Original URL: http://www.theregister.co.uk/2006/02/15/privacy_anonymity/

Privacy and anonymity

Just how far does Big Brother's eye see?

By Kelly Martin

Posted in Security, 15th February 2006 11:43 GMT

Privacy and anonymity on the internet are as important as they are difficult to achieve. Here are some of the the current issues we face, along with a few suggestions on how to be more anonymous.

Online privacy issues are in the news every week now. This is good for us, because when it's newsworthy and notable it means people still care about the privacy of their personal information in some fundamental and important way. Privacy on the internet (or rather, a lack thereof) has been with us for ages, but as technology converges we are all forced to make some important new choices about what we are willing to disclose. Let's start with a few examples.

Recent events have found the Electronic Freedom Foundation warning users not to use Google Desktop's new "search across computers" option, which stores a user's indexed data on Google servers for up to 30 days. It's making headlines, but it's just the tip of the iceberg. In recent weeks we've also heard about government attempts to subpoena information from Yahoo, Microsoft and Google. Perhaps a subpoena for all the files indexed on your Google Desktop is not that far away. Then there are the wiretaps in the US by those three-letter agencies, which we're just hearing about now. First reported by the New York Times, these were wiretaps on US citizens that were sometimes done without requiring court approval at all. I don't know about you, but even when I'm not doing something wrong (which is most of the time), I get very nervous when I hear about privacy issues popping up in this way.

This is on top of all the old news that barely makes headlines anymore: botnet Trojans controlling access to your computer's data and stealing your identity; rampant spyware infections that have been with us for years and are sometimes quite nasty; the fact that only about a third of the public even know what spyware is; and finally, there's even the occasional military breach that exposes the personal information of people who probably value their privacy very much.

Where are we headed with online privacy? Well, perhaps you should publish your darkets secrets in a public blog right now and get it over with. The fact is, we haven't had much, or any, privacy online in quite a while. In the search for privacy, what do we have to do to become anonymous on the internet?

Privacy starts with you

Many people, and security people in particular, value their privacy. We don't like to be tracked and followed. Most of the time this desire does not stem from any malicious intent, but rather from the knowledge of what others who are more malicious than us can do with this information. Our day starts at the office: nothing is private on your office computer, and most people know this already. It is a corporate asset, a tool to conduct business that can (and perhaps, should) be searched at any time. Fine, let's move on to the home computer then. At home one can do "other" things with his computer besides just work.

Most people start with their local system - clearing out their web browser cache, recent URL lists and more with tools of yesteryear like TweakUI. But as broadband connections have become inexpensive and pervasive, we are increasingly being tracked by our IP addresses at home. If you have high speed internet at home, odds are your IP address is relatively static now - cable and DSL modems are often assigned the same IP address for up to a year. Website owners can track your repeat visits much more easily - what time you arrived, how long you stayed, and how often you come back. Nothing new here. Many of us disable cookies in our browsers too, but that semi-static IP address at home can have just as big an impact on your privacy as cookies do.

Often the most anonymous place to surf the web is still with a laptop at a coffee shop with free WiFi, or at an internet cafe. But one day even these places will require a fingerprint for authentication before you're granted access, and you'll have to worry about your fingerprints too. For now however, we have other concerns.

Big name privacy

The big names in the internet world already know quite a bit about us. When Google bought Dejanews and spawned Google Groups, they bought an archive of almost everything written on the Usenet since the very early days. The Internet Archive keeps old copies of your blog or webpage, so even things you've written about and deleted are still there. Google Mail had to deal with all sorts of privacy issues when it first appeared, because it (almost) never deletes any of your email. And now we have the venerable Google Desktop - which, when shared between computers, has your data stored on Google servers for 30 days. Data that might be subpoenaed by someone without your knowledge, a particularly dire fact for those of us who don't even live in the US.

I don't mean to be so hard on Google. They're just an easy target, because they're the new juggernaut. What about Yahoo and MSN? Have you read their respective privacy policy (Yahoo! / MSN) and terms of service (Yahoo! / MSN)? Do you trust them with your data? I for one am glad that I don't live in China. Google's corporate mantra of "do no evil" might be the most reassuring of the three, but this data can still be subpoenaed without your knowledge.

Meanwhile, the trend on the desktop is to index all your local data into a fast internet-style search. Apple's Spotlight on OS X and the Google Desktop have done this for some time; by the end of the year your new Windows Vista system will be able to index all your documents and data too. But imagine when a system like this becomes infected with a Trojan - and that index becomes an easy source for a hacker to search for keywords like "tax", or "credit", or "bank". While it's true the data was always there, it's also becoming more accessible.

Little name privacy

There are all sorts of things we can do to take back our privacy and in doing so, become more anonymous. Some are cumbersome and difficult to do; others are not. For the purpose of this column I'll focus primarily on web access and surfing, because this seems to interest people the most. On the web, there are always logs and those logs point back to your IP address.

I've used SSH port forwarding for years to divert my IP address to somewhere else, but it doesn't add any additional privacy because we (presumably) own the machine we're forwarding to, and therefore a quick lookup of the IP address come back to us. Anonymous web and SOCKS proxies are commonplace, but they are often slow, unreliable, and sporadic. Plus, you must assume that the freely available ones are all logging everything, regardless of what you read, and that the commercial ones that swear they'll never sell your data may or may not be trustworthy - perhaps, but remember that your web surfing history may still be requested by someone tracking you (and thereby have this date given out, without your knowledge) once again.

Using proxies on compromised machines masks your IP address, but it's entirely illegal. If this is what you're using, you deserve to be caught. Just remember that the compromised machine might very well be a honeypot, tracking you back to your source IP.

If broadband access in the home keeps your IP address semi-static, what about using dialup? We can have pre-paid dialup internet access via prepaid cards. I see ads for them all over the subway where I live, and for a moment I thought they might give me some anonyomity. Not a chance. You're still traced back to the CallerID in your home or hotel room, though admittedly every time you connect you'll have a new IP. That might been good enough for most of us.

You could take this one step further and setup your own PBX like the free Asterix PBX to mask your CallerID, and then use the prepaid internet card. While it's entertaining to imagine people going to just extremely, that all seems a little excessive (and non-trivial) to me.

And then there are the liveCDs that help provide some form of anonymity. My favorite today is the Anonym.OS liveCD introduced at SchmooCom recently. Based on the secure-by-default OpenBSD operating system, it goes to the extent of randomizing your (wired or wireless) MAC address on boot, configures Tor onion routing, provides a simple graphical interface, and more. It's a nice step in the right direction. Including these features on a liveCD provides a high level of anonymity and it's a welcome relief. I've installed Tor on my home system as well, but find it rather intrusive - having a liveCD helps avoid that issue. Either way, with Tor your apparent public IP address on a website will appear to keep changing. One thing puzzled me about Anonym.OS, though: I'm curious why a simple tool like netstat, normally included in a base install of OpenBSD, aren't installed. I still like to know what's going on whenever I can.

I think the final frontier is still wireless. If you need a cheap, easy-to-borrow IP address that isn't yours (but is entirely legitimate), there is always one available inside a Wi-Fi coffee shop, an internet cafe, or your local public library. Surf with a cappuccino, along with everyone else. Socialise a bit. Your IP address is a cup of beans. When combined with a system like Anonym.OS, these are good and mostly anonymous options for most people.

What's my IP?

Often an IP address is the only piece of information available to a webmaster to track your visits - assuming you've disabled cookies in your browser and don't mind SessionIDs. Web logs can be subpoenaed too. Did you download Nmap 4.01 recently? My understanding is that Fyodor has had an effective log retention policy for when the feds come knocking, but what about everyone else? Do you use Nessus? Ethereal? Metasploit? Have you tried the latest (and excellent) Back Track pen-test liveCD? These are common tools used for legitimate purposes. Most of us couldn't care less that these downloads are tracked back to our IP. But it's still a useful excercise to go through: finding out how easy it is to map your IP address to an approximate physical location.

Most of us don't have malicious intent, so what about tracking the attackers who do? In the news, the physical location of an IP address used to attack a service is often used to attribute blame to certain country or region of the world. I suspect these addresses are rarely the real origin of the attack, but it's a start. There are dozens of "show my IP" services out there already to find out your public IP address while you're behind a proxy. Need more information? Sometimes a simple WHOIS or dig lookup doesn't suffice. To help find an approximate physical location there's the free IP address locator and the IP-to-country database - both useful tools. Or you can find IP blocks listed by country of origin, in CIDR format if you prefer. The latter is useful if you run web services and receive repeated attacks from countries that don't need access to those services.

As with anything, all these tools can be used for good or evil. "Do no evil," is a mantra that most of us should agree with. I'm happy it was popularized by Google. Sometimes we simply desire to be anonymous for no other reason than to be anonymous, and so that others can't track us. No malicious intent at all. But finding privacy on the internet is not always so easy to do.

Making a choice

Most of us in IT have a certain sense of paranoia about privacy and security - often with good reason. During my own exercise to find out how hard it is to become anonymous, I've come up with a rather simple conclusion: it's all about deciding what amount of privacy and personal information I am willing to give up, in exchange for the goods and services I'm looking to have. As for me, I think I'll keep visiting public Wi-Fi hotspots and use those liveCDs for some time to come.

This article originally appeared in Security Focus.

Copyright © 2006, SecurityFocus