence. (The U.S. 9th Circuit Court of Appeals decided this month that no-fly passengers can sue the FBI, but that strategy hasn’t been tried yet.)

But even if these lists were complete and accurate, they wouldn’t work. Timothy McVeigh, the Unabomber, the D.C. snipers, the London subway bombers and most of the 9/11 terrorists weren’t on any list before they committed their terrorist acts. And if a terrorist wants to know if he’s on a list, the TSA has approved a convenient, $100 service that allows him to figure it out: the Clear program, which issues IDs to “trusted travelers” to speed them through security lines. Just apply for a Clear card; if you get one, you’re not on the list.

In the end, the photo ID requirement is based on the myth that we can somehow correlate identity with intent. We can’t. And instead of wasting money trying, we would be far safer as a nation if we invested in intelligence, investigation and emergency response—security measures that aren’t based on a guess about a terrorist target or tactic.

That’s the TSA: Not doing the right things. Not even doing right the things it does.

Posted on September 1, 2008 at 5:15 AM • View Comments

UK Electronic Passport Cloned

The headline says it all: “‘Fakeproof’ e-passport is cloned in minutes.”

Does this surprise anyone? This is what I wrote about electronic passports two years ago in The Washington Post:

The other security mechanisms are also vulnerable, and several security researchers have already discovered flaws. One found that he could identify individual chips via unique characteristics of the radio transmissions. Another successfully cloned a chip. The State Department called this a “meaningless stunt,” pointing out that the researcher could not read or change the data. But the researcher spent only two weeks trying; the security of your passport has to be strong enough to last 10 years.

This is perhaps the greatest risk. The security mechanisms on your passport chip have to last the lifetime of your passport. It is as ridiculous to think that passport security will remain secure for that long as it would be to think that you won’t see another security update for Microsoft Windows in that time. Improvements in antenna technology will certainly increase the distance at which they can be read and might even allow unauthorized readers to penetrate the shielding.

Posted on August 8, 2008 at 4:59 AM • View Comments

Man-in-the-Middle Attacks

Last week’s dramatic rescue of 15 hostages held by the guerrilla organization FARC was the result of months of intricate deception on the part of the Colombian government. At the center was a classic man-in-the-middle attack.

In a man-in-the-middle attack, the attacker inserts himself between two communicating parties. Both believe they’re talking to each other, and the attacker can delete or modify the communications at will.

The Wall Street Journal reported how this gambit played out in Colombia:

“The plan had a chance of working because, for months, in an operation one army officer likened to a ‘broken telephone,’ military intelligence had been able to convince Ms. Betancourt’s captor, Gerardo Aguilar, a guerrilla known as ‘Cesar,’ that he was communicating with his top bosses in the guerrillas’ seven-man secretariat. Army intelligence convinced top guerrilla leaders that they were talking to Cesar. In reality, both were talking to army intelligence.”

This ploy worked because Cesar and his guerrilla bosses didn’t know one another well. They didn’t recognize one anothers’ voices, and didn’t have a friendship or shared history that could have tipped them off about the ruse. Man-in-the-middle is defeated by context, and the FARC guerrillas didn’t have any.

And that’s why man-in-the-middle, abbreviated MITM in the computer-security community, is such a problem online: Internet communication is often stripped of any context. There’s no way to recognize someone’s face. There’s no way to recognize someone’s voice. When you receive an e-mail purporting to come from a person or organization, you have no idea who actually sent it. When you visit a website, you have no idea if you’re really visiting that website. We all like to pretend that we know who we’re communicating with—and for the most part, of course, there isn’t any attacker inserting himself into our communications—but in reality, we don’t. And there are lots of hacker tools that exploit this unjustified trust, and implement MITM attacks.

Even with context, it’s still possible for MITM to fool both sides—because electronic communications are often intermittent. Imagine that one of the FARC guerrillas became suspicious about who he was talking to. So he asks a question about their shared history as a test: “What did we have for dinner that time last year?” or something like that. On the telephone, the attacker wouldn’t be able to answer quickly, so his ruse would be discovered. But e-mail conversation isn’t synchronous. The attacker could simply pass that question through to the other end of the communications, and when he got the answer back, he would be able to reply.

This is the way MITM attacks work against web-based financial systems. A bank demands authentication from the user: a password, a one-time code from a token or whatever. The attacker sitting in the middle receives the request from the bank and passes it to the user. The user responds to the attacker, who passes that response to the bank. Now the bank assumes it is talking to the legitimate user, and the attacker is free to send transactions directly to the bank. This kind of attack completely bypasses any two-factor authentication mechanisms, and is becoming a more popular identity-theft tactic.

There are cryptographic solutions to MITM attacks, and there are secure web protocols that implement them. Many of them require shared secrets, though, making them useful only in situations where people already know and trust one another.

The NSA-designed STU-III and STE secure telephones solve the MITM problem by embedding the identity of each phone together with its key. (The NSA creates all keys and is trusted by everyone, so this works.) When two phones talk to each other securely, they exchange keys and display the other phone’s identity on a screen. Because the phone is in a secure location, the user now knows who he is talking to, and if the phone displays another organization—as it would if there were a MITM attack in progress—he should hang up.

Zfone, a secure VoIP system, protects against MITM attacks with a short authentication string. After two Zfone terminals exchange keys, both computers display a four-character string. The users are supposed to manually verify that both strings are the same—”my screen says 5C19; what does yours say?”—to ensure that the phones are communicating directly with each other and not with an MITM. The AT&T TSD-3600 worked similarly.

This sort of protection is embedded in SSL, although no one uses it. As it is normally used, SSL provides an encrypted communications link to whoever is at the other end: bank and phishing site alike. And the better phishing sites create valid SSL connections, so as to more effectively fool users. But if the user wanted to, he could manually check the SSL certificate to see if it was issued to “National Bank of Trustworthiness” or “Two Guys With a Computer in Nigeria.”

No one does, though, because you have to both remember and be willing to do the work. (The browsers could make this easier if they wanted to, but they don’t seem to want to.) In the real world, you can easily tell a branch of your bank from a money changer on a street corner. But on the internet, a phishing site can be easily made to look like your bank’s legitimate website. Any method of telling the two apart takes work. And that’s the first step to fooling you with a MITM attack.

Man-in-the-middle isn’t new, and it doesn’t have to be technological. But the internet makes the attacks easier and more powerful, and that’s not going to change anytime soon.

This essay originally appeared on Wired.com.

Posted on July 15, 2008 at 6:47 AM • View Comments

LifeLock and Identity Theft

LifeLock, one of the companies that offers identity-theft protection in the United States, has been taking quite a beating recently. They’re being sued by credit bureaus, competitors and lawyers in several states that are launching class action lawsuits. And the stories in the media … it’s like a piranha feeding frenzy.

There are also a lot of errors and misconceptions. With its aggressive advertising campaign and a CEO who publishes his Social Security number and dares people to steal his identity—Todd Davis, 457-55-5462—LifeLock is a company that’s easy to hate. But the company’s story has some interesting security lessons, and it’s worth understanding in some detail.

In December 2003, as part of the Fair and Accurate Credit Transactions Act, or Facta, credit bureaus were forced to allow you to put a fraud alert on their credit reports, requiring lenders to verify your identity before issuing a credit card in your name. This alert is temporary, and expires after 90 days. Several companies have sprung up—LifeLock, Debix, LoudSiren, TrustedID—that automatically renew these alerts and effectively make them permanent.

This service pisses off the credit bureaus and their financial customers. The reason lenders don’t routinely verify your identity before issuing you credit is that it takes time, costs money and is one more hurdle between you and another credit card. (Buy, buy, buy—it’s the American way.) So in the eyes of credit bureaus, LifeLock’s customers are inferior goods; selling their data isn’t as valuable. LifeLock also opts its customers out of pre-approved credit card offers, further making them less valuable in the eyes of credit bureaus.

And, so began a smear campaign on the part of the credit bureaus. You can read their points of view in this New York Times article, written by a reporter who didn’t do much more than regurgitate their talking points. And the class action lawsuits have piled on, accusing LifeLock of deceptive business practices, fraudulent advertising and so on. The biggest smear is that LifeLock didn’t even protect Todd Davis, and that his identity was allegedly stolen.

It wasn’t. Someone in Texas used Davis’s SSN to get a $500 advance against his paycheck. It worked because the loan operation didn’t check with any of the credit bureaus before approving the loan—perfectly reasonable for an amount this small. The payday-loan operation called Davis to collect, and LifeLock cleared up the problem. His credit report remains spotless.

The Experian credit bureau’s lawsuit basically claims that fraud alerts are only for people who have been victims of identity theft. This seems spurious; the text of the law states that anyone “who asserts a good faith suspicion that the consumer has been or is about to become a victim of fraud or related crime” can request a fraud alert. It seems to me that includes anybody who has ever received one of those notices about their financial details being lost or stolen, which is everybody.

As to deceptive business practices and fraudulent advertising—those just seem like class action lawyers piling on. LifeLock’s aggressive fear-based marketing doesn’t seem any worse than a lot of other similar advertising campaigns. My guess is that the class action lawsuits won’t go anywhere.

In reality, forcing lenders to verify identity before issuing credit is exactly the sort of thing we need to do to fight identity theft. Basically, there are two ways to deal with identity theft: Make personal information harder to steal, and make stolen personal information harder to use. We all know the former doesn’t work, so that leaves the latter. If Congress wanted to solve the problem for real, one of the things it would do is make fraud alerts permanent for everybody. But the credit industry’s lobbyists would never allow that.

LifeLock does a bunch of other clever things. They monitor the national address database, and alert you if your address changes. They look for your credit and debit card numbers on hacker and criminal websites and such, and assist you in getting a new number if they see it. They have a million-dollar service guarantee—for complicated legal reasons, they can’t call it insurance—to help you recover if your identity is ever stolen.

But even with all of this, I am not a LifeLock customer. At $120 a year, it’s just not worth it. You wouldn’t know it from the press attention, but dealing with identity theft has become easier and more routine. Sure, it’s a pervasive problem. The Federal Trade Commission reported that 8.3 million Americans were identity-theft victims in 2005. But that includes things like someone stealing your credit card and using it, something that rarely costs you any money and that LifeLock doesn’t protect against. New account fraud is much less common, affecting 1.8 million Americans per year, or 0.8 percent of the adult population. The FTC hasn’t published detailed numbers for 2006 or 2007, but the rate seems to be declining.

New card fraud is also not very damaging. The median amount of fraud the thief commits is $1,350, but you’re not liable for that. Some spectacularly horrible identity-theft stories notwithstanding, the financial industry is pretty good at quickly cleaning up the mess. The victim’s median out-of-pocket cost for new account fraud is only $40, plus ten hours of grief to clean up the problem. Even assuming your time is worth $100 an hour, LifeLock isn’t worth more than $8 a year.

And it’s hard to get any data on how effective LifeLock really is. They’ve been in business three years and have about a million customers, but most of them have joined up in the last year. They’ve paid out on their service guarantee 113 times, but a lot of those were for things that happened before their customers became customers. (It was easier to pay than argue, I assume.) But they don’t know how often the fraud alerts actually catch an identity thief in the act. My guess is that it’s less than the 0.8 percent fraud rate above.

LifeLock’s business model is based more on the fear of identity theft than the actual risk.

It’s pretty ironic of the credit bureaus to attack LifeLock on its marketing practices, since they know all about profiting from the fear of identity theft. Facta also forced the credit bureaus to give Americans a free credit report once a year upon request. Through deceptive marketing techniques, they’ve turned this requirement into a multimillion-dollar business.

Get LifeLock if you want, or one of its competitors if you prefer. But remember that you can do most of what these companies do yourself. You can put a fraud alert on your own account, but you have to remember to renew it every three months. You can also put a credit freeze on your account, which is more work for the average consumer but more effective if you’re a privacy wonk—and the rules differ by state. And maybe someday Congress will do the right thing and put LifeLock out of business by forcing lenders to verify identity every time they issue credit in someone’s name.

This essay originally appeared in Wired.com.

Posted on June 17, 2008 at 6:51 AM • View Comments

The ID Divide

Yesterday, the Center for American Progress published its paper on identification and identification technologies: “The ID Divide: Addressing the Challenges of Identification and Authentication in American Society.” I was one of the participants in the project that created this paper, and it’s worth reading.

Among other things, the paper identifies six principles for identification systems:

Achieve real security or other goals
Accuracy
Inclusion
Fairness and equality
Effective redress mechanisms
Equitable financing for systems

From the Executive Summary:

How can these principles be honored in practice? That’s where the “due diligence” process comes into play when considering and implementing identification systems. Due diligence in the financial world of mergers and acquisitions and other important corporate transactions is conducted before a company makes a major investment. Proponents of, say, a merger (or in our case, a new identification program) can err on the side of optimism, concluding too readily that the merger (or new ID program) is clearly the way to go. Thorough due diligence protects against such over-optimism.

In the pages that follow, we apply this due diligence process to some recurring technical problems with current and proposed identification programs. And we discover—as you’ll see toward the end of the report—that ID programs that rely on “shared secrets,” such as Social Security numbers or your mother’s maiden name, are becoming more insecure due to the increased use of identification. Similarly, ID programs based on biometrics such as fingerprints or iris scans are not the “silver bullets” that some proponents claim they are, but rather could become compromised rapidly if deployed in haphazard ways.

We then apply our progressive principles and due diligence insights to two current examples of identification programs. The first details why it would be bad policy to require government-issued photo ID for in-person voting. The second shows the basically sound policy rationale for the Transportation Worker Identification Card, used for workers with access to security-critical port facilities. By examining one identification program that is reasonable, and one that is not, our analysis shows the usefulness of the Progressive Principles for Identification Systems.

I participated in the panel discussion announcing this report, along with Jim Harper (Director of Information Policy Studies at the Cato Institute).

Posted on June 4, 2008 at 6:34 AM • View Comments

Fax Signatures

Aren’t fax signatures the weirdest thing? It’s trivial to cut and paste—with real scissors and glue—anyone’s signature onto a document so that it’ll look real when faxed. There is so little security in fax signatures that it’s mind-boggling that anyone accepts them.

Yet people do, all the time. I’ve signed book contracts, credit card authorizations, nondisclosure agreements and all sorts of financial documents—all by fax. I even have a scanned file of my signature on my computer, so I can virtually cut and paste it into documents and fax them directly from my computer without ever having to print them out. What in the world is going on here?

And, more importantly, why are fax signatures still being used after years of experience? Why aren’t there many stories of signatures forged through the use of fax machines?

The answer comes from looking at fax signatures not as an isolated security measure, but in the context of the larger system. Fax signatures work because signed faxes exist within a broader communications context.

In a 2003 paper, “Economics, Psychology, and Sociology of Security,” Professor Andrew Odlyzko looks at fax signatures and concludes:

Although fax signatures have become widespread, their usage is restricted. They are not used for final contracts of substantial value, such as home purchases. That means that the insecurity of fax communications is not easy to exploit for large gain. Additional protection against abuse of fax insecurity is provided by the context in which faxes are used. There are records of phone calls that carry the faxes, paper trails inside enterprises and so on. Furthermore, unexpected large financial transfers trigger scrutiny. As a result, successful frauds are not easy to carry out by purely technical means.

He’s right. Thinking back, there really aren’t ways in which a criminal could use a forged document sent by fax to defraud me. I suppose an unscrupulous consulting client could forge my signature on an non-disclosure agreement and then sue me, but that hardly seems worth the effort. And if my broker received a fax document from me authorizing a money transfer to a Nigerian bank account, he would certainly call me before completing it.

Credit card signatures aren’t verified in person, either—and I can already buy things over the phone with a credit card—so there are no new risks there, and Visa knows how to monitor transactions for fraud. Lots of companies accept purchase orders via fax, even for large amounts of stuff, but there’s a physical audit trail, and the goods are shipped to a physical address—probably one the seller has shipped to before. Signatures are kind of a business lubricant: mostly, they help move things along smoothly.

Except when they don’t.

On October 30, 2004, Tristian Wilson was released from a Memphis jail on the authority of a forged fax message. It wasn’t even a particularly good forgery. It wasn’t on the standard letterhead of the West Memphis Police Department. The name of the policeman who signed the fax was misspelled. And the time stamp on the top of the fax clearly showed that it was sent from a local McDonald’s.

The success of this hack has nothing to do with the fact that it was sent over by fax. It worked because the jail had lousy verification procedures. They didn’t notice any discrepancies in the fax. They didn’t notice the phone number from which the fax was sent. They didn’t call and verify that it was official. The jail was accustomed to getting release orders via fax, and just acted on this one without thinking. Would it have been any different had the forged release form been sent by mail or courier?

Yes, fax signatures always exist in context, but sometimes they are the linchpin within that context. If you can mimic enough of the context, or if those on the receiving end become complacent, you can get away with mischief.

Arguably, this is part of the security process. Signatures themselves are poorly defined. Sometimes a document is valid even if not signed: A person with both hands in a cast can still buy a house. Sometimes a document is invalid even if signed: The signer might be drunk, or have a gun pointed at his head. Or he might be a minor. Sometimes a valid signature isn’t enough; in the United States there is an entire infrastructure of “notary publics” who officially witness signed documents. When I started filing my tax returns electronically, I had to sign a document stating that I wouldn’t be signing my income tax documents. And banks don’t even bother verifying signatures on checks less than $30,000; it’s cheaper to deal with fraud after the fact than prevent it.

Over the course of centuries, business and legal systems have slowly sorted out what types of additional controls are required around signatures, and in which circumstances.

Those same systems will be able to sort out fax signatures, too, but it’ll be slow. And that’s where there will be potential problems. Already fax is a declining technology. In a few years it’ll be largely obsolete, replaced by PDFs sent over e-mail and other forms of electronic documentation. In the past, we’ve had time to figure out how to deal with new technologies. Now, by the time we institutionalize these measures, the technologies are likely to be obsolete.

What that means is people are likely to treat fax signatures—or whatever replaces them—exactly the same way as paper signatures. And sometimes that assumption will get them into trouble.

But it won’t cause social havoc. Wilson’s story is remarkable mostly because it’s so exceptional. And even he was rearrested at his home less than a week later. Fax signatures may be new, but fake signatures have always been a possibility. Our legal and business systems need to deal with the underlying problem—false authentication—rather than focus on the technology of the moment. Systems need to defend themselves against the possibility of fake signatures, regardless of how they arrive.

This essay previously appeared on Wired.com.

EDITED TO ADD (6/3): 2005 story, “Federal Jury Convicts N.Y. Attorney of Faking Judge’s Order.”

Posted on June 3, 2008 at 7:01 AM • View Comments

FAA Badges Missing

I don’t know how big a deal this really is, but it is amusing nonetheless:

According to the investigation, 122 Federal Aviation Administration safety inspector badges have been stolen or lost in the past five years. The credentials are one of the few forms of identification that give complete and unfettered access to airport facilities, including the cockpits of planes in flight.

“The FAA badge is probably of all the badges just as dangerous if not more so than any other,” aviation expert Denny Kelly said.

Kelly, a former commercial pilot and a private investigator, said the badge can give a person free access to nearly every secure area of an airport.

“The FAA badge allows you not only on one airline, plus getting through security, it allows you to get on any airline, any airplane, anyplace,” he said.

Posted on March 11, 2008 at 11:14 AM • View Comments

Israel Implementing IFF System for Commercial Aircraft

Israel is implementing an IFF (identification, friend or foe) system for commercial aircraft, designed to differentiate legitimate planes from terrorist-controlled planes.

The news article implies that it’s a basic challenge-and-response system. Ground control issues some kind of alphanumeric challenge to the plane. The pilot types the challenge into some hand-held computer device, and reads back the reply. Authentication is achieved by 1) physical possession of the device, and 2) typing a legitimate PIN into the device to activate it.

The article talks about a distress mode, where the pilot signals that a terrorist is holding a gun to his head. Likely, that’s done by typing a special distress PIN into the device, and reading back whatever the screen displays.

The military has had this sort of system—first paper-based, and eventually computer-based—for decades. The critical issue with using this on commercial aircraft is how to deal with user error. The system has to be easy enough to use, and the parts hard enough to lose, that there won’t be a lot of false alarms.

Posted on March 10, 2008 at 12:24 PM • View Comments