April 15, 2008

by Bruce Schneier
Founder and CTO
BT Counterpane

A free monthly newsletter providing summaries, analyses, insights, and commentaries on security: computer and otherwise.

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In this issue:

Third Annual Movie-Plot Threat Contest

For this contest, the goal is to create fear. Not just any fear, but a fear that you can alleviate through the sale of your new product idea. There are lots of risks out there, some of them serious, some of them so unlikely that we shouldn't worry about them, and some of them completely made up. And there are lots of products out there that provide security against those risks.

Your job is to invent one. First, find a risk or create one. It can be a terrorism risk, a criminal risk, a natural-disaster risk, a common household risk -- whatever. The weirder the better. Then, create a product that everyone simply *has to* buy to protect him- or herself from that risk. And finally, write a catalog ad for that product.

Here's an example, pulled from page 25 of the Late Spring 2008 Skymall catalog I'm reading on my airplane as I write this:

"A Turtle is Safe in Water, A Child is Not! Even with the most vigilant supervision a child can disappear in seconds and not be missed until it's too late. Our new wireless pool safety alarm system is a must for pool owners and parents of young children. The Turtle Wristband locks on the child's wrist (a special key is required to remove it) and instantly detects immersion in water and sounds a shrill alarm at the Base Station located in the house or within 100 feet of the pool, spa, or backyard pond. Keep extra wristbands on hand for guests or to protect the family dog."

Entries are limited to 150 words -- the example above had 97 words -- because fear doesn't require a whole lot of explaining. Tell us why we should be afraid, and why we should buy your product.

Entries will be judged on creativity, originality, persuasiveness, and plausibility. It's okay if the product you invent doesn't actually exist, but this isn't a science fiction contest.

Portable salmonella detectors for salad bars. Acoustical devices that estimate tiger proximity based on roar strength. GPS-enabled wallets for use when you've been pickpocketed. Wrist cuffs that emit fake DNA to fool DNA detectors. The Quantum Sleeper. Fear offers endless business opportunities. Good luck.

Entries due by May 1. Submit them as entries to the blog post. And even if you don't want to enter, go read some of the submissions. You people are frighteningly creative.

Blog post:

The First Movie-Plot Threat Contest rules:
And winners: The Second Movie-Plot Threat Contest rules:
And winners:

The Security Mindset

Uncle Milton Industries has been selling ant farms to children since 1956. Some years ago, I remember opening one up with a friend. There were no actual ants included in the box. Instead, there was a card that you filled in with your address, and the company would mail you some ants. My friend expressed surprise that you could get ants sent to you in the mail.

I replied: "What's really interesting is that these people will send a tube of live ants to anyone you tell them to."

Security requires a particular mindset. Security professionals -- at least the good ones -- see the world differently. They can't walk into a store without noticing how they might shoplift. They can't use a computer without wondering about the security vulnerabilities. They can't vote without trying to figure out how to vote twice. They just can't help it.

SmartWater is a liquid with a unique identifier linked to a particular owner. "The idea is for me to paint this stuff on my valuables as proof of ownership," I wrote when I first learned about the idea. "I think a better idea would be for me to paint it on your valuables, and then call the police."

Really, we can't help it.

This kind of thinking is not natural for most people. It's not natural for engineers. Good engineering involves thinking about how things can be made to work; the security mindset involves thinking about how things can be made to fail. It involves thinking like an attacker, an adversary or a criminal. You don't have to exploit the vulnerabilities you find, but if you don't see the world that way, you'll never notice most security problems.

I've often speculated about how much of this is innate, and how much is teachable. In general, I think it's a particular way of looking at the world, and that it's far easier to teach someone domain expertise -- cryptography or software security or safecracking or document forgery -- than it is to teach someone a security mindset.

Which is why CSE 484, an undergraduate computer-security course taught this quarter at the University of Washington, is so interesting to watch. Professor Tadayoshi Kohno is trying to teach a security mindset.

You can see the results in the blog the students are keeping. They're encouraged to post security reviews about random things: smart pill boxes, Quiet Care Elder Care monitors, Apple's Time Capsule, GM's OnStar, traffic lights, safe deposit boxes, and dorm room security.

One recent one is about an automobile dealership. The poster described how she was able to retrieve her car after service just by giving the attendant her last name. Now any normal car owner would be happy about how easy it was to get her car back, but someone with a security mindset immediately thinks: "Can I really get a car just by knowing the last name of someone whose car is being serviced?"

The rest of the blog post speculates on how someone could steal a car by exploiting this security vulnerability, and whether it makes sense for the dealership to have this lax security. You can quibble with the analysis -- I'm curious about the liability that the dealership has, and whether their insurance would cover any losses -- but that's all domain expertise. The important point is to notice, and then question, the security in the first place.

The lack of a security mindset explains a lot of bad security out there: voting machines, electronic payment cards, medical devices, ID cards, internet protocols. The designers are so busy making these systems work that they don't stop to notice how they might fail or be made to fail, and then how those failures might be exploited. Teaching designers a security mindset will go a long way toward making future technological systems more secure.

That part's obvious, but I think the security mindset is beneficial in many more ways. If people can learn how to think outside their narrow focus and see a bigger picture, whether in technology or politics or their everyday lives, they'll be more sophisticated consumers, more skeptical citizens, less gullible people.

If more people had a security mindset, services that compromise privacy wouldn't have such a sizable market share -- and Facebook would be totally different. Laptops wouldn't be lost with millions of unencrypted Social Security numbers on them, and we'd all learn a lot fewer security lessons the hard way. The power grid would be more secure. Identity theft would go way down. Medical records would be more private. If people had the security mindset, they wouldn't have tried to look at Britney Spears' medical records, since they would have realized that they would be caught.

There's nothing magical about this particular university class; anyone can exercise his security mindset simply by trying to look at the world from an attacker's perspective. If I wanted to evade this particular security device, how would I do it? Could I follow the letter of this law but get around the spirit? If the person who wrote this advertisement, essay, article or television documentary were unscrupulous, what could he have done? And then, how can I protect myself from these attacks?

The security mindset is a valuable skill that everyone can benefit from, regardless of career path.


CSE484 blog:
Britney Spears' medical records:

This essay originally appeared on


Camera that sees under clothes:
If this is real, it seems much less invasive than backscatter X ray.

Four items from Montana. The difficulty of implementing REAL-ID in areas so remote they don't have a permanent DMV.
The difficulty of implementing airport security at airports so remote they average only two passengers per flight.
This is the best: Brian Schweitzer, Montana's governor, speaking about his opposition to REAL ID.
More on Montana and REAL-ID.

New research on how the brain estimates risk.

Bomb squad defuses turnip. Props to the writer who came up with the first sentence of the story: "A raw turnip was at the root of a bomb scare that last for hours at a law office."
Comment on my blog from someone claiming to be the turnip mailer:
Another dispatch from the continuing slide towards thoughtcrime: a suggestion from the UK of putting primary-school children in a DNA database "exhibit behaviour indicating they may become criminals in later life." Thankfully, the article contains some reasonable reactions to this proposal.

This is another excellent series of posts on threat modeling at Microsoft, this time from Adam Shostack.
First post:
Entire series as Word document:
I already linked to this series by Larry Osterman.

Despite "heartbeat sensors, CO2 probes to detect exhaled breath and 'passive millimetre wave' scanners which can 'see' through vehicles," it's easy to sneak into the UK from Calais due to inadequate fencing. Remember: security is only as strong as the weakest link.

Wacky airplane security idea of the month: Force everyone to wear a bracelet that, when remotely activated, gives the person a debilitating shock. No, really. A company is trying to commercialize this idea. The mind boggles.
This sort of credit card fraud is nothing new, but it's rare to see statistics of actual fraud.
My guess is that it's an inside job.

MC Frontalot raps about encryption:

Really good blog post on the future potential of quantum computing and its effects on cryptography.
A quantum computer scientist responds:

If you're fearful, you think you're more at risk than if you're angry:

Build your own paper Enigma machine:
An Enigma on an old Atari 2600 video game:
Excellent and well-written article on the Enigma by the NSA:

At the DISI conference last December, Martin Hellman gave a lecture on the invention of public-key cryptography.

This article from The Wall Street Journal outlines how the NSA is increasingly engaging in domestic surveillance, data collection, and data mining. The result is essentially the same as Total Information Awareness.
Barry Steinhardt of the ACLU comments.
More commentary:

Hypnotist thief in Italy. This is weird:
The U.S. has a new cyber-security czar, Rod A. Beckstrom, who has no cyber-security experience.
Malware targeted against pro-Tibet groups. Seems to be the Chinese government, although -- of course -- there's really no way to prove this.
Blog entry URL:

Science fiction writers offer homeland security advice. It's embarrassing.
Good list of common corporate security pitfalls:
The N-DEx National Intelligence System: more data collection on everyone.
A church pastor is an identity thief.
The more trusted a thief is, the harder he is to catch.

Got an idea how to build a liquid bottle scanner? The TSA wants to give you money.
The Quantum Sleeper Unit: fearmongering and security theater at its finest.

The Chaos Computer Club published the fingerprint of Germany's interior minister, Wolfgang Schauble. This is 1) a good demonstration that a fingerprint is not a secret, and 2) a great political hack. Schauble is a strong supporter of collecting biometric data on everyone as an antiterrorist measure. Because, um, because it sounds like a good idea.
The fingerprint itself, ready to print out:
English-language guide to lifting and using fingerprints.
Me on biometrics from ten years ago:

The U.S. is outsourcing the manufacture of its RFID passports to some questionable companies. This is a great illustration of the maxim "security trade-offs are often made for non-security reasons." I can imagine the manager in charge: "Yes, it's insecure. But think of the savings!"
Australia may outlaw laser pointers, because they were used against planes last month. I'm sure criminals also used cars in Australia last week. Will the country ban them next? On the other hand, I'm sick and tired of laser pointers myself. But the cats of Australia will be terribly disappointed.
An eerily prescient article from The Atlantic in 1967 about the future of data privacy and security. It presents all of the basic arguments for strict controls on data collection of personal information, and it's remarkably accurate in its predictions of the future development and importance of computers as well as all of all of the ways the government would abuse them. Well worth reading.
This labyrinth security lock is an April Fool's joke, but I want one.

We finally have some actual information about the "liquid bomb" that was planned by that London group arrested in 2006: "The court heard the bombers intended to use hydrogen peroxide and mix it with a product called Tang, used in soft drinks, to turn it into an explosive. They intended to carry it on board disguised as 500ml bottles of Oasis or Lucozade by using food dye to recreate the drinks' distinctive colour. The detonator would have been disguised as AA 1.5 batteries. The contents of the batteries would have been removed and an electric element such as a light bulb or wiring would have been inserted. A disposable camera would have provided a power source."
Much commentary on my blog about the feasibility of this:

The KeeLoq keyless entry system is used by Chrysler, Daewoo, Fiat, General Motors, Honda, Toyota, Lexus, Volvo, Volkswagen, Jaguar, and probably others. It's broken.

This is a weird story. A burglar gives himself cover by posting a hoax Craigslist ad saying that the owner of a home had to leave suddenly, and his belongings were free for the taking. He steals stuff, as do other people who believe the ad.

Would-be bomber caught at Orlando Airport due to behavioral profiling. My comments are here:

Data from San Francisco demonstrating the ineffectiveness of security cameras. This quote is instructive: "Mayor Gavin Newsom called the report 'conclusively inconclusive' on Thursday but said he still wants to install more cameras around the city because they make residents feel safer." That's right: the cameras aren't about security, they're about security theater. More comments on the general issue here.
NSA has released its version of Linux. So, do you trust it?
NSA's guide to securing Linux:

More colleges offer degrees in homeland security:

Tracking vehicles through tire-pressure monitors: just another example of our surveillance future.

This is a great essay by a mom who let her 9-year-old son ride the New York City subway alone, and the whole discussion is illustrative how we overestimate threats against children:

There's a plan to create a nationwide emergency alert system using text messages. The real question is whether the benefits outweigh the risks. I could certainly imagine scenarios where getting short text messages out to everyone in a particular geographic area is a good thing, but I can also imagine the hacking possibilities. And once this system is developed for emergency use, can a bulk SMS business be far behind?

In this article analyzing a security failure resulting in live nuclear warheads being flown over the U.S., there's an interesting commentary on people and security produres: "'Let's not forget that the existing rules were pretty tight,' says Hans Kristensen, director of the Nuclear Information Project for the Federation of American Scientists. 'Much of what went wrong occurred because people didn't follow these tight rules. You can have all sorts of rules and regulations, but they still won't do any good if the people don't follow them.' Procedures are a tough balancing act. If they're too lax, there will be security problems. If they're too tight, people will get around them and there will be security problems.,15240,165396,00.html

Pentagon may issue pocket lie detectors to American soldiers in Afghanistan, even though they don't work.

Good article on the difficulty of keeping drugs out of prisons. Lots of ways to evade security, including making use of corrupt guards.

I previously wrote about the UK's Regulation of Investigatory Powers Act (RIPA), which was sold as a means to tackle terrorism, and other serious crimes, being used against animal rights protestors. The latest news from the UK is that a local council has used provisions of the act to put a couple and their children under surveillance, for "suspected fraudulent school place applications." This kind of thing happens again and again. When campaigning for a law's passage, the authorities invoke the most heinous of criminals -- terrorists, kidnappers, drug dealers, child pornographers -- but after the law is passed, they start using it in more mundane situations.

The Feeling and Reality of Security

Security is both a feeling and a reality, and they're different. You can feel secure even though you're not, and you can be secure even though you don't feel it. There are two different concepts mapped onto the same word -- the English language isn't working very well for us here -- and it can be hard to know which one we're talking about when we use the word.

There is considerable value in separating out the two concepts: in explaining how the two are different, and understanding when we're referring to one and when the other. There is value as well in recognizing when the two converge, understanding why they diverge, and knowing how they can be made to converge again.

Some fundamentals first. Viewed from the perspective of economics, security is a trade-off. There's no such thing as absolute security, and any security you get has some cost: in money, in convenience, in capabilities, in insecurities somewhere else, whatever. Every time someone makes a decision about security -- computer security, community security, national security -- he makes a trade-off.

People make these trade-offs as individuals. We all get to decide, individually, if the expense and inconvenience of having a home burglar alarm is worth the security. We all get to decide if wearing a bulletproof vest is worth the cost and tacky appearance. We all get to decide if we're getting our money's worth from the billions of dollars we're spending combating terrorism, and if invading Iraq was the best use of our counterterrorism resources. We might not have the power to *implement* our opinion, but we get to decide if we think it's worth it.

Now we may or may not have the expertise to make those trade-offs intelligently, but we make them anyway. All of us. People have a natural intuition about security trade-offs, and we make them, large and small, dozens of times throughout the day. We can't help it: It's part of being alive.

Imagine a rabbit, sitting in a field eating grass. And he sees a fox. He's going to make a security trade-off: Should he stay or should he flee? Over time, the rabbits that are good at making that trade-off will tend to reproduce, while the rabbits that are bad at it will tend to get eaten or starve.

So, as a successful species on the planet, you'd expect that human beings would be really good at making security trade-offs. Yet, at the same time, we can be hopelessly bad at it. We spend more money on terrorism than the data warrants. We fear flying and choose to drive instead. Why?

The short answer is that people make most trade-offs based on the *feeling* of security and not the reality.

I've written a lot about how people get security trade-offs wrong, and the cognitive biases that cause us to make mistakes. Humans have developed these biases because they make evolutionary sense. And most of the time, they work.

Most of the time -- and this is important -- our feeling of security matches the reality of security. Certainly, this is true of prehistory. Modern times are harder. Blame technology, blame the media, blame whatever. Our brains are much better optimized for the security trade-offs endemic to living in small family groups in the East African highlands in 100,000 B.C. than to those endemic to living in 2008 New York.

If we make security trade-offs based on the feeling of security rather than the reality, we choose security that makes us *feel* more secure over security that actually makes us more secure. And that's what governments, companies, family members and everyone else provide. Of course, there are two ways to make people feel more secure. The first is to make people actually more secure and hope they notice. The second is to make people feel more secure without making them actually more secure, and hope they don't notice.

The key here is whether we notice. The feeling and reality of security tend to converge when we take notice, and diverge when we don't. People notice when 1) there are enough positive and negative examples to draw a conclusion, and 2) there isn't too much emotion clouding the issue.

Both elements are important. If someone tries to convince us to spend money on a new type of home burglar alarm, we as society will know pretty quickly if he's got a clever security device or if he's a charlatan; we can monitor crime rates. But if that same person advocates a new national antiterrorism system, and there weren't any terrorist attacks before it was implemented, and there weren't any after it was implemented, how do we know if his system was effective?

People are more likely to realistically assess these incidents if they don't contradict preconceived notions about how the world works. For example: It's obvious that a wall keeps people out, so arguing against building a wall across America's southern border to keep illegal immigrants out is harder to do.

The other thing that matters is agenda. There are lots of people, politicians, companies and so on who deliberately try to manipulate your feeling of security for their own gain. They try to cause fear. They invent threats. They take minor threats and make them major. And when they talk about rare risks with only a few incidents to base an assessment on -- terrorism is the big example here -- they are more likely to succeed.

Unfortunately, there's no obvious antidote. Information is important. We can't understand security unless we understand it. But that's not enough: Few of us really understand cancer, yet we regularly make security decisions based on its risk. What we do is accept that there are experts who understand the risks of cancer, and trust them to make the security trade-offs for us.

There are some complex feedback loops going on here, between emotion and reason, between reality and our knowledge of it, between feeling and familiarity, and between the understanding of how we reason and feel about security and our analyses and feelings. We're never going to stop making security trade-offs based on the feeling of security, and we're never going to completely prevent those with specific agendas from trying to take care of us. But the more we know, the better trade-offs we'll make.

Getting security trade-offs wrong:

Cognitive biases that affect security:

"In Praise of Security Theater"

The security lemon's market:

Airline security and agenda:

This essay originally appeared in

Web Entrapment

Frightening sting operation by the FBI. They posted links to supposed child porn videos on boards frequented by those types, and obtained search warrants based on access attempts.

This seems like incredibly flimsy evidence. Someone could post the link as an embedded image, or send out e-mail with the link embedded, and completely mess with the FBI's data -- and the poor innocents' lives. Such are the problems when the mere clicking on a link is justification for a warrant.

Schneier/BT Counterpane News

Interviews with Schneier:

Schneier is speaking at the Hack-in-the-Box Security Conference in Dubai on April 16th:

Schneier is speaking at the IT Security and Society Conference in Eindhoven, Netherlands, on April 21:

Schneier is speaking at InfoSecurity Europe in London on April 23:

Schneier is speaking at the Universitat Autonoma de Barcelona in Barcelona, Spain, on April 24:

Speeding Tickets and Agenda

If you ever need an example to demonstrate that security is a function of agenda, use this story about speed cameras. Cities that have installed speed cameras are discovering motorists are driving slower, which is decreasing revenues from fines. So they're turning the cameras off.

Fines should never be considered part of a revenue stream: it gives the police a whole new incentive -- and one we don't want them to have.

Seat Belts and Compensating Behavior

There is a theory that people have an inherent risk thermostat that seeks out an optimal level of risk. When something becomes inherently safer -- a law is passed requiring motorcycle riders to wear helmets, for example -- people compensate by riding more recklessly. I first read this theory in a 1999 paper by John Adams at the University of Reading, although it seems to have originated with Sam Peltzman.

In any case, a new paper presents data that contradicts that thesis: "This paper investigates the effects of mandatory seat belt laws on driver behavior and traffic fatalities. Using a unique panel data set on seat belt usage in all U.S. jurisdictions, we analyze how such laws, by influencing seat belt use, affect the incidence of traffic fatalities. Allowing for the endogeneity of seat belt usage, we find that such usage decreases overall traffic fatalities. The magnitude of this effect, however, is significantly smaller than the estimate used by the National Highway Traffic Safety Administration. In addition, we do not find significant support for the compensating-behavior theory, which suggests that seat belt use also has an indirect adverse effect on fatalities by encouraging careless driving. Finally, we identify factors, especially the type of enforcement used, that make seat belt laws more effective in increasing seat belt usage."

John Adams:

Internet Censorship

A review of Access Denied, edited by Ronald Deibert, John Palfrey, Rafal Rohozinski and Jonathan Zittrain, MIT Press: 2008.

In 1993, Internet pioneer John Gilmore said "the net interprets censorship as damage and routes around it", and we believed him. In 1996, cyberlibertarian John Perry Barlow issued his 'Declaration of the Independence of Cyberspace' at the World Economic Forum at Davos, Switzerland, and online. He told governments: "You have no moral right to rule us, nor do you possess any methods of enforcement that we have true reason to fear."

At the time, many shared Barlow's sentiments. The Internet empowered people. It gave them access to information and couldn't be stopped, blocked or filtered. Give someone access to the Internet, and they have access to everything. Governments that relied on censorship to control their citizens were doomed.

Today, things are very different. Internet censorship is flourishing. Organizations selectively block employees' access to the Internet. At least 26 countries -- mainly in the Middle East, North Africa, Asia, the Pacific and the former Soviet Union -- selectively block their citizens' Internet access. Even more countries legislate to control what can and cannot be said, downloaded or linked to. "You have no sovereignty where we gather," said Barlow. Oh yes we do, the governments of the world have replied.

Access Denied is a survey of the practice of Internet filtering, and a sourcebook of details about the countries that engage in the practice. It is written by researchers of the OpenNet Initiative (ONI), an organization that is dedicated to documenting global Internet filtering around the world.

The first half of the book comprises essays written by ONI researchers on the politics, practice, technology, legality and social effects of Internet filtering. There are three basic rationales for Internet censorship: politics and power; social norms, morals and religion; and security concerns.

Some countries, such as India, filter only a few sites; others, such as Iran, extensively filter the Internet. Saudi Arabia tries to block all pornography (social norms and morals). Syria blocks everything from the Israeli domain ".il" (politics and power). Some countries filter only at certain times. During the 2006 elections in Belarus, for example, the website of the main opposition candidate disappeared from the Internet.

The effectiveness of Internet filtering is mixed; it depends on the tools used and the granularity of filtering. It is much easier to block particular URLs or entire domains than it is to block information on a particular topic. Some countries block specific sites or URLs based on some predefined list but new URLs with similar content appear all the time. Other countries -- notably China -- try to filter on the basis of keywords in the actual web pages. A halfway measure is to filter on the basis of URL keywords: names of dissidents or political parties, or sexual words.

Much of the technology has other applications. Software for filtering is a legitimate product category, purchased by schools to limit access by children to objectionable material and by corporations trying to prevent their employees from being distracted at work. One chapter discusses the ethical implications of companies selling products, services and technologies that enable Internet censorship.

Some censorship is legal, not technical. Countries have laws against publishing certain content, registration requirements that prevent anonymous Internet use, liability laws that force Internet service providers to filter themselves, or surveillance. Egypt does not engage in technical Internet filtering; instead, its laws discourage the publishing and reading of certain content -- it has even jailed people for their online activities.

The second half of Access Denied consists of detailed descriptions of Internet use, regulations and censorship in eight regions of the world, and in each of 40 different countries. The ONI found evidence of censorship in 26 of those 40. For the other 14 countries, it summarizes the legal and regulatory framework surrounding Internet use, and tests the results that indicated no censorship. This leads to 200 pages of rather dry reading, but it is vitally important to have this information well-documented and easily accessible. The book's data are from 2006, but the authors promise frequent updates on the ONI website.

No set of Internet censorship measures is perfect. It is often easy to find the same information on uncensored URLs, and relatively easy to get around the filtering mechanisms and to view prohibited web pages if you know what you're doing. But most people don't have the computer skills to bypass controls, and in a country where doing so is punishable by jail -- or worse -- few take the risk. So even porous and ineffective attempts at censorship can become very effective socially and politically.

In 1996, Barlow said: "You are trying to ward off the virus of liberty by erecting guard posts at the frontiers of cyberspace. These may keep out the contagion for some time, but they will not work in a world that will soon be blanketed in bit-bearing media."

Brave words, but premature. Certainly, there is much more information available to many more people today than there was in 1996. But the Internet is made up of physical computers and connections that exist within national boundaries. Today's Internet still has borders and, increasingly, countries want to control what passes through them. In documenting this control, the ONI has performed an invaluable service.

OpenNet Initiative:

This was originally published in Nature:

Comments from Readers

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CRYPTO-GRAM is a free monthly newsletter providing summaries, analyses, insights, and commentaries on security: computer and otherwise. You can subscribe, unsubscribe, or change your address on the Web at <>. Back issues are also available at that URL.

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CRYPTO-GRAM is written by Bruce Schneier. Schneier is the author of the best sellers "Beyond Fear," "Secrets and Lies," and "Applied Cryptography," and an inventor of the Blowfish and Twofish algorithms. He is founder and CTO of BT Counterpane, and is a member of the Board of Directors of the Electronic Privacy Information Center (EPIC). He is a frequent writer and lecturer on security topics. See <>.

BT Counterpane is the world's leading protector of networked information - the inventor of outsourced security monitoring and the foremost authority on effective mitigation of emerging IT threats. BT Counterpane protects networks for Fortune 1000 companies and governments world-wide. See <>.

Crypto-Gram is a personal newsletter. Opinions expressed are not necessarily those of BT or BT Counterpane.

Copyright (c) 2008 by Bruce Schneier.

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