Entries Tagged "Twitter"

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Get Your Terrorist Alerts on Facebook and Twitter

Colors are so last decade:

The U.S. government’s new system to replace the five color-coded terror alerts will have two levels of warnings ­ elevated and imminent ­ that will be relayed to the public only under certain circumstances for limited periods of time, sometimes using Facebook and Twitter, according to a draft Homeland Security Department plan obtained by The Associated Press.

Some terror warnings could be withheld from the public entirely if announcing a threat would risk exposing an intelligence operation or a current investigation, according to the government’s confidential plan.

Like a carton of milk, the new terror warnings will each come with a stamped expiration date.

Specific and limited are good. Twitter and Facebook: I’m not so sure.

But what could go wrong?

An errant keystroke touched off a brief panic Thursday at the University of Illinois at Urbana-Champaign when an emergency message accidentally was sent out saying an “active shooter” was on campus.

The first message was sent on the university’s emergency alert system at 10:40 a.m., reaching 87,000 cellphones and email addresses, according to the university.

The university corrected the false alarm about 12 minutes later and said the alert was caused when a worker updating the emergency messaging system inadvertently sent the message rather than saving it.

The emails are designed to go out quickly in the event of an emergency, so the false alarm could not be canceled before it went out, the university said.

Posted on April 8, 2011 at 1:23 PM • View Comments

Hacking HTTP Status Codes

One website can learn if you’re logged into other websites.

When you visit my website, I can automatically and silently determine if you’re logged into Facebook, Twitter, Gmail and Digg. There are almost certainly thousands of other sites with this issue too, but I picked a few vulnerable well known ones to get your attention. You may not care that I can tell you’re logged into Gmail, but would you care if I could tell you’re logged into one or more porn or warez sites? Perhaps http://oppressive-regime.example.org/ would like to collect a list of their users who are logged into http://controversial-website.example.com/?

Posted on February 2, 2011 at 2:26 PM • View Comments

Reading Me

The number of different ways to read my essays, commentaries, and links has grown recently. Here’s the rundown:

I think that about covers it for useful distribution formats right now.

EDITED TO ADD (6/20): One more; there’s a Crypto-Gram podcast.

Posted on June 15, 2010 at 1:05 PM • View Comments

Reacting to Security Vulnerabilities

Last month, researchers found a security flaw in the SSL protocol, which is used to protect sensitive web data. The protocol is used for online commerce, webmail, and social networking sites. Basically, hackers could hijack an SSL session and execute commands without the knowledge of either the client or the server. The list of affected products is enormous.

If this sounds serious to you, you’re right. It is serious. Given that, what should you do now? Should you not use SSL until it’s fixed, and only pay for internet purchases over the phone? Should you download some kind of protection? Should you take some other remedial action? What?

If you read the IT press regularly, you’ll see this sort of question again and again. The answer for this particular vulnerability, as for pretty much any other vulnerability you read about, is the same: do nothing. That’s right, nothing. Don’t panic. Don’t change your behavior. Ignore the problem, and let the vendors figure it out.

There are several reasons for this. One, it’s hard to figure out which vulnerabilities are serious and which are not. Vulnerabilities such as this happen multiple times a month. They affect different software, different operating systems, and different web protocols. The press either mentions them or not, somewhat randomly; just because it’s in the news doesn’t mean it’s serious.

Two, it’s hard to figure out if there’s anything you can do. Many vulnerabilities affect operating systems or Internet protocols. The only sure fix would be to avoid using your computer. Some vulnerabilities have surprising consequences. The SSL vulnerability mentioned above could be used to hack Twitter. Did you expect that? I sure didn’t.

Three, the odds of a particular vulnerability affecting you are small. There are a lot of fish in the Internet, and you’re just one of billions.

Four, often you can’t do anything. These vulnerabilities affect clients and servers, individuals and corporations. A lot of your data isn’t under your direct control—it’s on your web-based email servers, in some corporate database, or in a cloud computing application. If a vulnerability affects the computers running Facebook, for example, your data is at risk, whether you log in to Facebook or not.

It’s much smarter to have a reasonable set of default security practices and continue doing them. This includes:

1. Install an antivirus program if you run Windows, and configure it to update daily. It doesn’t matter which one you use; they’re all about the same. For Windows, I like the free version of AVG Internet Security. Apple Mac and Linux users can ignore this, as virus writers target the operating system with the largest market share.

2. Configure your OS and network router properly. Microsoft’s operating systems come with a lot of security enabled by default; this is good. But have someone who knows what they’re doing check the configuration of your router, too.

3. Turn on automatic software updates. This is the mechanism by which your software patches itself in the background, without you having to do anything. Make sure it’s turned on for your computer, OS, security software, and any applications that have the option. Yes, you have to do it for everything, as they often have separate mechanisms.

4. Show common sense regarding the Internet. This might be the hardest thing, and the most important. Know when an email is real, and when you shouldn’t click on the link. Know when a website is suspicious. Know when something is amiss.

5. Perform regular backups. This is vital. If you’re infected with something, you may have to reinstall your operating system and applications. Good backups ensure you don’t lose your data—documents, photographs, music—if that becomes necessary.

That’s basically it. I could give a longer list of safe computing practices, but this short one is likely to keep you safe. After that, trust the vendors. They spent all last month scrambling to fix the SSL vulnerability, and they’ll spend all this month scrambling to fix whatever new vulnerabilities are discovered. Let that be their problem.

Posted on December 10, 2009 at 1:13 PM • View Comments

File Deletion

File deletion is all about control. This used to not be an issue. Your data was on your computer, and you decided when and how to delete a file. You could use the delete function if you didn’t care about whether the file could be recovered or not, and a file erase program—I use BCWipe for Windows—if you wanted to ensure no one could ever recover the file.

As we move more of our data onto cloud computing platforms such as Gmail and Facebook, and closed proprietary platforms such as the Kindle and the iPhone, deleting data is much harder.

You have to trust that these companies will delete your data when you ask them to, but they’re generally not interested in doing so. Sites like these are more likely to make your data inaccessible than they are to physically delete it. Facebook is a known culprit: actually deleting your data from its servers requires a complicated procedure that may or may not work. And even if you do manage to delete your data, copies are certain to remain in the companies’ backup systems. Gmail explicitly says this in its privacy notice.

Online backups, SMS messages, photos on photo sharing sites, smartphone applications that store your data in the network: you have no idea what really happens when you delete pieces of data or your entire account, because you’re not in control of the computers that are storing the data.

This notion of control also explains how Amazon was able to delete a book that people had previously purchased on their Kindle e-book readers. The legalities are debatable, but Amazon had the technical ability to delete the file because it controls all Kindles. It has designed the Kindle so that it determines when to update the software, whether people are allowed to buy Kindle books, and when to turn off people’s Kindles entirely.

Vanish is a research project by Roxana Geambasu and colleagues at the University of Washington. They designed a prototype system that automatically deletes data after a set time interval. So you can send an email, create a Google Doc, post an update to Facebook, or upload a photo to Flickr, all designed to disappear after a set period of time. And after it disappears, no one—not anyone who downloaded the data, not the site that hosted the data, not anyone who intercepted the data in transit, not even you—will be able to read it. If the police arrive at Facebook or Google or Flickr with a warrant, they won’t be able to read it.

The details are complicated, but Vanish breaks the data’s decryption key into a bunch of pieces and scatters them around the web using a peer-to-peer network. Then it uses the natural turnover in these networks—machines constantly join and leave—to make the data disappear. Unlike previous programs that supported file deletion, this one doesn’t require you to trust any company, organisation, or website. It just happens.

Of course, Vanish doesn’t prevent the recipient of an email or the reader of a Facebook page from copying the data and pasting it into another file, just as Kindle’s deletion feature doesn’t prevent people from copying a book’s files and saving them on their computers. Vanish is just a prototype at this point, and it only works if all the people who read your Facebook entries or view your Flickr pictures have it installed on their computers as well; but it’s a good demonstration of how control affects file deletion. And while it’s a step in the right direction, it’s also new and therefore deserves further security analysis before being adopted on a wide scale.

We’ve lost the control of data on some of the computers we own, and we’ve lost control of our data in the cloud. We’re not going to stop using Facebook and Twitter just because they’re not going to delete our data when we ask them to, and we’re not going to stop using Kindles and iPhones because they may delete our data when we don’t want them to. But we need to take back control of data in the cloud, and projects like Vanish show us how we can.

Now we need something that will protect our data when a large corporation decides to delete it.

This essay originally appeared in The Guardian.

EDITED TO ADD (9/30): Vanish has been broken, paper here.

Posted on September 10, 2009 at 6:08 AM • View Comments

Risks of Cloud Computing

Excellent essay by Jonathan Zittrain on the risks of cloud computing:

The cloud, however, comes with real dangers.

Some are in plain view. If you entrust your data to others, they can let you down or outright betray you. For example, if your favorite music is rented or authorized from an online subscription service rather than freely in your custody as a compact disc or an MP3 file on your hard drive, you can lose your music if you fall behind on your payments—or if the vendor goes bankrupt or loses interest in the service. Last week Amazon apparently conveyed a publisher’s change-of-heart to owners of its Kindle e-book reader: some purchasers of Orwell’s “1984” found it removed from their devices, with nothing to show for their purchase other than a refund. (Orwell would be amused.)

Worse, data stored online has less privacy protection both in practice and under the law. A hacker recently guessed the password to the personal e-mail account of a Twitter employee, and was thus able to extract the employee’s Google password. That in turn compromised a trove of Twitter’s corporate documents stored too conveniently in the cloud. Before, the bad guys usually needed to get their hands on people’s computers to see their secrets; in today’s cloud all you need is a password.

Thanks in part to the Patriot Act, the federal government has been able to demand some details of your online activities from service providers—and not to tell you about it. There have been thousands of such requests lodged since the law was passed, and the F.B.I.’s own audits have shown that there can be plenty of overreach—perhaps wholly inadvertent—in requests like these.

Here’s me on cloud computing.

Posted on July 30, 2009 at 7:06 AM • View Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.