Entries Tagged "web"

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More European Chip and Pin Insecurity

Optimised to Fail: Card Readers for Online Banking,” by Saar Drimer, Steven J. Murdoch, and Ross Anderson.

Abstract

The Chip Authentication Programme (CAP) has been introduced by banks in Europe to deal with the soaring losses due to online banking fraud. A handheld reader is used together with the customer’s debit card to generate one-time codes for both login and transaction authentication. The CAP protocol is not public, and was rolled out without any public scrutiny. We reverse engineered the UK variant of card readers and smart cards and here provide the first public description of the protocol. We found numerous weaknesses that are due to design errors such as reusing authentication tokens, overloading data semantics, and failing to ensure freshness of responses. The overall strategic error was excessive optimisation. There are also policy implications. The move from signature to PIN for authorising point-of-sale transactions shifted liability from banks to customers; CAP introduces the same problem for online banking. It may also expose customers to physical harm.

EDITED TO ADD (3/12): More info.

Posted on March 5, 2009 at 12:45 PMView Comments

Here Comes Everybody Review

In 1937, Ronald Coase answered one of the most perplexing questions in economics: if markets are so great, why do organizations exist? Why don’t people just buy and sell their own services in a market instead? Coase, who won the 1991 Nobel Prize in Economics, answered the question by noting a market’s transaction costs: buyers and sellers need to find one another, then reach agreement, and so on. The Coase theorem implies that if these transaction costs are low enough, direct markets of individuals make a whole lot of sense. But if they are too high, it makes more sense to get the job done by an organization that hires people.

Economists have long understood the corollary concept of Coase’s ceiling, a point above which organizations collapse under their own weight—where hiring someone, however competent, means more work for everyone else than the new hire contributes. Software projects often bump their heads against Coase’s ceiling: recall Frederick P. Brooks Jr.’s seminal study, The Mythical Man-Month (Addison-Wesley, 1975), which showed how adding another person onto a project can slow progress and increase errors.

What’s new is something consultant and social technologist Clay Shirky calls "Coase’s Floor," below which we find projects and activities that aren’t worth their organizational costs—things so esoteric, so frivolous, so nonsensical, or just so thoroughly unimportant that no organization, large or small, would ever bother with them. Things that you shake your head at when you see them and think, "That’s ridiculous."

Sounds a lot like the Internet, doesn’t it? And that’s precisely Shirky’s point. His new book, Here Comes Everybody: The Power of Organizing Without Organizations, explores a world where organizational costs are close to zero and where ad hoc, loosely connected groups of unpaid amateurs can create an encyclopedia larger than the Britannica and a computer operating system to challenge Microsoft’s.

Shirky teaches at New York University’s Interactive Telecommunications Program, but this is no academic book. Sacrificing rigor for readability, Here Comes Everybody is an entertaining as well as informative romp through some of the Internet’s signal moments—the Howard Dean phenomenon, Belarusian protests organized on LiveJournal, the lost cellphone of a woman named Ivanna, Meetup.com, flash mobs, Twitter, and more—which Shirky uses to illustrate his points.

The book is filled with bits of insight and common sense, explaining why young people take better advantage of social tools, how the Internet affects social change, and how most Internet discourse falls somewhere between dinnertime conversation and publishing.

Shirky notes that "most user-generated content isn’t ‘content’ at all, in the sense of being created for general consumption, any more than a phone call between you and a sibling is ‘family-generated content.’ Most of what gets created on any given day is just the ordinary stuff of life—gossip, little updates, thinking out loud—but now it’s done in the same medium as professionally produced material. Unlike professionally produced material, however, Internet content can be organized after the fact."

No one coordinates Flickr’s 6 million to 8 million users. Yet Flickr had the first photos from the 2005 London Transport bombings, beating the traditional news media. Why? People with cellphone cameras uploaded their photos to Flickr. They coordinated themselves using tools that Flickr provides. This is the sort of impromptu organization the Internet is ideally suited for. Shirky explains how these moments are harbingers of a future that can self-organize without formal hierarchies.

These nonorganizations allow for contributions from a wider group of people. A newspaper has to pay someone to take photos; it can’t be bothered to hire someone to stand around London underground stations waiting for a major event. Similarly, Microsoft has to pay a programmer full time, and Encyclopedia Britannica has to pay someone to write articles. But Flickr can make use of a person with just one photo to contribute, Linux can harness the work of a programmer with little time, and Wikipedia benefits if someone corrects just a single typo. These aggregations of millions of actions that were previously below the Coasean floor have enormous potential.

But a flash mob is still a mob. In a world where the Coasean floor is at ground level, all sorts of organizations appear, including ones you might not like: violent political organizations, hate groups, Holocaust deniers, and so on. (Shirky’s discussion of teen anorexia support groups makes for very disturbing reading.) This has considerable implications for security, both online and off.

We never realized how much our security could be attributed to distance and inconvenience—how difficult it is to recruit, organize, coordinate, and communicate without formal organizations. That inadvertent measure of security is now gone. Bad guys, from hacker groups to terrorist groups, will use the same ad hoc organizational technologies that the rest of us do. And while there has been some success in closing down individual Web pages, discussion groups, and blogs, these are just stopgap measures.

In the end, a virtual community is still a community, and it needs to be treated as such. And just as the best way to keep a neighborhood safe is for a policeman to walk around it, the best way to keep a virtual community safe is to have a virtual police presence.

Crime isn’t the only danger; there is also isolation. If people can segregate themselves in ever-increasingly specialized groups, then they’re less likely to be exposed to alternative ideas. We see a mild form of this in the current political trend of rival political parties having their own news sources, their own narratives, and their own facts. Increased radicalization is another danger lurking below the Coasean floor.

There’s no going back, though. We’ve all figured out that the Internet makes freedom of speech a much harder right to take away. As Shirky demonstrates, Web 2.0 is having the same effect on freedom of assembly. The consequences of this won’t be fully seen for years.

Here Comes Everybody covers some of the same ground as Yochai Benkler’s Wealth of Networks. But when I had to explain to one of my corporate attorneys how the Internet has changed the nature of public discourse, Shirky’s book is the one I recommended.

This essay previously appeared in IEEE Spectrum.

EDITED TO ADD (12/13): Interesting Clay Shirky podcast.

Posted on November 25, 2008 at 7:39 AMView Comments

Online Age Verification

A discussion of a security trade-off:

Child-safety activists charge that some of the age-verification firms want to help Internet companies tailor ads for children. They say these firms are substituting one exaggerated threat—the menace of online sex predators—with a far more pervasive danger from online marketers like junk food and toy companies that will rush to advertise to children if they are told revealing details about the users.

It’s an old story: protecting against the rare and spectacular by making yourself more vulnerable to the common and pedestrian.

Posted on November 21, 2008 at 11:47 AMView Comments

Censorship in Dubai

I was in Dubai last weekend for the World Economic Forum Summit on the Global Agenda. (I was on the “Future of the Internet” council; fellow council members Ethan Zuckerman and Jeff Jarvis have written about the event.)

As part of the United Arab Emirates, Dubai censors the Internet:

The government of the United Arab Emirates (UAE) pervasively filters Web sites that contain pornography or relate to alcohol and drug use, gay and lesbian issues, or online dating or gambling. Web-based applications and religious and political sites are also filtered, though less extensively. Additionally, legal controls limit free expression and behavior, restricting political discourse and dissent online.

More detail here.

What was interesting to me about how reasonable the execution of the policy was. Unlike some countries—China for example—that simply block objectionable content, the UAE displays a screen indicating that the URL has been blocked and offers information about its appeals process.

Posted on November 12, 2008 at 12:56 PMView Comments

Clickjacking

Good Q&A on clickjacking:

In plain English, clickjacking lets hackers and scammers hide malicious stuff under the cover of the content on a legitimate site. You know what happens when a carjacker takes a car? Well, clickjacking is like that, except that the click is the car.

“Clickjacking” is a stunningly sexy name, but the vulnerability is really just a variant of cross-site scripting. We don’t know how bad it really is, because the details are still being withheld. But the name alone is causing dread.

EDITED TO ADD (10/13): More details.

Posted on October 6, 2008 at 1:45 PMView Comments

New Cross-Site Request Forgery Attacks

Interesting:

CSRF vulnerabilities occur when a website allows an authenticated user to perform a sensitive action but does not verify that the user herself is invoking that action. The key to understanding CSRF attacks is to recognize that websites typically don’t verify that a request came from an authorized user. Instead they verify only that the request came from the browser of an authorized user. Because browsers run code sent by multiple sites, there is a danger that one site will (unbeknownst to the user) send a request to a second site, and the second site will mistakenly think that the user authorized the request.

If a user visits an attacker’s website, the attacker can force the user’s browser to send a request to a page that performs a sensitive action on behalf of the user. The target website sees a request coming from an authenticated user and happily performs some action, whether it was invoked by the user or not. CSRF attacks have been confused with Cross-Site Scripting (XSS) attacks, but they are very different. A site completely protected from XSS is still vulnerable to CSRF attacks if no protections are taken.

Paper here.

Posted on October 6, 2008 at 5:42 AMView Comments

BT, Phorm, and Me

Over the past year I have gotten many requests, both public and private, to comment on the BT and Phorm incident.

I was not involved with BT and Phorm, then or now. Everything I know about Phorm and BT’s relationship with Phorm came from the same news articles you read. I have not gotten involved as an employee of BT. But anything I say is—by definition—said by a BT executive. That’s not good.

So I’m sorry that I can’t write about Phorm. But—honestly—lots of others have been giving their views on the issue.

Posted on September 8, 2008 at 6:23 AMView Comments

Privacy Policies: Perception vs. Reality

New paper: “What Californians Understand About Privacy Online,” by Chris Jay Hoofnagle and Jennifer King. From the abstract:

A gulf exists between California consumers’ understanding of online rules and common business practices. For instance, Californians who shop online believe that privacy policies prohibit third-party information sharing. A majority of Californians believes that privacy policies create the right to require a website to delete personal information upon request, a general right to sue for damages, a right to be informed of security breaches, a right to assistance if identity theft occurs, and a right to access and correct data.

These findings show that California consumers overvalue the mere fact that a website has a privacy policy, and assume that websites carrying the label have strong, default rules to protect personal data. In a way, consumers interpret “privacy policy” as a quality seal that denotes adherence to some set of standards. Website operators have little incentive to correct this misperception, thus limiting the ability of the market to produce outcomes consistent with consumers’ expectations. Drawing upon earlier work, we conclude that because the term “privacy policy” has taken on a specific meaning in the minds of consumers, its use should be limited to contexts where businesses provide a set of protections that meet consumers’ expectations.

Posted on September 4, 2008 at 1:15 PMView Comments

Cyberattack Against Georgia Preceded Real Attack

This is interesting:

Exactly who was behind the cyberattack is not known. The Georgian government blamed Russia for the attacks, but the Russian government said it was not involved. In the end, Georgia, with a population of just 4.6 million and a relative latecomer to the Internet, saw little effect beyond inaccessibility to many of its government Web sites, which limited the government’s ability to spread its message online and to connect with sympathizers around the world during the fighting with Russia.

[…]

In Georgia, media, communications and transportation companies were also attacked, according to security researchers. Shadowserver saw the attack against Georgia spread to computers throughout the government after Russian troops entered the Georgian province of South Ossetia. The National Bank of Georgia’s Web site was defaced at one point. Images of 20th-century dictators as well as an image of Georgia’s president, Mr. Saakashvili, were placed on the site. “Could this somehow be indirect Russian action? Yes, but considering Russia is past playing nice and uses real bombs, they could have attacked more strategic targets or eliminated the infrastructure kinetically,” said Gadi Evron, an Israeli network security expert. “The nature of what’s going on isn’t clear,” he said.

[…]

In addition to D.D.O.S. attacks that crippled Georgia’s limited Internet infrastructure, researchers said there was evidence of redirection of Internet traffic through Russian telecommunications firms beginning last weekend. The attacks continued on Tuesday, controlled by software programs that were located in hosting centers controlled by a Russian telecommunications firms. A Russian-language Web site, stopgeorgia.ru, also continued to operate and offer software for download used for D.D.O.S. attacks.

Welcome to 21st century warfare.

“It costs about 4 cents per machine,” Mr. Woodcock said. “You could fund an entire cyberwarfare campaign for the cost of replacing a tank tread, so you would be foolish not to.”

Posted on August 18, 2008 at 1:11 PMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.