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Why Don't NFL Teams Encrypt Their Signals Better?

September 14, 2007 by

Yesterday the National Football League punished the New England Patriots and their coach, Bill Belichick, for videotaping an opposing team’s defensive signals. The signals in question are used by coaches to tell their on-field defensive unit how to line up and which tactics to use for the next play. The coach typically makes hand signals and arm movements that the on-field players know how to interpret. (The offense also needs to send signals to players from the sidelines before each play, but they use radios.) The opposition gets an advantage if they know what play is coming, so they will try to figure out what the signals mean.

This is essentially a weak form of cryptography. The coaches apply a kind of encryption to translate the desired play into a ciphertext, which is a sequence of hand and arm movements. They transmit the ciphertext (by making the indicated movements) to the on-field players, who then decrypt it, recovering the original play that the coaches wanted to send. An adversary who can see the ciphertext is supposed to be unable to recover the original message.

I don’t know what systems NFL teams use, but Belichick and the Patriots apparently thought they had a chance of breaking their opponents’ code.

There’s an interesting technical problem here: how to encrypt defensive plays into sideline signals securely, in a way that’s practical for real coaches and players in a game situation. I can think of at least one solution that is secure and practical. (Exercise for geeky readers: How would you do this?)

You might think that any solution would be too complicated for a mere football player to decode. If you think that, you’re underestimating the players involved. NFL defensive captains already cope with complex information and plans, and their teams’ current signaling systems already require decoding of symbols. Clever solutions can be pretty simple.

Crypto applies not only to designing a team’s signals, but also to analyzing rivals’ signals. Who will be the first NFL team to hire a cryptographer?

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iPhone Unlocked; Legal Battle Looming?

August 27, 2007 by

In the past few days several groups declared victory in the battle to unlock the iPhone – to make the iPhone work on cellular networks other than AT&T’s. New Jersey teenager George Hotz published instructions (starting here) for a geeks-only unlock procedure involving hardware and software tweaks. An anonymous group called iPhoneSimFree reportedly has an easy all-software unlock procedure which they plan to sell. And a company called UniquePhones was set to sell a remote unlocking service.

(Technical background: The iPhone as initially sold worked only on the AT&T cell network – the device was pretty much useless until you activated AT&T wireless service on it. People figured out quickly that you could immediately cancel the wireless service to get an iPhone that worked only via WiFi; but you couldn’t use it on any other mobile phone/data network. This was not a fundamental technical limitation of the device, but was instead a technological tie designed by Apple to drive business to AT&T.)

Unlocking the iPhone helps everybody, except AT&T, which would prefer not to face competition in selling wireless services to iPhone users. So AT&T, predictably, seem to be sending its lawyers after the unlockers. UniquePhone, via their iphoneunlocking.com site, reports incoming lawyergrams from AT&T regarding “issues such as copyright infringement and illegal software dissemination”; UniquePhones has delayed its product release to consider its options. The iPhoneSimFree members are reportedly keeping anonymous because of legal concerns.

Can AT&T cook up a legal theory justifying a ban on iPhone unlocking? I’ll leave that question to the lawyers. It seems to me, though, that regardless of what the law does say, it ought to say that iPhone unlocking is fine. For starters, the law should hesitate to micromanage what people do with the devices they own. If you want to run different software on your phone, or if you want to use one cell provider rather than another, why should the government interfere?

I’ll grant that AT&T would prefer that you buy their service. Exxon would prefer that you be required to buy gasoline from them, but the government (rightly) doesn’t try to stop you from filling up elsewhere. The question is not what benefits AT&T or Exxon, but what benefits society as a whole. And the strong presumption is that letting the free market operate – letting customers decide which product to buy – is the best and most efficient policy. Absent some compelling argument that iPhone lock-in is actually necessary for the market to operate efficiently, government should let customers choose their cell operator. Indeed, government policy already tries to foster choice of carriers, for example by requiring phone number portability.

Regardless of what AT&T does, its effort to stop iPhone unlocking is likely doomed. Unlocking software is small and easily transmitted. AT&T’s lawyers can stick a few fingers in the dike, but they won’t be able to stop the unlocking software from getting to people who want it. This is yet another illustration that you can’t lock people out of their own digital devices.

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E-Voting Ballots Not Secret; Vendors Don't See Problem

August 20, 2007 by

Two Ohio researchers have discovered that some of the state’s e-voting machines put a timestamp on each ballot, which severely erodes the secrecy of ballots. The researchers, James Moyer and Jim Cropcho, used the state’s open records law to get access to ballot records, according to Declan McCullagh’s story at news.com. The pair say they have reconstructed the individual ballots for a county tax referendum in Delaware County, Ohio.

Timestamped ballots are a problem because polling-place procedures often record the time or sequence of voter’s arrivals. For example, at my polling place in New Jersey, each voter is given a sequence number which is recorded next to the voter’s name in the poll book records and is recorded in notebooks by Republican and Democratic poll watchers. If I’m the 74th voter using the machine today, and the recorded ballots on that machine are timestamped or kept in order, then anyone with access to the records can figure out how I voted. That, of course, violates the secret ballot and opens the door to coercion and vote-buying.

Most e-voting systems that have been examined get this wrong. In the recent California top-to-bottom review, researchers found that the Diebold system stores the ballots in the order they were cast and with timestamps (report pp. 49-50), and the Hart (report pp. 59) and Sequoia (report p. 64) systems “randomize” stored ballots in an easily reversible fashion. Add in the newly discovered ES&S system, and the vendors are 0-for-4 in protecting ballot secrecy.

You’d expect the vendors to hurry up and fix these problems, but instead they’re just shrugging them off.

An ES&S spokeswoman at the Fleishman-Hillard public relations firm downplayed concerns about vote linking. “It’s very difficult to make a direct correlation between the order of the sign-in and the timestamp in the unit,” said Jill Friedman-Wilson.

This is baloney. If you know the order of sign-ins, and you can put the ballots in order by timestamp, you’ll be able to connect them most of the time. You might make occasional mistakes, but that won’t reassure voters who want secrecy.

You know things are bad when questions about a technical matter like security are answered by a public-relations firm. Companies that respond constructively to security problems are those that see them not merely as a PR (public relations) problem but as a technology problem with PR implications. The constructive response in these situations is to say, “We take all security issues seriously and we’re investigating this report.”

Diebold, amazingly, claims that they don’t timestamp ballots – even though they do:

Other suppliers of electronic voting machines say they do not include time stamps in their products that provide voter-verified paper audit trails…. A spokesman for Diebold Election Systems (now Premier Election Solutions), said they don’t for security and privacy reasons: “We’re very sensitive to the integrity of the process.”

You have to wonder why e-voting vendors are so much worse at responding to security flaw reports than makers of other products. Most software vendors will admit problems when they’re real, will work constructively with the problems’ discoverers, and will issue patches promptly. Companies might try PR bluster once or twice, but they learn that bluster doesn’t work and they’re just driving away customers. The e-voting companies seem to make the same mistakes over and over.

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Sony-BMG Sues Maker of Bad DRM

August 8, 2007 by

Major record company Sony-BMG has sued the company that made some of the dangerous DRM (anti-copying) software that shipped on Sony-BMG compact discs back in 2005, according to an Antony Bruno story in Billboard.

Longtime Freedom to Tinker readers will remember that back in 2005 Sony-BMG shipped CDs that opened security holes and invaded privacy when inserted into Windows PCs. The CDs contained anti-copying software from two companies, SunnComm and First4Internet. The companies’ attempts to fix the problems only made things worse. Sony-BMG ultimately had to recall some of the discs, and faced civil suits and government investigations that were ultimately settled. The whole episode must have cost Sony-BMG many millions of dollars. (Alex Halderman and I wrote an academic paper about it.)

One of the most interesting questions about this debacle is who deserved the blame. SunnComm and First4Internet made the dangerous products, but Sony-BMG licensed them and distributed them to the public. It’s tempting to blame the vendors, but the fact that Sony-BMG shipped two separate dangerous products has to be part of the calculus too. There’s plenty of blame to go around.

As it turned out, Sony-BMG took most of the public heat and shouldered most of the financial responsibility. That was pretty much inevitable considering that Sony-BMG had the deepest pockets, was the entity that consumers knew, and had by far the most valuable brand name. The lawsuit looks like an attempt by Sony-BMG to recoup some of its losses.

The suit will frustrate SunnComm’s latest attempt to run from its past. SunnComm had renamed itself as Amergence Group and was trying to build a new corporate image as some kind of venture capitalist or start-up incubator. (This isn’t the first swerve in SunnComm’s direction – the company started out as a booking agency for Elvis impersonators. No, I’m not making that up.) The suit and subsequent publicity won’t help the company’s image any.

The suit itself will be interesting, if it goes ahead. We have long wondered exactly what Sony knew and when, as well as how the decision to deploy the dangerous technology was made. Discovery in the lawsuit will drag all of that out, though it will probably stay behind closed doors unless the case makes it to court. Sadly for the curious public, a settlement seems likely. SunnComm/Amergence almost certainly lacks the funds to fight this suit, or to pay the $12 million Sony-BMG is asking for.

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More California E-Voting Reports Released; More Bad News

August 3, 2007 by

Yesterday the California Secretary of State released the reports of three source code study teams that analyzed the source code of e-voting systems from Diebold, Hart InterCivic, and Sequoia.

All three reports found many serious vulnerabilities. It seems likely that computer viruses could be constructed that could infect any of the three systems, spread between voting machines, and steal votes on the infected machines. All three systems use central tabulators (machines at election headquarters that accumulate ballots and report election results) that can be penetrated without great effort.

It’s hard to convey the magnitude of the problems in a short blog post. You really have read through the reports – the shortest one is 78 pages – to appreciate the sheer volume and diversity of severe vulnerabilities.

It is interesting (at least to me as a computer security guy) to see how often the three companies made similar mistakes. They misuse cryptography in the same ways: using fixed unchangeable keys, using ciphers in ECB mode, using a cyclic redundancy code for data integrity, and so on. Their central tabulators use poorly protected database software. Their code suffers from buffer overflows, integer overflow errors, and format string vulnerabilities. They store votes in a way that compromises the secret ballot.

Some of these are problems that the vendors claimed to have fixed years ago. For example, Diebold claimed (p. 11) in 2003 that its use of hard-coded passwords was “resolved in subsequent versions of the software”. Yet the current version still uses at least two hard-coded passwords – one is “diebold” (report, p. 46) and another is the eight-byte sequence 1,2,3,4,5,6,7,8 (report, p. 45).

Similarly, Diebold in 2003 ridiculed (p. 6) the idea that their software could suffer from buffer overflows: “Unlike a Web server or other Internet enabled applications, the code is not vulnerable to most ‘buffer overflow attacks’ to which the authors [Kohno et al.] refer. This form of attack is almost entirely inapplicable to our application. In the limited number of cases in which it would apply, we have taken the steps necessary to ensure correctness.” Yet the California source code study found several buffer overflow vulnerabilities in Diebold’s systems (e.g., issues 5.1.6, 5.2.3 (“multiple buffer overflows”), and 5.2.18 in the report).

As far as I can tell, major news outlets haven’t taken much notice of these reports. That in itself may be the most eloquent commentary on the state of e-voting: reports of huge security holes in e-voting systems are barely even newsworthy any more.

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