Lab

Privacy Software

There's a saying that those with nothing to hide have nothing to fear. But who has nothing to hide? We all value our privacy, and that's equally true online. Maybe you've spent the weekend surfing recruitment Web sites, but you'd rather the boss didn't spot that when you take your laptop into work. Or perhaps you enjoy the humour of sites such as www.theonion.com, but you'd rather your kids didn't see the strong language and saucy adverts. With the right Internet privacy software, you can remove all trace of your online activities. We test six options to see which can really keep nosey parkers out of your PC.

Why do I need privacy software?

When you close your browser after a few minutes' surfing, you'll quickly forget most of the sites you've seen. But your PC won't. Everywhere you've been is safely noted in the browser's History file, easily accessible to anyone who uses your PC. And they don't even have to access it deliberately. In most browsers, as soon as you start typing the address (also known as a 'uniform resource locator' or URL) you want to go to, the addresses of previous sites pop up below.

These records include URLs you may never have typed in yourself, but were taken to by links or pop-up windows. You may not even have noticed a window that opened in the background. Then there are the times you guess a URL wrongly, and end up looking at something completely unexpected.

That's not all your browser remembers. The Search function in Explorer is handy, but not very discreet: click Previous Search and you get a list of things you've searched for before. Search engines such as www.google.co.uk and www.askjeeves.com do the same. Even worse, elements of every page you visit remain in 'temporary Internet files' hidden on your hard disk. You may not know where to look for them, but plenty of people do.

Most commercial, and many non-commercial, Web sites record information about you in 'cookies', small data files stored on your own PC. As well as indicating where you've been, these may include log-on details, so anyone else sitting at your PC could see all your previous transactions on sites such as www.amazon.com. Even more critical information may be betrayed by features like Internet Explorer's AutoComplete, which helpfully fills in forms with personal details you previously entered elsewhere.

Some of these functions can be turned off in your browser. You can, for instance, go to Tools and then Internet Options in Internet Explorer and tell the browser not to record any of the Web addresses you visit. You can also tell Internet Explorer to delete all the temporary Internet files, photos and html files, and cookies that it's storing for you.

As soon as you start surfing once more, though, Explorer will start storing the same temporary Internet files once again. Even worse, the files you thought you'd deleted aren't really gone at all. When you 'delete' a file in Windows, it first goes into the Recycle Bin. Even after you empty this, all the data remains intact on the disk - the only thing erased is the reference to it in the file table. Until Windows needs that particular bit of space on the hard disk, these files won't be overwritten and can easily be recovered by a simple piece of software available for less than twenty quid.

Geeks with more technical know-how, and time, could even recover enough of the file to reconstruct it after Windows has written over it. Private detectives, law enforcement agents and business rivals could potentially do the same. If you really want to delete something, you have to do it properly.

What should I look for?

To illustrate how unsafe it can be to rely on file deletion, we created a disk partition filled with typical Internet files, including cookies, .gif and .jpg images, HTML files, Flash movies and .exe files. We deleted all the files in the normal way and emptied the Recycle Bin. We then ran Active@Undelete, a readily available file recovery utility. It found all 182 files and recovered them successfully in a couple of minutes. Although the original filenames weren't preserved, all the files could be opened and viewed as normal. Imagine if these were URLs, personal information and pictures that you thought you'd deleted.

To make sure you don't leave these kinds of traces behind, you need Internet Privacy software that can not only delete telltale files, but also knows where to find them. Internet Explorer doesn't leave all its traces in one place, so if you had to delete them all manually, there's a chance you'll miss something.

Not everyone uses Internet Explorer. Privacy software should, at very least, also be able to find and destroy the traces left behind by the other most common browser, Netscape Navigator. Ideally, it should also be able to work with other browsers such as Opera and Mozilla as well.

As well as deleting browser traces, privacy software should also be able to get rid of other traces of your online activities, left in programs such as Windows Media Player or Real Networks RealPlayer. If you want to specify files of your own choosing for secure deletion, you should be able to do that too. The software should also be able to clear things like the Windows search function records. Finally, it should be able to overwrite the index.dat file, removing an otherwise undeletable record of all the Web sites you've ever visited.

Once you've decided which files to get rid of, the software should securely delete the files in such a way as to make them as difficult to recover as possible. This usually means overwriting the area of the hard drive on which they were stored. The simplest option is to delete a file, then overwrite its disk space with zeroes or random data. For better protection, deleted files can be overwritten three or more times, as recommended by the US Department of Defense.

If the people snooping around on your hard drive are the CIA, even this might not be enough. The US Department of Defense recommends you 'disintegrate, incinerate, pulverise, shred, or melt' your hard drive for absolute security. For most people, overwriting several times will be enough. No one will be able to find traces of private or potentially embarrassing online activities and you won't have to worry about passwords falling into the wrong hands.

Buying Decisions

All these programs are compact, capable, and easy to get to grips with. As a good all-rounder that hugely improves your privacy without too many technical decisions, Window Washer wins the day. If Microsoft Internet Explorer is your only browser, and you're not worried about clearing out lists of recent files from general-purpose applications, Aladdin Internet Cleanup offers less stringently secure deletion but a few more features.