Entries Tagged "academic papers"

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Security-Breach Notification Laws

Interesting study on the effects of security-breach notification laws in the U.S.:

This study surveys the literature on changes in the information security world and significantly expands upon it with qualitative data from seven in-depth discussions with information security officers. These interviews focused on the most important factors driving security investment at their organizations and how security breach notification laws fit into that list. Often missing from the debate is that, regardless of the risk of identity theft and alleged consumer apathy towards notices, the simple fact of having to publicly notify causes organizations to implement stronger security standards that protect personal information.

The interviews showed that security breaches drive information exchange among security professionals, causing them to engage in discussions about information security issues that may arise at their and others’ organizations. For example, we found that some CSOs summarize news reports from breaches at other organizations and circulate them to staff with “lessons learned” from each incident. In some cases, organizations have a “that could have been us” moment, and patch systems with similar vulnerabilities to the entity that had a breach.

Breach notification laws have significantly contributed to heightened awareness of the importance of information security throughout all levels of a business organization and to development of a level of cooperation among different departments within an organization hat resulted from the need to monitor data access for the purposes of detecting, investigating, and reporting breaches. CSOs reported that breach notification duties empowered them to implement new access controls, auditing measures, and encryption. Aside from the organization’s own efforts at complying with notification laws, reports of breaches at other organizations help information officers maintain that sense of awareness.

Posted on December 12, 2007 at 1:53 PMView Comments

Law Review Article on the Problems with Copyright

Excellent article by John Tehranian: “Infringement Nation: Copyright Reform and the Law/Norm Gap“:

By the end of the day, John has infringed the copyrights of twenty emails, three legal articles, an architectural rendering, a poem, five photographs, an animated character, a musical composition, a painting, and fifty notes and drawings. All told, he has committed at least eighty-three acts of infringement and faces liability in the amount of $12.45 million (to say nothing of potential criminal charges). There is nothing particularly extraordinary about John’s activities. Yet if copyright holders were inclined to enforce their rights to the maximum extent allowed by law, he would be indisputably liable for a mind-boggling $4.544 billion in potential damages each year. And, surprisingly, he has not even committed a single act of infringement through P2P file sharing. Such an outcome flies in the face of our basic sense of justice. Indeed, one must either irrationally conclude that John is a criminal infringer—a veritable grand larcenist—or blithely surmise that copyright law must not mean what it appears to say. Something is clearly amiss. Moreover, the troublesome gap between copyright law and norms has grown only wider in recent years.

The point of the article is how, simply by acting normally, all of us are technically lawbreakers many times over every day. When laws are this far outside the social norms, it’s time to change them.

Posted on November 26, 2007 at 6:54 AMView Comments

The Strange Story of Dual_EC_DRBG

Random numbers are critical for cryptography: for encryption keys, random authentication challenges, initialization vectors, nonces, key-agreement schemes, generating prime numbers and so on. Break the random-number generator, and most of the time you break the entire security system. Which is why you should worry about a new random-number standard that includes an algorithm that is slow, badly designed and just might contain a backdoor for the National Security Agency.

Generating random numbers isn’t easy, and researchers have discovered lots of problems and attacks over the years. A recent paper found a flaw in the Windows 2000 random-number generator. Another paper found flaws in the Linux random-number generator. Back in 1996, an early version of SSL was broken because of flaws in its random-number generator. With John Kelsey and Niels Ferguson in 1999, I co-authored Yarrow, a random-number generator based on our own cryptanalysis work. I improved this design four years later—and renamed it Fortuna—in the book Practical Cryptography, which I co-authored with Ferguson.

The U.S. government released a new official standard for random-number generators this year, and it will likely be followed by software and hardware developers around the world. Called NIST Special Publication 800-90 (.pdf), the 130-page document contains four different approved techniques, called DRBGs, or “Deterministic Random Bit Generators.” All four are based on existing cryptographic primitives. One is based on hash functions, one on HMAC, one on block ciphers and one on elliptic curves. It’s smart cryptographic design to use only a few well-trusted cryptographic primitives, so building a random-number generator out of existing parts is a good thing.

But one of those generators—the one based on elliptic curves—is not like the others. Called Dual_EC_DRBG, not only is it a mouthful to say, it’s also three orders of magnitude slower than its peers. It’s in the standard only because it’s been championed by the NSA, which first proposed it years ago in a related standardization project at the American National Standards Institute.

The NSA has always been intimately involved in U.S. cryptography standards—it is, after all, expert in making and breaking secret codes. So the agency’s participation in the NIST (the U.S. Commerce Department’s National Institute of Standards and Technology) standard is not sinister in itself. It’s only when you look under the hood at the NSA’s contribution that questions arise.

Problems with Dual_EC_DRBG were first described in early 2006. The math is complicated, but the general point is that the random numbers it produces have a small bias. The problem isn’t large enough to make the algorithm unusable—and Appendix E of the NIST standard describes an optional work-around to avoid the issue—but it’s cause for concern. Cryptographers are a conservative bunch: We don’t like to use algorithms that have even a whiff of a problem.

But today there’s an even bigger stink brewing around Dual_EC_DRBG. In an informal presentation (.pdf) at the CRYPTO 2007 conference in August, Dan Shumow and Niels Ferguson showed that the algorithm contains a weakness that can only be described as a backdoor.

This is how it works: There are a bunch of constants—fixed numbers—in the standard used to define the algorithm’s elliptic curve. These constants are listed in Appendix A of the NIST publication, but nowhere is it explained where they came from.

What Shumow and Ferguson showed is that these numbers have a relationship with a second, secret set of numbers that can act as a kind of skeleton key. If you know the secret numbers, you can predict the output of the random-number generator after collecting just 32 bytes of its output. To put that in real terms, you only need to monitor one TLS internet encryption connection in order to crack the security of that protocol. If you know the secret numbers, you can completely break any instantiation of Dual_EC_DRBG.

The researchers don’t know what the secret numbers are. But because of the way the algorithm works, the person who produced the constants might know; he had the mathematical opportunity to produce the constants and the secret numbers in tandem.

Of course, we have no way of knowing whether the NSA knows the secret numbers that break Dual_EC-DRBG. We have no way of knowing whether an NSA employee working on his own came up with the constants—and has the secret numbers. We don’t know if someone from NIST, or someone in the ANSI working group, has them. Maybe nobody does.

We don’t know where the constants came from in the first place. We only know that whoever came up with them could have the key to this backdoor. And we know there’s no way for NIST—or anyone else—to prove otherwise.

This is scary stuff indeed.

Even if no one knows the secret numbers, the fact that the backdoor is present makes Dual_EC_DRBG very fragile. If someone were to solve just one instance of the algorithm’s elliptic-curve problem, he would effectively have the keys to the kingdom. He could then use it for whatever nefarious purpose he wanted. Or he could publish his result, and render every implementation of the random-number generator completely insecure.

It’s possible to implement Dual_EC_DRBG in such a way as to protect it against this backdoor, by generating new constants with another secure random-number generator and then publishing the seed. This method is even in the NIST document, in Appendix A. But the procedure is optional, and my guess is that most implementations of the Dual_EC_DRBG won’t bother.

If this story leaves you confused, join the club. I don’t understand why the NSA was so insistent about including Dual_EC_DRBG in the standard. It makes no sense as a trap door: It’s public, and rather obvious. It makes no sense from an engineering perspective: It’s too slow for anyone to willingly use it. And it makes no sense from a backwards-compatibility perspective: Swapping one random-number generator for another is easy.

My recommendation, if you’re in need of a random-number generator, is not to use Dual_EC_DRBG under any circumstances. If you have to use something in SP 800-90, use CTR_DRBG or Hash_DRBG.

In the meantime, both NIST and the NSA have some explaining to do.

This essay originally appeared on Wired.com.

Posted on November 15, 2007 at 6:08 AMView Comments

Architecture and Anti-Terrorist Paranoia

This is really interesting:

(In)Security explores a new design vocabulary in direct response to the climate of fear and paranoia that currently drives the program and aesthetic of much contemporary urban design. The project addresses the current and future state of security in and around the Wall Street financial district, creating viable security alternatives while simultaneously questioning our nation’s current philosophy that security = freedom.

Full paper here.

Posted on November 1, 2007 at 11:47 AMView Comments

Understanding the Black Market in Internet Crime

Here’s a interesting paper from Carnegie Mellon University: “An Inquiry into the Nature and Causes of the Wealth of Internet Miscreants.”

The paper focuses on the large illicit market that specializes in the commoditization of activities in support of Internet-based crime. The main goal of the paper was to understand and measure how these markets function, and discuss the incentives of the various market entities. Using a dataset collected over seven months and comprising over 13 million messages, they were able to categorize the market’s participants, the goods and services advertised, and the asking prices for selected interesting goods.

Really cool stuff.

Unfortunately, the data is extremely noisy and so far the authors have no way to cross-validate it, so it is difficult to make any strong conclusions.

The press focused on just one thing: a discussion of general ways to disrupt the market. Contrary to the claims of the article, the authors have not built any tools to disrupt the markets.

Related blog posts: Gozi and Storm.

Posted on October 29, 2007 at 2:23 PMView Comments

Directed Acyclic Graphs for Crypto Algorithms

Maybe this on directed acyclic graphs is a bit too geeky for the blog, but I think it’s interesting.

The idea of drawing cipher DAGs certainly isn’t new; DAGs are common in cryptographic research and even more common in cryptographic education. What’s new here is the level of automation, minimizing the amount of cipherspecific effort required to build a DAG from a cipher (starting from a typical reference implementation in C or C++) and to visualize the DAG.

My tools are only prototypes at this point. I’m planning to put a cipherdag package online, but I haven’t done so yet, and I certainly can’t claim that the tools have saved time in cryptanalysis. But I think that the tools will save time in cryptanalysis, automating several tedious tasks that today are normally done by hand.

Posted on October 10, 2007 at 2:59 PMView Comments

NASA Using 1960s Cryptanalysis Techniques

Well, sort of.

This paper from the Goddard Space Center, “NiCd Space Battery Test Data Analysis Project, Phase 2 Quarterly Report, 1 Jan. – 30 Apr. 1967,” uses “cryptanalytic techniques”—some sort of tri-gram frequency analysis, I think—to ferret out hidden clues about battery failures.

It’s hard to imagine non-NSA cryptography in the U.S. from the 1960s. Basically, it was all alphabetic stuff. Even rotor machines were highly classified, and absolutely nothing was being done in binary.

Posted on September 27, 2007 at 6:14 AMView Comments

Entering Passwords Through Eye Movement

Interesting:

Reducing Shoulder-surfing by Using Gaze-based Password Entry

Manu Kumar , Tal Garfinkel, Dan Boneh, Terri Winograd

Abstract:

Shoulder-surfing—using direct observation techniques, such as looking over someone’s shoulder, to get passwords, PINs and other sensitive personal information is a problem that has been difficult to overcome. When a user enters information using a keyboard, mouse, touch screen or any traditional input device, a malicious observer may be able to acquire the user’s password credentials. We present EyePassword, a system that mitigates the issues of shoulder surfing via a novel approach to user input. With EyePassword, a user enters sensitive input (password, PIN, etc.) by selecting from an on-screen keyboard using only the orientation of their pupils (i.e. the position of their gaze on screen), making eavesdropping by a malicious observer largely impractical. We present a number of design choices and discuss their effect on usability and security. We conducted user studies to evaluate the speed, accuracy and user acceptance of our approach. Our results demonstrate that gaze-based password entry requires marginal additional time over using a keyboard, error rates are similar to those of using a keyboard and subjects preferred the gaze-based password entry approach over traditional approaches.

Posted on August 30, 2007 at 6:12 AMView Comments

Correspondent Inference Theory

Two people are sitting in a room together: an experimenter and a subject. The experimenter gets up and closes the door, and the room becomes quieter. The subject is likely to believe that the experimenter’s purpose in closing the door was to make the room quieter.

This is an example of correspondent inference theory. People tend to infer the motives—and also the disposition—of someone who performs an action based on the effects of his actions, and not on external or situational factors. If you see someone violently hitting someone else, you assume it’s because he wanted to—and is a violent person—and not because he’s play-acting. If you read about someone getting into a car accident, you assume it’s because he’s a bad driver and not because he was simply unlucky. And—more importantly for this column—if you read about a terrorist, you assume that terrorism is his ultimate goal.

It’s not always this easy, of course. If someone chooses to move to Seattle instead of New York, is it because of the climate, the culture or his career? Edward Jones and Keith Davis, who advanced this theory in the 1960s and 1970s, proposed a theory of “correspondence” to describe the extent to which this effect predominates. When an action has a high correspondence, people tend to infer the motives of the person directly from the action: e.g., hitting someone violently. When the action has a low correspondence, people tend to not to make the assumption: e.g., moving to Seattle.

Like most cognitive biases, correspondent inference theory makes evolutionary sense. In a world of simple actions and base motivations, it’s a good rule of thumb that allows a creature to rapidly infer the motivations of another creature. (He’s attacking me because he wants to kill me.) Even in sentient and social creatures like humans, it makes a lot of sense most of the time. If you see someone violently hitting someone else, it’s reasonable to assume that he’s a violent person. Cognitive biases aren’t bad; they’re sensible rules of thumb.

But like all cognitive biases, correspondent inference theory fails sometimes. And one place it fails pretty spectacularly is in our response to terrorism. Because terrorism often results in the horrific deaths of innocents, we mistakenly infer that the horrific deaths of innocents is the primary motivation of the terrorist, and not the means to a different end.

I found this interesting analysis in a paper by Max Abrahms in International Security. “Why Terrorism Does Not Work” (.PDF) analyzes the political motivations of 28 terrorist groups: the complete list of “foreign terrorist organizations” designated by the U.S. Department of State since 2001. He lists 42 policy objectives of those groups, and found that they only achieved them 7 percent of the time.

According to the data, terrorism is more likely to work if 1) the terrorists attack military targets more often than civilian ones, and 2) if they have minimalist goals like evicting a foreign power from their country or winning control of a piece of territory, rather than maximalist objectives like establishing a new political system in the country or annihilating another nation. But even so, terrorism is a pretty ineffective means of influencing policy.

There’s a lot to quibble about in Abrahms’ methodology, but he seems to be erring on the side of crediting terrorist groups with success. (Hezbollah’s objectives of expelling both peacekeepers and Israel out of Lebanon counts as a success, but so does the “limited success” by the Tamil Tigers of establishing a Tamil state.) Still, he provides good data to support what was until recently common knowledge: Terrorism doesn’t work.

This is all interesting stuff, and I recommend that you read the paper for yourself. But to me, the most insightful part is when Abrahms uses correspondent inference theory to explain why terrorist groups that primarily attack civilians do not achieve their policy goals, even if they are minimalist. Abrahms writes:

The theory posited here is that terrorist groups that target civilians are unable to coerce policy change because terrorism has an extremely high correspondence. Countries believe that their civilian populations are attacked not because the terrorist group is protesting unfavorable external conditions such as territorial occupation or poverty. Rather, target countries infer the short-term consequences of terrorism—the deaths of innocent civilians, mass fear, loss of confidence in the government to offer protection, economic contraction, and the inevitable erosion of civil liberties—(are) the objects of the terrorist groups. In short, target countries view the negative consequences of terrorist attacks on their societies and political systems as evidence that the terrorists want them destroyed. Target countries are understandably skeptical that making concessions will placate terrorist groups believed to be motivated by these maximalist objectives.

In other words, terrorism doesn’t work, because it makes people less likely to acquiesce to the terrorists’ demands, no matter how limited they might be. The reaction to terrorism has an effect completely opposite to what the terrorists want; people simply don’t believe those limited demands are the actual demands.

This theory explains, with a clarity I have never seen before, why so many people make the bizarre claim that al Qaeda terrorism—or Islamic terrorism in general—is “different”: that while other terrorist groups might have policy objectives, al Qaeda’s primary motivation is to kill us all. This is something we have heard from President Bush again and again—Abrahms has a page of examples in the paper—and is a rhetorical staple in the debate. (You can see a lot of it in the comments to this previous essay.)

In fact, Bin Laden’s policy objectives have been surprisingly consistent. Abrahms lists four; here are six from former CIA analyst Michael Scheuer’s book Imperial Hubris:

  1. End U.S. support of Israel
  2. Force American troops out of the Middle East, particularly Saudi Arabia
  3. End the U.S. occupation of Afghanistan and (subsequently) Iraq
  4. End U.S. support of other countries’ anti-Muslim policies
  5. End U.S. pressure on Arab oil companies to keep prices low
  6. End U.S. support for “illegitimate” (i.e. moderate) Arab governments, like Pakistan

Although Bin Laden has complained that Americans have completely misunderstood the reason behind the 9/11 attacks, correspondent inference theory postulates that he’s not going to convince people. Terrorism, and 9/11 in particular, has such a high correspondence that people use the effects of the attacks to infer the terrorists’ motives. In other words, since Bin Laden caused the death of a couple of thousand people in the 9/11 attacks, people assume that must have been his actual goal, and he’s just giving lip service to what he claims are his goals. Even Bin Laden’s actual objectives are ignored as people focus on the deaths, the destruction and the economic impact.

Perversely, Bush’s misinterpretation of terrorists’ motives actually helps prevent them from achieving their goals.

None of this is meant to either excuse or justify terrorism. In fact, it does the exact opposite, by demonstrating why terrorism doesn’t work as a tool of persuasion and policy change. But we’re more effective at fighting terrorism if we understand that it is a means to an end and not an end in itself; it requires us to understand the true motivations of the terrorists and not just their particular tactics. And the more our own cognitive biases cloud that understanding, the more we mischaracterize the threat and make bad security trade-offs.

This is my 46th essay for Wired.com, based on a paper I blogged about last week (there are a lot of good comments to that blog post).

Posted on July 12, 2007 at 12:59 PMView Comments

Why Terrorism Doesn't Work

This is an interesting paper on the efficacy of terrorism:

This study analyzes the political plights of twenty-eight terrorist groups—the complete list of foreign terrorist organizations (FTOs) as designated by the U.S. Department of State since 2001. The data yield two unexpected findings. First, the groups accomplished their forty-two policy objectives only 7 percent of the time. Second, although the groups achieved certain types of policy objectives more than others, the key variable for terrorist success was a tactical one: target selection. Groups whose attacks on civilian targets outnumbered attacks on military targets systematically failed to achieve their policy objectives, regardless of their nature.

The author believes that correspondent inference theory explains this. Basically, the theory says that people infer the motives of an actor based on the consequences of the action. So people assume that the motives of a terrorist are wanton death and destruction, and not the stated aims of the terrorist group:

The theory posited here is that terrorist groups that target civilians are unable to coerce policy change because terrorism has an extremely high correspondence. Countries believe that their civilian populations are attacked not because the terrorist group is protesting unfavorable external conditions such as territorial occupation or poverty. Rather, target countries infer from the short-term consequences of terrorism—the deaths of innocent citizens, mass fear, loss of confidence in the government to offer protection, economic contraction, and the inevitable erosion of civil liberties—the objectives of the terrorist group. In short, target countries view the negative consequences of terrorist attacks on their societies and political systems as evidence that the terrorists want them destroyed. Target countries are understandably skeptical that making concessions will placate terrorist groups believed to be motivated by these maximalist objectives.

This certainly explains a great deal about the U.S.’s reaction to the 9/11 attacks. Many people—along with our politicians and press—believe that al Qaeda terrorism is different, and they’re just out to kill us all. (In fact, I’m sure I’ll get blog comments along those lines.) The paper examines this belief: where it came from, how it manifested itself, and why it is wrong.

Posted on July 3, 2007 at 6:21 AMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.