Crypto: Securing Your Files

Your biggest weak point in your business and at home is your PC. It is the single point that can potentially reveal all of your habits, secrets, and personal tastes. Up through the mid-nineties, if you wanted to ascertain a target, you would go through his or her trash, and then use whatever you found to draw up a personality file. With your PC, it is much easier and quicker, and likely would portray a more accurate portrait of your habits.

To secure your files, the first step you should take is to create an encrypted drive on your PC. The process is much easier than you probably think. TrueCrypt is a free, open-source program that uses proven cryptographic methods to secure your data. Once installed on your PC, you can create any number of "drives" - files known as stores - that can be used just like your normal hard drive. The files are non-descript and can have any extension. When you are ready to use it, you "mount" the file, and it becomes whatever drive letter you specify.

As an added bonus, TrueCrypt can provide plausible deniability by encrypting a store within a store. Since an encrypted drive within another encrypted drive is virtually undetectable, you can securely hide your files. Just place a few semi-confidential documents in the main store, and use the secret store for the ultra-classified files.

A method to consider is to use TrueCrypt with a USB drive so you can safeguard your family documents; e.g. take pictures of birth certificates, social security cards, credit cards, passport, etc. within a encrypted store on a small USB key. Imagine the value of the USB if you had to evacuate a disaster area similar to New Orleans, or even if you just needed help during travel after losing your wallet.

You can have faith in the crypto methods as long as you use a strong password. Even a government level effort will take considerable time to retrieve your data.

Now that you know how to keep your files secret, you now need to know how to shred the files that are no longer useful. In case you aren't aware, when you delete something through Windows, it isn't really gone even if you empty your recycle bin. Each deleted file is simply marked for deletion, and isn't really gone until it is eventually overwritten.

Accordingly, you will want to "shred" your files by using a program that deletes the file and then overwrites it with zeroes or random characters. I use my own program which I'll try to find somewhere to post; in the meantime, a popular free choice is The File Shredder.

There are many ways around even this type of security. Government services can reportedly read your monitor using electrical fields (again, reportedly, and I have my doubts), and there are plenty of ways to bypass standard security protocol. As with all counter-intelligence efforts, you want to tailor your security towards your likely threats, the most probable being key monitoring method. There are many programs that capture keystrokes, some of which are harder to detect than most. You can limit the threat by making sure nothing else but your programs are running in task manager. Additionally, there are hardware key loggers that capture everything you type. Only a visual inspection will find a planted device, but if you are using a laptop, you are in the clear.

Basic file security is a must, and with these and a few other pointers, you can keep most of your data private from general threats. If you want to expand your knowledge of cryptology, some resources you may want to check out are:

• The Code Book. A very engaging read about codes and ciphers throughout history, and a great place to start for anyone interested in the field. The book covers everything from medieval codes to WWII, and also explains the complicated modern algorithms in a way you will understand.
• The Crypto-Gram. A monthly newsletter from the absolute guru of the field, Bruce Schneier. As you explore cryptology, you will see more and more about him.

Remember that any encryption measures you take are like putting valuables in a safe - if someone is keen enough, has access and time, they will get in eventually.