Tuesday, April 20, 2010

Disposing of Computers Responsibly

You don't fall for con games, you use a router with WPA2 wireless, store your passwords securely, keep your operating system and applications updated. You're safe, right?

That depends on how you dispose of old hard drives and computers. If you run Windows, Microsoft recommends cleaning the hard drive with the secure delete command-line application, sdelete. Whatever operating system you run, you may prefer to Use an Ubuntu Live CD to securely wipe your PC's hard drive.

The Frontline video, Ghana: Digital Dumping Ground not only exposes the human health and environmental costs of disposing of computers, but about 8 minutes in, shows data recovery on those same computers that should make the hair on the back of your neck stand up.

One of the reasons I got into computer programming is that it eliminates paper, saves trees, and eliminates paper waste. Electronic devices require electricity, but more importantly, they break or become obsolete very quickly and we replace them. The impact of our obsession with newer, faster computers and other electronics is astounding. But even if we think we are recycling, we might be creating new waste problems in far-away lands as the 60 Minutes Electronic Wasteland video shows (also shows data recovery).

Anyone who reads this blog knows that when my computer became unacceptably slow running Microsoft Windows XP about 9 months ago and I switched to Ubuntu Linux and have been delighted with that decision. File operations that took hours on Windows take minutes on Linux. Everything else seems to run about twice as fast. So if you care about the impact of disposing of your computer (of if you want to save money), install Linux and keep your hardware twice as long. My laptop was bought in 1999 and I run Xubuntu on it (a lightweight version of Ubuntu). It's great for email and web browsing and with a little patience, I can even run a database and a web server on it, even though it only has 500MB memory a 500Ghz processor, and an incredibly slow disk drive.

Thanks to my occasional involvement with UCLUG, I learned of Free Linux PC. They are a fantastic organization that takes donations of old computers, installs Linux on them, and gives them to people who don't have a computer! I've given them a laptop and some memory and I've volunteered at a giveaway at the Greenville Public Library which was a great time. The recipients were pinching themselves.

Here's an old-fashioned recipe for improving environmental, human, and security impacts of your computer usage:


Buy new computers (cell phones, TVs, etc) less often. Use your old ones longer.


Installing Linux can double the useful life of a Windows computer. If that's not for you, then donate any still-working equipment to FreeLinuxPC and they will do it for you.


Recycling sometimes works and is probably better than burning your computer on your front lawn (though it might still be burned in Ghana, Taiwan, or China), certainly better than throwing it in the trash. Even if you don't recycle, if you can find recycled gold watches or other products made from recycled computers, you are supporting an industry that badly needs encouragement.

In any case, make sure to wipe the hard drive before disposing of it!

Thursday, April 15, 2010

POST vs. GET for HTML Form Security (and The Back Button)

At the last GreenJUG meeting, we talked about how you should always use POST instead of GET for any secure web sites. But when you use a POST form on an HTTPS site, navigate away, and click the Back button (on Internet Explorer), you get "The web page you requested is no longer available - try refreshing..." It essentially breaks the back button which UI designers will tell you never to do.

So for me, the rule is, for any view-forms (where the form sends selection criteria for what the user wants to view), make them GET. Such forms tend to submit only the ID number of whatever they are pulling from the database, usually do not involve entering sensitive information, and should work when the users navigates away and uses the back-button. For update forms (where the user submits new data or changes old data) make them POST because it's good to prevent accidental resubmittion and because people tend to enter private and proprietary information on such forms.

Tuesday, April 13, 2010

Passwords Don't Matter

Why Passwords Don't Matter

I set out to write an article about tools to easily manage passwords securely, but when I looked for data on computer crime to encourage people to use better passwords, I discovered a very different story. Most "computer crime" (according to the FBI) is various forms of scams and con games that used to be carried out in person, over the phone, or through the mail, but are now done through online auctions or email. Nothing to do with passwords. This 25-page 2008 Internet Crime Report by the FBI only uses the word "password" twice.

At least for corporations, the big problem seems to be people using the access they were given to do bad things. That happens much more often than people hacking into other accounts.

Computer attacks tend to target applications and the operating system. If you don't keep up with patches, your password won't matter. Source: The Top Cyber Security Risks.

Contrary to the title of this posting, good password practices are important. But what's even more important is to:

1.) Keep your wits about you and cultivate a healthy skepticism before downloading a free game, clicking on an advertisement, or buying something from someone you don't know (e.g. eBay).

2.) Keep your operating system and applications updated. Always choose, "Yes, apply updates right now" and "Of course I'll reboot." Manually check for updates periodically just in case.

3.) Use a tool like Revo Uninstaller to remove applications you are no longer using. Especially anything by Adobe, RealPlayer, toolbars (e.g. Yahoo!), and the Microsoft .NET framework.

When Do Passwords Matter?

I got an email today saying that a web application I used a single time eight years ago had suffered a break-in and warning me that if I used that password for multiple accounts, I should change the passwords to all those accounts. I have over 120 personal accounts, and God knows how many at my various jobs over the last 8 years - how many of those applications have been compromised? Kudos to the organization who discovered the break-in AND alerted me. I think it's safe to assume this is not the only break-in among those 120 applications, nor the only one discovered.

Minimum Effort Password Management

I just read a wonderful article in the Boston Globe Online about the time-wasting, annoying, and mostly useless advice security experts have given us about passwords. So if you want to be secure with the minimum amount of effort, what is the most important thing?

I believe using a different unguessable password for every account is the most important password practice because doing so means that all of your other accounts are safe whenever one of them is compromised - and if you use a computer long enough, accounts WILL be compromised. Some have suggested using X9$bFacebook, X9$bTwitter, X9$bMySpace, but schemes that use the application name, even if it's altered in various ways, are still guessable.

To manage different passwords for every account, you need a password manager. Many people use the "remember passwords" feature of their favorite browser. This is a terrible idea because:
  • It means you are storing your most secure data (your passwords) in your least secure application (your browser)

  • You are going to need to enter activation keys or passwords into software installed on your machine at some point, and you cannot store that in your browser

  • When you go to another computer, or try to switch to another brand of browser, you don't have your passwords.

  • When your hard drive dies, so do all your passwords

  • When you die, so does access to your computer and all your passwords.

So the web browser is not such a good solution. The best I've found (and thanks to a good friend for pointing me to it) is a free, open-source password manager called KeePass which is available for Windows and KeePassX for Linux, Mac, and Windows. I use it with a strong master-password and a tool called DropBox to synch it across my computers. Lifehacker has an article on how to use them together. Once a year, I recommend printing out your KeePass database, writing your master password on it (your Dropbox password will be in your KeePass database), sealing the list in a tamper-evident security envelope, and putting it in your safe deposit box. Then burn last years list (you know, with a match). When your hard drive dies, you have a backup immediately available on your other computers via Dropbox. When you die, there are legal proceedings for your next of kin to access your safe deposit box.

For a less secure, less robust, but easier to use password manager, look at LastPass.