Sunday, November 29, 2015

Privacy and Backscatter X-Ray Technology

The New York City Police Department owns an unknown number of high-tech vans that allow their operators to play Superman—at least with regard to his X-ray vision abilities.  An online article in The Atlantic last month describes how NYPD Commissioner Bill Bratton indirectly admitted his organization was using X-ray vans when he refused to discuss the matter at a press conference, citing security concerns.  Superman was a fictional character whose strictly limited flaws were in service of a plot that always ended in the triumph of the unquestionably good over the irrevocably bad.  But real life isn't so simple.  And there are real concerns about the way the NYPD may be using this technology.

First, how does it work?  Offhand, it sounds highly irresponsible for somebody to just shoot X-rays at random passersby.  X-rays are a form of what is called ionizing radiation, meaning that they have enough energy to knock electrons out of atoms to make ions.  Such ions can wreak havoc in the DNA of a biological target, for instance, and lead to cancer and other problems.  That is why medical X-ray systems are highly regulated and only properly trained operators are allowed to use them.

But there is apparently a sort of escape clause for non-medical equipment that uses X-rays.  If it meets a certain technical standard that limits the amount of exposure someone would get from a typical spying operation that lasts a few seconds, then the FDA is not involved and the rules change.  According to numerous sources, the type of X-ray machinery used by the NYPD uses so-called "backscatter" X-ray technology that falls into the low-dose category. 

It's really rather clever.  Conventional X-ray machines use a transmission approach, sending X-rays through the item to be examined and recording what comes out on the other side.  Your dentist uses this type of machine, and the image of your teeth shows up because bone is denser than air or soft tissue and absorbs and scatters more X-rays.  But obviously, for transmission X-rays to work, the rays have to be strong enough to get all the way through the item being examined.

Backscatter X-rays work differently.  Instead of producing a strong beam that illuminates the whole target at once and goes through it, a scanning type of backscatter unit sends a "flying spot" of X-rays sweeping across the target, which could be a person inside his or her clothes, or even a car.  These X-rays don't have to penetrate the target.  Instead, all they have to do is cause a thing called Compton scattering, which is basically what happens when an X-ray encounters an electron and is generous enough to share some of its energy.  The electron takes off with some of the energy and a new X-ray photon appears carrying the energy that's left. 

It is these new lower-energy X-rays that are detected by the backscatter machine, which consequently does not need to use X-rays that are as energetic as those used by conventional transmission machines.  That and the fact that any one point on the target is exposed to X-rays for only a small fraction of the total time of exposure, means that the X-ray dose of a backscatter unit is much smaller than, say, what you'd get from a medical chest X-ray.  Numerous sources confirm that the dose is so small from a surveillance backscatter X-ray device, that you would get something similar by just standing on a street corner for an hour or so and exposing yourself to background radiation.  This comes from sources like cosmic rays and the potassium in construction materials, and everybody gets that every day, twenty-four hours a day.  So despite some concerns on the part of investigative journalists that there are health hazards from backscatter X-ray technology, as long as the systems are working properly and used properly there are much more important things to worry about.  

To my mind, the greater concern about these systems is privacy.  You don't think that research directors of government agencies would go in for public cheesecake photos of themselves, but the Wikipedia article on backscatter X-rays shows such an image of Susan Hallowell, director of the U. S. Transportation Security Administration's research lab.  It is, er, very clear that the image is that of a woman.  We can all be glad that she wasn't a man. 

At this point, we should take a look at the U. S. Constitution's Fourth Amendment, which is short enough to quote in full here:  "The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized."  Updating its 1792-era language to modern terms, it means that no government official can snoop on you unless they swear or affirm that they have a good reason to do so, and the officials can say exactly where they're going to look and what they're going to look for.

I'm not a lawyer, and since the Fourth Amendment was passed it has accumulated various qualifications and exceptions, like a ship picks up barnacles.  But the principle that the writers of that amendment had in mind is still clear.  A person's body, house, papers (which was the only way to record data back then), and "effects" (as in personal effects—what a ten-year-old would call "my stuff") are inviolable against government attempts to mess with them—taking them, looking at them, or anything along those lines.  The only cause strong enough to justify such violation is when the government has a good case to show that something is amiss and can describe what they want to look for and where.  This clearly rules out fishing expeditions, in which an official simply snoops at will and starts investigating a crime when the snooping itself provides evidence.

Right now, the NYPD is in effect saying "Trust us, we're using this X-ray van the right way."  But if citizens can't even know how many vans there are, let alone how they're being used, that is asking for a heck of a lot of trust.

Sources:  The Atlantic's article "The NYPD Is Using Mobile X-Ray Vans to Spy on Unknown Targets" appeared on Oct. 19, 2015 at  I also consulted the websites of firms that make such devices, including American Science and Engineering at and the Tek84 Engineering Group at  I thank my nephew Matt, a graduate student in criminal justice, for bringing this matter up at the Thanksgiving dinner table. 

Monday, November 23, 2015

VW's In A Fix With Their Fix

Back in September, the U. S. Environmental Protection Agency (EPA) accused Volkswagen of cheating with regard to emissions controls of many of its cars that use diesel engines.  VW admitted as much, its CEO resigned, and now the firm faces the problem of fixing all the cars that violate emissions standards.  One way or another, some 11 million cars worldwide are implicated, with about half a million in the U. S. alone.  How did VW get into this fix, and how are they going to dig themselves out?

As new information has emerged on exactly how the cheating was done, it's pretty easy to tell that this was no single-line software tweak by a lone rogue engineer.  According to a Nov. 4 BBC report, someone (probably several someones) designed software to detect when the car was on a test stand designed for EPA checks.  This typically involves running the car while it is on a dynamometer, which uses rollers underneath the wheels to load the engine to simulate actual road conditions.  But in order for the stationary test equipment to be connected to the vehicle, the car is usually sitting still in a laboratory somewhere during the test.  I'm not saying that I know how the software guys did it, but if I were faced with the problem of how to figure out if a test-stand situation like this was going on, I'd look at the built-in accelerometers that every airbag-equipped car has.  If nobody's at the steering wheel and the car isn't going anyplace even if it's in "drive" and the engine's running, chances are it's on a test stand. 

However they did it, when an emission-test situation was detected the car switched into a mode that made it pass the emissions test.  But the price was severely crippled power and lowered engine performance, which however would not typically show up on an emissions test—after all, nobody's actually driving it to tell.  Once the test was over, the software readjusted the engine settings to produce normal power and performance—and as much as forty times more nitrous oxides (NOx) than the EPA allows.  But hey—it passed the test.  That's all that counts, right?

This mode of cheating is why fixing the problem with many diesel models, especially older ones, is not going to be some simple reload-new-software exercise.  If you've gone on a road trip recently and looked around in a truck-stop convenience store, you may have noticed piles of plastic bottles full of something called "diesel exhaust fluid."  Turns out that this stuff is now needed for many tractor-trailer diesel engines in order to meet the EPA's requirements for NOx emissions.  There's machinery on board the truck that squirts the fluid—which contains urea—into the exhaust, and the urea solution vaporizes to form ammonia and carbon dioxide.  The ammonia, in the presence of a catalyst in a thing called a selective catalytic reduction system (SCR), combines with the nasty NOx molecules to form nitrogen and water, which finally leave the exhaust pipe and rejoin Mother Nature, leaving her nearly as pristine as she was before the truck came by. 

It's one thing for truck engineers to see the regulations coming down the pike, and take time to redesign the power plant so as to accommodate another anti-pollution system which requires valves, heaters to keep the urea solution from freezing, pipes, level-monitoring systems, and all the other stuff needed to do the NOx-killing job.  It's quite another thing for VW to be under the gun to retrofit small diesel passenger cars that are maybe four or five years old, with a kit of SCR stuff they were not designed to have.  You'll need someplace to stick the SCR unit in the exhaust line, a way to get a pipe from the SCR to the urea tank, a place to put the urea tank, control lines, etc.  Engineers estimate the cost per vehicle could range up to $1000 or more.  With some cars, it may be cheaper for VW simply to buy them back from the owners and send them to the scrapyard.  Software-only fixes may be possible for some diesel models, but it looks like millions of cars worldwide will need expensive hardware installations to meet current emissions requirements.

VW says its internal investigation into how all this happened is still continuing.  For their sake, I hope they wind it up pretty soon, at least well enough to publish a timeline with names and actions.  But even without such information, it's obvious by now that deception with regard to emissions controls was an established policy.  Maybe the conspiracy—that's not too strong a term at this point—was concealed from upper management, and that's one of the things we need to know.  But even if it was, it's clear that there was a group of engineers inside VW who deliberately set out to cheat the system of pollution controls.  And they got away with it for several years.

It's not often that such a clear-cut case of wrongdoing by engineers makes the headlines.  Far more often, engineers will face a dilemma in which either choice has advantages and disadvantages, both morally and otherwise.  And sometimes engineers make the wrong choice, basing their decisions on incomplete information.  But in most engineering situations, information is always incomplete.  There's always more you'd like to know, but at some point the project must go on, choices must be made, and sometimes they turn out to be wrong ones.

But the VW emissions case is different.  Deception was intended from the start.  I don't know what internal company dynamics brought pressure to bear on engineers to the extent that developing a software evasion of emissions controls seemed like a good idea, but clearly something was wrong with the way ethical principles were stated and handed down. 

Sometimes, companies who do bad things are unrepentant and fight tooth and nail despite being in the wrong.  In such cases, large government fines are sometimes the only thing that will make an impression.  But in VW's case, its CEO resigned, sales are dropping, and there are news stories with graphics that show the famed chrome VW emblem breaking apart.  It's starting to look like the market and news media will do more punishing than the EPA is likely to do.  Whether that's fair or not is almost beside the point.  To survive, VW will have to own up fully, fix the mess it made to the best of its ability, and be a different company from the inside out—from now on.

Sources:  An Associated Press article on the types of fixes needed by VW was published in numerous outlets, including the U. S. News and World Report website on Nov. 19 at  Information on the details of how the cheating software worked was carried by the BBC on Nov. 4 at  I also referred to the Wikipedia article on diesel exhaust fluid.  I last blogged on the VW emissions scandal on Sept. 21, 2015.

Monday, November 16, 2015

Rolling Back Mass Surveillance

Bruce Schneier is a man worth listening to.  In 1993, just as the Internet was gaining speed, he wrote one of the earliest books on applying cryptography to network communications, and has since become a well-known security specialist and author of about a dozen books on Internet security and related matters.  So when someone like Schneier says we're in big trouble and we need to do something fast to keep it from getting worse, we should at least pay attention.

The trouble is mass surveillance.  In his latest book, Data and Goliath, he explains that mass surveillance is the practice of indiscriminately collecting giant data banks of information on people first, and then deciding what you can do with it.  One of the best-known and most controversial examples of this is the practice of the U. S. National Security Agency (NSA) of grabbing telecommunications metadata (basically, who called whom when) covering the entire U. S., which was revealed when Edward Snowden made his stolen NSA files public in 2013.  Advocates of the NSA defend the call database by saying the content of the calls is not monitored, only the fact that they were made.  But Schneier makes short work of that argument in a few well-chosen examples showing that such metadata can easily reveal extremely private facts about a person:  medical conditions or sexual orientation, for example. 

It's not only government overreaching that Schneier is concerned about. Businesses come in for criticism too.  With data storage getting cheaper all the time, many Internet firms and network giants such as Google and Yahoo find that it's easier simply to collect all the data they can on their customers, and then pick through it to see what useful information they can extract—or sell to others.  This happens all the time.  Maybe the most visible evidence of it happens when you go online and look for, say, a barbecue grill at a hardware-store website.  Then, maybe several days later, you will be on a completely different site.  Say a vegetarian friend is coming over and you're looking up how to make vegan stew.  Lo and behold, right next to the vegan recipe, there's an ad for that barbecue grill you were looking at a few days ago.  How did they know?  With "cookies" (bits of data retained by your browser) and behind-the-scenes trading of information about you and your browsing habits.

But Schneier reserves his greatest concern for something that is perhaps hardest to define:  the loss of privacy.  The right to privacy is a vital if poorly defined right whose absence makes normal life almost impossible.  Schneier says, "Privacy is an inherent human right. . . . It is about choice, and having the power to control how you present yourself to the world."  Mass surveillance tramples over the right to privacy and trains millions subtly to alter their ways of living to avoid the pain of secrets revealed.  This way of living was familiar to those whose lives were monitored by totalitarian regimes such as the old East Germany or the Soviet Union.  True, Google isn't going to send a jackbooted corporal to your door if you say something nasty about Sergey Brin, Google's co-founder.  Brin himself was born behind the Iron Curtain, though his family emigrated when he was six, and he probably remembers little or nothing about the USSR.  Nevertheless, Google and other firms that collect massive amounts of private data from their customers have set up a situation in which the privacy rights of millions, even billions, depend solely on the good intentions of a few powerful decision-makers in private companies. 

So what do we do about this?  Schneier has lots of suggestions, and points to Europe as a place where privacy is more respected in law and custom.  Changing laws is a necessary first step.  Whenever anyone moves to restrict the mass-surveillance habits of government entities such as the NSA or the Federal Bureau of Investigation, their defenders threaten us with a terrorist apocalypse, saying if we don't give up this or that privacy right, we'll tie the government's hands and be helpless before terrorist assaults.  Schneier spends a lot of time taking apart this argument, to my mind pretty convincingly.  For one thing, mass-surveillance data has not proved that useful in uncovering terrorist plots, compared to old-fashioned detective work focused intensely on a few known troublemakers. In general, government should abandon most mass-surveillance practices in favor of concentrating on specific investigations, with permission granted by courts whose workings are made public to the extent possible.

As for massive snooping by private enterprises, Schneier thinks regulations are the best option.  These regulations would impose a kind of "opt-in" system.  Currently, if you have a privacy-related choice at all in dealing with Internet firms, you have to go to a lot of trouble to make them respect your privacy, if they will allow such a thing at all.  Under Schneier's proposed policy, companies could not take away your rights to your data without your explicit permission, and the choice would be explained clearly enough so that you wouldn't need to have your techno-lawyer read the fine print to understand what's going on. 

Neither Schneier nor I are political scientists, so it's hard to say how we would get from the current parlous situation to one in which online privacy is respected, and nobody can snoop on you unless they go to a lot of trouble and get special permission to do it.  But he's told us what the problem is, and now it's up to us to do something about it.

Sources:  Bruce Schneier's book Data and Goliath:  The Hidden Battles to Collect Your Data and Control Your World was published by W. W. Norton in 2015.  The quotation from it above is from p. 126.  I also referred to Wikipedia articles on Edward Snowden, MAINWAY (the NSA call databse), and Sergey Brin.

Monday, November 09, 2015

Did Exxon Mobil Lie About Climate Change?

The energy giant Exxon Mobil is being investigated by New York State's attorney general, according to a report last week in the New York Times.  The issue appears to be whether Exxon properly stated the risks of climate change to its future business in light of its own internal scientific climate research.  Critics of the company say it has engaged in deception similar to what tobacco companies did in the 1960s and 1970s, when cigarette makers funded research that cast doubt on the health dangers of tobacco use even as they knew the grim truth and concealed it.  For its part, Exxon's spokesman Kenneth P. Cohen said, "We unequivocally reject the allegations that Exxon Mobil has suppressed climate change research." 

Under a law called the Martin Act, the New York attorney general is charged with the investigation of financial fraud, and can issue subpoenas for records and documents relating to such an investigation.  Exxon got a subpoena along these lines last week, and is in the process of responding to it. 

Let's step back a moment and examine the question of how this case relates to the well-known practices of tobacco companies that attacked the credibility of research that showed smoking and chewing their products was hazardous to one's health.

The history of how Big Tobacco muddied the research waters is pretty clear.  After the tobacco firms fought what became a rear-guard action against the mounting evidence that smoking kills, both state and U. S. federal attorneys general sued large companies such as R. J. Reynolds beginning in the 1990s, claiming that they deceived consumers about the dangers of smoking even as the company's own internal research revealed the hazards involved.  These successful suits cost the companies billions of dollars in fines and continuing payments into state-controlled public-health funds. 

One of my high-school teachers loved questions that began, "Compare and contrast. . ." so let's do that here.  What are the comparisons and the contrasts between what Big Tobacco did, and what Big Oil is supposedly doing?

First, the comparison for similarities.  Exxon may have funded some researchers at times who opposed the general scientific consensus about climate change.  This consensus has itself been somewhat of a moving target as more data, more sophisticated computer models, and a better understanding of climatology in general have contributed to knowledge of the problem.   So for Exxon to be liable in the way that, say, R. J. Reynolds was liable, someone would have to show that (a) Exxon was publicly saying climate change isn't going to bother us, and (b) Exxon privately knew pretty much the opposite. 

There is also the question of harm.  It's pretty easy for a lawyer to argue that his late client died from smoking, which the client might have ceased and desisted from doing had he not been lied to by the maker of his cigarettes.  If some of the more dire forecasts of the climate-change prophets come to pass, we will also have widespread death and destruction from it too.  And to the extent that companies like Exxon were responsible for it, they could conceivably be held liable in some way.

Now for the contrasts.  Apparently the worst thing that the New York attorney general thinks Exxon has done is not murder or criminal negligence, but financial fraud.  Fraud generally involves the premeditated intent to trick or deceive someone to your own advantage.  The idea here seems to be that if (and that is a big "if") laws are passed or other factors intervene to make it harder for Exxon to profit from fossil fuels because of climate change, and Exxon knew this was likely to happen, and Exxon told its investors otherwise, then they have tricked their investors. 

Whatever you want to call this alleged action, it's a far cry from what blatant deceivers like Bernie Madoff did.  Madoff, you may recall, ran a Ponzi scheme and kept one set of books for public consumption and another set for his secret fraudulent operations.  While some European countries have begun to restrict fossil-fuel use in various ways—high fossil-fuel taxes, for example—their reasons for doing so often go beyond the threat of climate change.  And in the U. S., to the frustration of environmentalists, very few meaningful climate-change-inspired restrictions have been placed so far on the consumption of oil, gas, and coal.  This may change in the future, but it's hard to sue somebody for something that hasn't happened yet.  Oil prices have recently tanked (so to speak), but the reasons have little or nothing to do with climate-change laws and a lot more to do with higher domestic production and international politics. 

Another question is whether an engineering-intensive firm that operates legally to fulfill a widespread public need, as energy companies do, can be held liable for the free consumption decisions of millions of its customers.  Again, we come to the question of who has been harmed.  While lying is bad, if we find out that Exxon made some forecasts of future climate change that turn out to be wrong, that's not exactly the same as lying.  Overall, this investigation seems to be based on speculation about future harms more than it is a realistic assessment of how investors have been harmed up to now.  And such a thing will be hard to put across to a reasonable jury, assuming the case gets that far.

Of course, this may be the beginnings of what some might view as a government shakedown.  Rather than face the prospect of spending years or decades in court, Exxon may choose to settle out of court by paying fines or changing its way of business to make the New York attorney general happy.  Such proceedings always smack of blackmail to a greater or lesser degree, although sometimes they are the least bad alternative if a genuine wrong has occurred.

But to find out if that is the case, we'll just have to wait.  Wait to see what the attorney general of New York does next; wait to see if states and countries pass much more restrictive legislation inspired by climate change; and wait to see how much hotter it gets.  It may be a long wait for any or all of these things, so stay tuned.

Sources:  The New York Times article "Exxon Mobil Investigated for Possible Climate Change Lies by New York Attorney General" appeared on Nov. 6, 2015 at  I also referred to the Wikipedia article "Tobacco politics."  I blogged on a related matter pertaining to climate change and university-funded research in "A Chunk of (Climate) Change", posted on Mar. 2, 2015.

Monday, November 02, 2015

Arms Control for Cyberwarfare Weapons

Say you're a high-tech software security firm in the U. S. that sells a spyware application that lets your corporate customers monitor all the encrypted traffic going through their servers.  A benign reason that a customer of yours wants to buy your software is to catch encrypted malware that might otherwise mess up the customer's system operations.  But that's not the only way your software product could be used.

Say a repressive government wants to ferret out members of an opposition group who are trying to organize a grass-roots protest campaign.  The protesters use encrypted Internet communications to do so, and using the software your company makes, the repressive government finds out who the protest ringleaders are, rounds them up, and decapitates them all at sunrise.  Should you have sold your software to that government?

Quandaries like these are at the heart of a dispute between the U. S. Department of Commerce and Silicon Valley computer-security-software firms.   According to a recent New York Times report, back in May the Commerce Department proposed new export restrictions on a wide variety of security software.  Following howls of protest by software firms, the proposal was shelved, but the Obama administration has continued to prosecute isolated cases of software showing up in Iran or Syria, which are the only two countries that are currently subject to export bans specifically targeted at surveillance technology. 

Unfortunately, such bans are not that difficult to evade, given enough resources.  Modern-day gun runners (code runners?) can have the stuff sent to dummy firms in non-banned countries, and then turn around and send it from there through a few more countries to its true banned destination.  According to the report, that is exactly what a couple of alleged smugglers from the United Arab Emirates did to get products from computer-security firm Blue Coat Systems to Syria, where the use of that software by the Syrian government was detected and published by a Canadian firm, which told the U. S. Commerce Department about it. 

A number of my recent blogs have dealt with aspects of cyberwarfare, and the increasing arms trade in software such as Blue Coat's products is one more sign that warfare and its associated activities such as spying are moving rapidly into the cyber arena.  Trade restrictions on conventional arms are a familiar part of the diplomatic landscape, but deciding which physical weapons to keep to ourselves is easier than dealing with certain kinds of security software.  A nuclear weapon is good for only one thing, for instance, but the type of security system that companies like Blue Coat sell can be used for either good or bad reasons, as my example shows. 

The current compromise restricts direct sales of such software to Iran and Syria, but as we've seen, it's pretty easy to evade even those restrictions.  The fact of the matter is that small countries can buy pretty much anything they want, given enough time and determination, and larger countries such as China have enough resources to develop their own spyware.

So it looks like the most realistic position these days is to realize that one way or another, bad governments (whatever your criterion of "bad" is) will probably be able to spy on Internet traffic and do other things online that we would wish they couldn't do.  In such an environment, what are the prospects for free speech, freedom of association, and other democratic activities that presume citizens are not under the constant baleful glare of Big Brother, whose cybernetic eye never closes?

A little historical perspective is in order here.  Things like the U. S. Constitution's Bill of Rights are fairly recent innovations.  For most of recorded history, nobody except maybe a few favored upper-class rich people had anything resembling what we consider to be legal rights.  Even in peacetime, if you were a peasant or a slave, and the king or some rich guy came along and took away your donkey, your land, or even your life, there wasn't much you could do about it.  In the West, the rise of Enlightenment ideas about universal rights took centuries to develop, and it was by no means clear when the founders of the United States wrote them into the Constitution, that the experiment would work.  But work it did, and recognition of these rights achieved a high point in 1948 when the United Nations adopted its Universal Declaration of Human Rights, which includes the right to freedoms such as privacy and speech.

As the old saying goes, the price of liberty is eternal vigilance.  And lately, even in the U. S., we have seen actions at the highest levels of government that smack of the suppression of free speech.  I have not read The Silencing:  How the Left Is Killing Free Speech, a book by conservative commentator Kirsten Powers, but reports of the book cite incidents in which the Obama White House banned conservative Fox News correspondents from certain press briefings.  These are isolated incidents, but they indicate that at least in some circles, the fundamental right of free speech has lost some of its appeal when other urgent issues come to the fore.

It's a far cry from disinviting reporters to spying on everyone's Internet traffic, but the idea is the same:  control of what people are saying to other people.  The Silicon Valley contingent has a lot to say about open-source software and the idea that "information wants to be free."  But the fact that repressive governments can use computer-security products for suppression of freedom is a grim reminder that engineers have to use their imaginations when they make new tools.  Imagining how you, a presumably nice guy or gal, would use your newly invented computer-security product is one thing.  But you should also try the experiment of thinking about how some evil genius could use your product—and then maybe try to do something that would make it harder for the bad guys to succeed.

Sources:  The New York Times report by James Risen, "Battle Heats Up over Exports of Surveillance Technology" appeared on Oct. 31, 2015 online at  I also referred to a discussion of Kirsten Powers' book at RealClearPolitics,, and the U. N.'s Universal Declaration of Human Rights at