Matt Blaze's
Science, Security, Curiosity
Archives: 30 September 2009 - 28 February 2011

If there is one area where the Web and Internet publishing is truly fulfilling its promise, it has to be the free and open availability of scholarly research from all over the world, to anyone who cares to study it. Today's academic does not just publish or perish, but does so on the Web first. This has made science and scholarship not only more democratic -- no journal subscriptions or university library access required to participate -- but faster and better.

And many of the most prominent scientific and engineering societies are doing everything in their power to put a stop to it. They want to get paid first.

I've written here before about the way certain major technical societies use regressive, coercive copyright policies to obtain from authors exclusive rights to the papers that appear at the conferences and in the journals that they organize. These organizations, rooted in a rapidly disappearing print-based publishing economy, believe that they naturally "own" the writings that (unpaid) authors, editors and reviewers produce. They insist on copyright control as a condition of publication, arguing that the sale of conference proceedings and journal subscriptions provides an essential revenue stream that subsidizes their other good works. But this income, however well it might be used, has evolved into an ill-gotten entitlement. We write scientific papers first and last because we want them read. When papers were disseminated solely in print form it might have been reasonable to expect authors to donate the copyright in exchange for production and distribution. Today, of course, this model seems, at best, quaintly out of touch with the needs of researchers and academics who no longer expect or tolerate the delay and expense of seeking out printed copies of far-flung documents. We expect to find on it on the open web, and not hidden behind a paywall, either.

In my field, computer science (the very field which, ironically, created all this new publishing technology in the first place), some of the most restrictive copyright policies can be found in the two largest and oldest professional societies: the ACM and the IEEE.

Fortunately, these copyrights have been honored mostly in the breach as far as author-based web publishing has been concerned. Many academics make their papers available on their personal web sites, a practice that a growing number of university libraries, including my own, have begun to formalize by hosting institution-wide web repositories of faculty papers. This practice has flourished largely through a liberal reading of a provision -- a loophole -- in many copyright agreements that allows authors to share "preprint" versions of their papers.

But times may be changing, and not for the better. Some time in January, the IEEE apparently quietly revised its copyright policy to explicitly forbid us authors from sharing the "final" versions of our papers on the web, now reserving that privilege to themselves (available to all comers, for the right price). I found out about this policy change in an email sent to all faculty at my school from our librarian this morning:

February 28, 2011

Dear Faculty,

I am writing to bring to your attention a recent change in IEEE's policy for archiving personal papers within institutional repositories. IEEE altered their policy in January from allowing published versions of articles to be saved in repositories, like ScholarlyCommons, to only allowing pre-published versions. We received no prior notice about this change.

As a result, if you or your students/colleagues publish with IEEE and submit papers to ScholarlyCommons, I am writing to ask that you PLEASE REFRAIN FROM UPLOADING ANY NEW PUBLISHED VERSIONS OF ARTICLES. It is unclear yet whether IEEE material uploaded prior to January already within ScholarlyCommons will need to be removed. Anything new added at this point, however, would be in violation of their new policy.


To be fair to IEEE, the ACM's official policy is at least as bad. Not all technical societies are like this; for example, Usenix, on whose board I serve, manages to thrive despite making all its publications available online for free, no paywall access required.

Enough is enough. A few years ago, I stopped renewing my ACM and IEEE memberships in protest, but that now seems an inadequate gesture. These once great organizations, which exist, remember, to promote the exchange and advancement of scientific knowledge, have taken a terribly wrong turn in putting their own profits over science. The directors and publication board members of societies that adopt such policies have allowed a tunnel vision of purpose to sell out the interests of their members. To hell with them.

So from now on, I'm adopting my own copyright policies. In a perfect world, I'd simply refuse to publish in IEEE or ACM venues, but that stance is complicated by my obligations to my student co-authors, who need a wide range of publishing options if they are to succeed in their budding careers. So instead, I will no longer serve as a program chair, program committee member, editorial board member, referee or reviewer for any conference or journal that does not make its papers freely available on the web or at least allow authors to do so themselves.

Please join me. If enough scholars refuse their services as volunteer organizers and reviewers, the quality and prestige of these closed publications will diminish and with it their coercive copyright power over the authors of new and innovative research. Or, better yet, they will adapt and once again promote, rather than inhibit, progress.

Update 2 March 2011: There's been quite a response to this post; I seem to have hit a high-pressure reservoir of resentment against these anti-science publishing policies. But several people have written me defending ACM's copyright transfer in particular as being "not as bad", since authors are permitted to post an "author prepared" version on their own web sites if they choose. Yes, a savvy ACM author can prepare a special version and hack around the policy. But the copyright remains with ACM, and the authoritative reviewed final manuscript stays hidden behind the ACM paywall.

Until that changes, I'll confine my service to open-access conferences such as those organized by Usenix.

Update 4 March 2011: I'm told that some ACM sub-groups (such as SIGCOMM) have negotiated non-paywalled access to their conferences' proceedings. So conference organizers and small groups really can have an impact here! Protest is not futile.

Update 8 March 2011: A prominent member of the ACM asserted to me that copyright assignment and putting papers behind the ACM's centralized "digital library" paywall is the best way to ensure their long-term "integrity". That's certainly a novel theory; most computer scientists would say that wide replication, not centralization, is the best way to ensure availability, and that a centrally-controlled repository is more subject to tampering and other mischief than a decentralized and replicated one. Usenix's open-access proceedings, by the way, are archived through the Stanford LOCKSS project. Paywalls are poor way to ensure permanence.

Update 9 March 2011: David A. Hodges, IEEE VP of Publication Products and Services just sent me a (for some reason in PDF format) "clarifying" the new policy. He confirms that IEEE authors are still permitted to post a pre-publication version on their own (or their employer's) web site, but are now (as of January) prohibited from posting the authoritative "published" PDF version, which will be available exclusively from the IEEE paywall. (You can read his note here [pdf]).

Still no word on whether there's a reason for this policy change other than the obvious rent-seeking behavior that it appears to be. According to this FAQ [pdf], the reason for the policy change is to "exercise better control over IEEE's intellectual property". Which is exactly the problem.

A couple of years ago Jutta Degener and I became the first people to solve James Randi's $1,000,000 paranormal challenge. We derived, from thousands of miles away, the secret contents of a locked box held in Randi's offices set up to test whether psychic "remote viewing" was possible. Not being actual psychics, we had to exploit a weak home-brewed cryptographic commitment scheme that Randi had cooked up to authenticate the box's contents rather than the paranormal powers he was hoping to test for, but we did correctly figure out that the box contained a compact disk. And being nice people, we never formally asked for the million bucks, although we did have a bit of fun blogging about the cryptologic implications of psychic testing, which you can read here.

Our feat of "psychic cryptanalysis" got a bit more attention than I had expected given that our earthly cryptographic abilities are anything but paranormal, but you never know where the Internet will take things. But I was even more surprised when someone recently sent me a link to this final exam from a contracts course at the Stetson University College of Law [pdf].

Now, my mother definitely didn't raise me to be a law school exam question, and yet there we are, playing a staring role in the question on the forth page. I have no idea whether to be flattered or horrified, but for the record (especially in case the IRS is reading), we never asked for or received the million dollars. And I've definitely never been been to an Alaskan psychic's convention.

The one thing I'm sure of is that Prof. Jimenez (who I've never met) will be making a guest appearance on some exam of mine in the near future. In a perfect world, he might play a role in a question involving copyright infringement, defamation, and false-light privacy, but since I teach computer science, not law, something about operating systems will probably have to do instead.

Fair warning: If I give a talk --- at your conference, lecture series, meeting, whatever -- and you ask me for "a copy of my presentation" I'm probably going to refuse. It isn't personal and I'm not trying to be difficult. It's just that I have nothing that I can sensibly give you.

Many speakers these days make their visual aids available, but I don't. I don't always use any, but even when I do, they just aren't intended to be comprehensible outside the context of my talk. Creating slides that can serve double duty as props for my talk and as a stand-alone summary of the content is, I must confess, a talent that lies beyond the limits of my ability. Fortunately, when I give a talk I've usually also written something about the subject too, and almost all my papers are freely available to all. Unlike my slides, I try to write in a way that makes sense even without me standing there explaining things while you read.

"Presentation software" like PowerPoint (and KeyNote and others of that ilk) has blurred the line between mere visual aids and the presentations themselves. I've grown to loathe PowerPoint, not because of particular details that don't suit me (though it would be nice if it handled equations more cleanly), but because it gets things precisely backwards. When I give a talk, I want to be in control. But the software has other ideas.

PowerPoint isn't content to sit in the background and project the occasional chart, graph or bullet list. It wants to organize the talk, to manage the presentation. There's always going to be a slide up, whether you need it there or not. Want to skip over some material? OK, but only by letting the audience watch as you fast-forward awkwardly through the pre-set order. Change the order around to answer a question? Tough -- should have thought of that before you started. You are not the one in charge here, and don't you forget it.

When I give a talk, I like to rely on a range of tools -- my voice, hand gestures, props, live demos, and, yes, PowerPoint slides. I tend to mix and match. In other words, from PowerPoint's perspective, I'm usually using it badly, even abusively. I often ignore the slides for minutes on end, or digress on points only elliptically hinted at on the screen. When I really get going, the sides are by themselves useless or, worse, outright misleading. Distributing them separately would at best be an invitation to take them hopelessly and confusingly out of context, and at worst, a form of perjury.

Unfortunately, "PowerPoint" has become synonymous these days with "presentation", but I just don't work that way. Maybe you don't work that way either. There's no one-size-fits-all way to give a talk, or even a one-size-fits-me way. So when I'm asked for my slides, I must politely refuse and offer my papers as a substitute (an idea I owe to the great Edward Tufte).

Fortunately, I'm senior enough (or have a reputation for being cranky enough) that I can usually get away with refusing. Sometimes, though, when pressed hard, I'll give in and send these slides [pdf].

Addendum 26 November 2010: This post sure has struck a (perhaps dissonant) chord somewhere, especially for a long holiday weekend. I'm grateful to all who've emailed, blogged, and tweeted.

Several people have thoughtfully suggested their favorite alternatives to PowerPoint (Prezi seems to be the popular choice), which I'll certainly check out. And for the record, yes, I know about (and use when I can) PowerPoint's "presenter" mode, which improves control over the audience display. Unfortunately, both alternative software and presenter mode, while improvements, are at best unreliable, since they assume a particular configuration on the projecting computer. It often isn't possible to project from a personal laptop (especially in conferences run on tight schedules), leaving us at the mercy of whatever is at the podium. And that often means PowerPoint in single-screen mode.

In any case, while there is certainly room for me to improve my mastery of PowerPoint and its alternatives, this wouldn't solve the basic problem, which is that, in my case at least, my slides -- when I use them at all -- aren't the content. They won't help you understand things much more than would any of the other stuff I also happen to bring up on stage with me, like, say, my shoes (which you can't have, either). But you're welcome to my papers.

I'll be the first witness at this morning's (6/24/10) House Judiciary Committee hearing on ECPA Reform and the Revolution in Location-Based Technology, which, for DC locals, will start at 10am in room 2233 of the Rayburn building.

My testimony [pdf] will focus on the technical: how modern cell phones and wireless services calculate location, and how accurately they can track and record users' positions and movements. This is all in the context of surveillance: when the government gets a pen register order against a cell phone, for example, what information do (or should) they get about the target's location and movements compared with other kinds of tracking technology?

Other witnesses will include (among others) a special agent (from the Tennessee Bureau of Investigation) who does electronic surveillance, and a federal magistrate judge who has to sort out the legal issues when the government requests tracking information about a suspect. The hearing promises to be an interesting glimpse into how location tracking actually works in criminal investigations.

No idea if the hearing will be shown via a webcast or C-SPAN coverage.

Update 6/28/10: The hearing was interesting, and I especially enjoyed Chairman Nadler's line of questions to me about how the technology works and about the records kept by carriers. Unfortunately, video of the hearing doesn't appear to be available online anywhere, at least at the moment.
Update 5/16/12: An updated version of my testimony is available at, as a statement for the record at a house hearing on the "GPS Act".

Back in 1995, Bruce Schneier asked me to write an "afterword" for the second edition of Applied Cryptography. Perhaps to his chagrin, I couldn't think of any better way to sum up a book about cryptography than to dismiss what was then a popular delusion about the subject: that it, above all else, held the secret for securing computers.

1995 now seems like a long time ago, technically and culturally. The Web was barely around. Highly connected people had fax lines at home. The Soviet Union had only recently dissolved. I could see the World Trade Center from my bedroom window.

Essays written that long ago, especially those about rapidly changing technology, can be a bit embarrassing to read -- conspicuously oblivious to some fast approaching meteorite that would shortly make the author's basic assumptions extinct. Or they might seem retrospectively obvious and trite: war is bad, puppies are cute, and computers are insecure.

And so it was with some trepidation that I recently dusted off my copy of Bruce's book and found myself staring at my thoughts on cryptography from the previous century.

A decade ago, I observed that commercial certificate authorities protect you from anyone from whom they are unwilling to take money. That turns out to be wrong; they don't even do that much.

SSL certificates are the primary mechanism for ensuring that secure web sites -- those displaying that reassuring "padlock" icon in the address bar -- really are who they purport to be. In order for your browser to display the padlock icon, a web site must first present a "certificate", digitally signed by a trusted "root" authority, that attests to its identity and encryption keys.

Unfortunately, through a confluence of sloppy design, naked commercial maneuvering, and bad user interfaces, today's web browsers have evolved to accept certificates issued by a surprisingly large number of root authorities, from tiny, obscure businesses to various national governments. And a certificate from any one of them is usually sufficient to bless any web connection as being "secure".

What this means is that an eavesdropper who can obtain fake certificates from any certificate authority can successfully impersonate every encrypted web site someone might visit. Most browsers will happily (and silently) accept new certificates from any valid authority, even for web sites for which certificates had already been obtained. An eavesdropper with fake certificates and access to a target's internet connection can thus quietly interpose itself as a "man-in-the-middle", observing and recording all encrypted web traffic traffic, with the user none the wiser.

But how much of a threat is this in practice? Are there really eavesdroppers out there -- be they criminals, spies, or law enforcement agencies -- using bogus certificates to intercept encrypted web traffic? Or is this merely idle speculation, of only theoretical concern?

A paper published today by Chris Soghoian and Sid Stamm [pdf] suggests that the threat may be far more practical than previously thought. They found turnkey surveillance products, marketed and sold to law enforcement and intelligence agencies in the US and foreign countries, designed to collect encrypted SSL traffic based on forged "look-alike" certificates obtained from cooperative certificate authorities. The products (apparently available only to government agencies) appear sophisticated, mature, and mass-produced, suggesting that "certified man-in-the-middle" web surveillance is at least commonplace and widespread enough to support an active vendor community. Wired's Ryan Singel reports in depth here.

It's worth pointing out that, from the perspective of a law enforcement or intelligence agency, this sort of surveillance is far from ideal. A central requirement for most government wiretapping (mandated, for example, in the CALEA standards for telephone interception) is that surveillance be undetectable. But issuing a bogus web certificate carries with it the risk of detection by the target, either in real-time or after the fact, especially if it's for a web site already visited. Although current browsers don't ordinarily detect unusual or suspiciously changed certificates, there's no fundamental reason they couldn't (and the Soghoian/Stamm paper proposes a Firefox plugin to do just that). In any case, there's no reliable way for the wiretapper to know in advance whether the target will be alerted by a browser that scrutinizes new certificates.

Also, it's not clear how web interception would be particularly useful for many of the most common law enforcement investigative scenarios. If a suspect is buying books or making hotel reservations online, it's usually a simple (and legally relatively uncomplicated) matter to just ask the vendor about the transaction, no wiretapping required. This suggests that these products may be aimed less at law enforcement than at national intelligence agencies, who might be reluctant (or unable) to obtain overt cooperation from web site operators (who may be located abroad).

Whether this kind of surveillance is currently widespread or not, Soghoian and Stamm's paper underscores the deeply flawed mess that the web certificate model has become. It's time to design something better.

It's been a frighteningly confusing week for frequent flyers (and confirmed cowards) like me. First we had the Underpants Bomber, his Christmas-day attempt to take down a Detroit-bound flight thwarted by slow-acting chemistry and quick-thinking passengers. Next -- within a day -- came inexplicable new regulations that seemed designed more to punish the rest of us than to discourage future acts of terrorism. The new rules were unsettling not just because they seemed as laughably ineffective as they were inconvenient, but because they suggested that the authorities had no idea what to do, no real process for analyzing and reacting to potential new threats. As the Economist was moved to write, "the people who run America's airport security apparatus appear to have gone insane".

A few days later the TSA, to its credit, rolled back some of the more arbitrarily punitive restrictions -- in-flight entertainment systems can now be turned back on, and passengers are, at the airline's discretion, again permitted to use the toilets during the last hour of flight.

But while a degree of sanity may have returned to some of the rules, the TSA's new security philosophy appears to yield significant advantage to attackers. The current approach may actually make us more vulnerable to disruption and terror now than we were before.

If you can climb a fifteen foot ladder and fit through a two foot diameter hole, you can, with a bit of advance planning, take an extensive "top-to-bottom" tour of a Titan II ICBM launch complex, complete with missile silo and missile. Best of all, you no longer have to trespass or join the Air Force to do it.

And so I just returned from Sahuarita, AZ and the Titan Missile Museum, a place known during most of the cold war as SMS Launch Site 571-7. I spent the better part of the day beneath the surface of the earth, part of a group of six hardy nuclear tourists under the direction of Lt. Col. Chuck Smith (USAF, retired, a former "missileer" at the site), exploring the nuts, bolts and welds of Armageddon.

At the peak of the cold war, there were over 1,000 nuclear missiles in buried silos located throughout sparsely populated areas of the continental United States, all fueled and ready to be launched toward the Soviet Union on a few minutes notice. From 1963 through 1984, this included 54 Titan II missiles at sites in Arizona, Arkansas and Kansas, each equipped with a W-53 warhead capable of delivering a nine megaton thermonuclear yield. Nine megatons is horrifically destructive even by the outsized standards of atomic bombs, capable of leveling a good size city in a single blast. And the Soviets had at least as many similar weapons aimed right back at us.

How did we keep from blowing ourselves up for all those years?

This week in Chicago, Micah Sherr, Gaurav Shah, Eric Cronin, Sandy Clark, and I have a paper at the ACM Computer and Communications Security Conference (CCS) that's getting a bit more attention than I expected. The paper, Can They Hear Me Now? A Security Analysis of Law Enforcement Wiretaps [pdf] examines the standard "lawful access" protocols used to deliver intercepted telephone (and some Internet) traffic to US law enforcement agencies. Picking up where our 2004 analysis of wireline loop extender wiretaps [pdf] left off, this paper looks at the security and reliability of the latest communications surveillance standards, which were mandated by the 1994 Communications Assistance for Law Enforcement Act (CALEA). The standards, it turns out, can leave wiretaps vulnerable to manipulation and denial of service by surveillance targets who employ relatively simple technical countermeasures.

Of particular concern to law enforcement and others who rely on wiretap evidence is the fact that the protocols can be prevented not just from collecting accurate call content (which can already be obscured by a target using encryption), but also from collecting the metadata record -- who called whom and when. Metadata-only taps (called "pen registers" for historical reasons) make up more than 90% of legal wiretaps in the US. Call metadata, which over time reveals a suspect's "community of interest" and behavior patterns, can be more revealing to an investigator than the content. Many agencies use software that automatically aggregates and analyzes call metadata to discover the members (and structure) of suspected criminal networks.

The wiretap standard, called ANSI J-STD-025, was originally designed to cover only the low-bandwidth voice telephone services that existed in the early 1990's. But as the communications services that law enforcement agencies might want to tap have expanded -- think SMS, 3G internet, VoIP, and so on -- the standard has been "patched" to allow the delivery of more and more different kinds of traffic. Unfortunately, many of these new services are a poor fit for the tapping architecture, especially in the way status messages are encoded for delivery to law enforcement and in the way backhaul bandwidth is provisioned. In particular, many modern services make it possible for a wiretap target to generate messages that saturate the relatively low bandwidth "call data channels" between the telephone company and the government, without affecting his or her own services. Worse, these channels are shared among all the taps in a particular central office, so a single person employing countermeasures can suppress wiretaps of other targets as well.

Just to be clear, we don't suggest that anyone actually do these things in the hopes of thwarting a government wiretap. Aside from being somewhat technically difficult, there would be no way to be sure that the countermeasures were actually working. And I know of no evidence that criminals are actually using these techniques today. (Of course, a determined and technically savvy criminal could prove me wrong about this.)

The real problem is that these protocols -- used in the most serious criminal investigations -- were apparently designed and deployed (and mandated in virtually every communications switch in the US) without first subjecting them to a meaningful security analysis. They were engineered to work well in the average case, but ignored the worst case of an adversary trying to create conditions unfavorable to the eavesdropper. And as the services for which these protocols are used have expanded, they've created a wider range of edge conditions, with more opportunities for manipulation and mischief.

That's a familiar theme for security engineers, and the CALEA wiretap standard is hardly the first example of a serious protocol being deployed without considering what an adversary might do. Unfortunately, it probably won't be the last, either.

loop extender I wrote the "Secure Systems" column in the September/October 2009 IEEE Security and Privacy, which is hitting the streets just about now. You can read the full column, "Taking Surveillance out of the Shadows", at [pdf]. The subject, familiar to readers here, is wiretapping gone wrong.

Wiretapping has been controversial lately, often framed, rightly or wrongly, as a zero-sum battle between our right to privacy on the one hand and the needs of law enforcement and intelligence agencies on the other. But in practice, surveillance is about more than policy and civil liberties -- it's also about technology. Reliably intercepting traffic in modern networks can be harder than it sounds. And, time and again, the secret systems relied upon by governments to collect wiretap intelligence and evidence have turned out to have serious problems. Whatever our policy might be, interception systems can -- and do -- fail, even if we don't always hear about it in the public debate.

Indeed, the recent history of electronic surveillance is a veritable catalog of cautionary tales of technological errors, risks and unintended consequences. Sometime mishaps lead to well-publicized violations of the privacy of innocent people. There was, for example, the NSA's disclosure earlier this year that it had been accidently "over-collecting" the communications of innocent Americans. And there was the discovery, in 2005, that the standard interfaces intended to let law enforcement tap cellular telephone traffic had been hijacked by criminals who were using them to tap the mobile phones of hundreds of people in Athens, Greece.

Bugs in tapping technology don't always let in the bad guys; sometimes they keep out the good guys instead. Cryptographers may recall the protocol failures in the NSA's "Clipper" key escrow system [pdf], in which wiretaps could be defeated easily by exploiting a weak authentication scheme during the key setup. More recently, there was the discovery in 2004, by Micah Sherr, Sandy Clark, Eric Cronin and me, that law enforcement intercepts of analog phones can be disabled just by sending a tone down the tapped line [pdf].

What's going on here? It's hard to think of another law enforcement technology beset by as many, or as frequent, flaws as are modern wiretapping systems. No one would tolerate a police force regularly hobbled by exploding guns, self-opening handcuffs, stalled radio cars, or contaminated evidence bags. Yet many of the systems we depend on to track suspected criminals and spies have failed just as spectacularly, if more quietly.

A common factor in these failed systems is that they were designed and deployed largely in secret, away from the kind of engineering scrutiny that, as security engineers know well, is essential for making systems robust. It's a natural enough reflex for law enforcement and intelligence agencies to want to keep their surveillance technology under wraps. But while it may make sense to keep secret who is under surveillance, there's no need to keep secret how. And the track record of current systems suggests a process that is seriously, even dangerously, broken.

Fortunately, unlike some aspects of the debate about wiretapping, reliability isn't a political issue. The flaws in these systems cut across ideology. No one is served by defective technology that spies on the wrong people or that lets criminals, spies, or terrorists evade legal wiretaps. If surveillance is to protect us, it has to come out of the shadows.

Photo: Law enforcement "loop extender" tap for analog phone lines.