Essays in the Category "Theory of Security"

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Class Breaks

  • Bruce Schneier
  • Edge
  • December 30, 2016

This essay appeared as a response to Edge’s annual question, “what scientific term or concept ought to be more widely known?”

There’s a concept from computer security known as a class break. It’s a particular security vulnerability that breaks not just one system, but an entire class of systems. Examples might be a vulnerability in a particular operating system that allows an attacker to take remote control of every computer that runs on that system’s software. Or a vulnerability in Internet-enabled digital video recorders and webcams that allow an attacker to recruit those devices into a massive botnet…

The Battle for Power on the Internet

Distributed citizen groups and nimble hackers once had the edge. Now governments and corporations are catching up. Who will dominate in the decades ahead?

  • Bruce Schneier
  • The Atlantic
  • October 24, 2013

Danish translation

We’re in the middle of an epic battle for power in cyberspace. On one side are the traditional, organized, institutional powers such as governments and large multinational corporations. On the other are the distributed and nimble: grassroots movements, dissident groups, hackers, and criminals. Initially, the Internet empowered the second side. It gave them a place to coordinate and communicate efficiently, and made them seem unbeatable. But now, the more traditional institutional powers are winning, and winning big. How these two sides fare in the long term, and the fate of the rest of us who don’t fall into either group, is an open question—and one vitally important to the future of the Internet…

How Advanced Is the NSA's Cryptanalysis—And Can We Resist It?

  • Bruce Schneier
  • Wired
  • September 4, 2013

The latest Snowden document is the US intelligence ‘black budget.’ There’s a lot of information in the few pages the Washington Post decided to publish, including an introduction by Director of National Intelligence James Clapper. In it, he drops a tantalizing hint: ‘Also, we are investing in groundbreaking cryptanalytic capabilities to defeat adversarial cryptography and exploit internet traffic.’

Honestly, I’m skeptical. Whatever the NSA has up its top-secret sleeves, the mathematics of cryptography will still be the most secure part of any encryption system. I worry a lot more about poorly designed cryptographic products, software bugs, bad passwords, companies that collaborate with the NSA to leak all or part of the keys, and insecure computers and networks. Those are where the real vulnerabilities are, and where the NSA spends the bulk of its efforts…

Trust in Man/Machine Security Systems

  • Bruce Schneier
  • IEEE Security & Privacy
  • September/October 2013

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I jacked a visitor’s badge from the Eisenhower Executive Office Building in Washington, DC, last month. The badges are electronic; they’re enabled when you check in at building security. You’re supposed to wear it on a chain around your neck at all times and drop it through a slot when you leave.

I kept the badge. I used my body as a shield, and the chain made a satisfying noise when it hit bottom. The guard let me through the gate.

The person after me had problems, though. Some part of the system knew something was wrong, and wouldn’t let her out. Eventually, the guard had to manually override something…

Our Security Models Will Never Work—No Matter What We Do

  • Bruce Schneier
  • Wired
  • March 14, 2013

A core, not side, effect of technology is its ability to magnify power and multiply force—for both attackers and defenders. One side creates ceramic handguns, laser-guided missiles, and new-identity theft techniques, while the other side creates anti-missile defense systems, fingerprint databases, and automatic facial recognition systems.

The problem is that it’s not balanced: Attackers generally benefit from new security technologies before defenders do. They have a first-mover advantage. They’re more nimble and adaptable than defensive institutions like police forces. They’re not limited by bureaucracy, laws, or ethics. They can evolve faster. And entropy is on their side—it’s easier to destroy something than it is to prevent, defend against, or recover from that destruction…

Lance Armstrong and the Prisoners' Dilemma of Doping in Professional Sports

  • Bruce Schneier
  • Wired
  • October 26, 2012

Doping in professional sports is back in the news, as the overwhelming evidence against Lance Armstrong led to his being stripped of his seven Tour de France titles and more. But instead of focusing on the issues of performance-enhancing drugs and whether professional athletes be allowed to take them, I’d like to talk about the security and economic aspects of the issue.

Because drug testing is a security issue. Various sports federations around the world do their best to detect illegal doping, and players do their best to evade the tests. It’s a classic security arms race: Improvements in detection technologies lead to improvements in drug detection evasion, which in turn spur the development of better detection capabilities. Right now, it seems drugs are winning; in some places, these drug tests are described as “intelligence tests”—if you can’t get around them, you don’t deserve to play…

To Profile or Not to Profile? (Part 2)

A Debate between Sam Harris and Bruce Schneier

  • Sam Harris and Bruce Schneier
  • Sam Harris's Blog
  • May 25, 2012

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A profile that encompasses “anyone who could conceivably be Muslim” needs to include almost everyone. Anything less and you’re missing known Muslim airplane terrorist wannabes.

SH:It includes a lot of people, but I wouldn’t say almost everyone. In fact, I just flew out of San Jose this morning and witnessed a performance of security theater so masochistic and absurd that, given our ongoing discussion, it seemed too good to be true. If I hadn’t known better, I would have thought I was being punked by the TSA.

The line at the back-scatter X-ray machines was moving so slowly that I opted for a full-body pat down. What was the hang up? There were …

To Profile or Not to Profile? (Part 1)

A Debate between Sam Harris and Bruce Schneier

  • Sam Harris and Bruce Schneier
  • Sam Harris's Blog
  • May 25, 2012

Introduction by Sam Harris

I recently wrote two articles in defense of “profiling” in the context of airline security (1 & 2), arguing that the TSA should stop doing secondary screenings of people who stand no reasonable chance of being Muslim jihadists. I knew this proposal would be controversial, but I seriously underestimated how inflamed the response would be. Had I worked for a newspaper or a university, I could well have lost my job over it.

One thing that united many of my critics was their admiration for Bruce Schneier. Bruce is an expert on security who has written for …

How Changing Technology Affects Security

  • Bruce Schneier
  • IEEE Security & Privacy
  • March/April 2012

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This essay was republished in Wired on February 24, 2014.

Security is a tradeoff, a balancing act between attacker and defender. Unfortunately, that balance is never static. Changes in technology affect both sides. Society uses new technologies to decrease what I call the scope of defection—what attackers can get away with—and attackers use new technologies to increase it. What’s interesting is the difference between how the two groups incorporate new technologies.

Changes in security systems can be slow. Society has to implement any new security technology as a group, which implies agreement and coordination and—in some instances—a lengthy bureaucratic procurement process. Meanwhile, an attacker can just use the new technology. For example, at the end of the horse-and-buggy era, it was easier for a bank robber to use his new motorcar as a getaway vehicle than it was for a town’s police department to decide it needed a police car, get the budget to buy one, choose which one to buy, buy it, and then develop training and policies for it. And if only one police department did this, the bank robber could just move to another town. Defectors are more agile and adaptable, making them much better at being early adopters of new technology…

High-Tech Cheats in a World of Trust

  • Bruce Schneier
  • New Scientist
  • February 27, 2012

I CAN put my cash card into an ATM anywhere in the world and take out a fistful of local currency, while the corresponding amount is debited from my bank account at home. I don’t even think twice: regardless of the country, I trust that the system will work.

The whole world runs on trust. We trust that people on the street won’t rob us, that the bank we deposited money in last month returns it this month, that the justice system punishes the guilty and exonerates the innocent. We trust the food we buy won’t poison us, and the people we let in to fix our boiler won’t murder us…

Sidebar photo of Bruce Schneier by Joe MacInnis.