Even though USB memory sticks are quite reliable, there still is the risk of losing it, or even worse, that somebody might steal it from you. The data, you store on your memory stick is probably vital to you; otherwise you wouldn’t bring it with you always. Hence, it is important to backup your memory stick regularly and make sure that nobody is able to access the data on it, if it gets into the wrong hands. It is certainly no solution to just copy all files manually every now and then. It is the first law of any backup strategy: Never backup manually! The reason is obvious. It is easily forgotten, and the probability is high that if you ever need the backup its data is outdated.
To secure the data on an USB stick, you have to encrypt it. Many memory sticks come with encryption software. However, it is not advisable to use it. Usually, one doesn’t know what encryption algorithm was used, and if it was correctly implemented.
My favorite encryption software is the Open Source tool TrueCrypt. It is a well-known program that is very easy to use. If a security leak was found in it, you’ll will probably read about it somewhere, and an update will be available shortly afterwards. You certainly don’t have this guarantee for encryption software that was delivered with your USB stick. Please check out my review about TrueCrypt to learn more about this nifty tool.
Update: Please, also check out my review about TrueCrypt 5.
Another advantage of using TrueCrypt is that it simplifies backups because all your data will be stored in just one file. So you only have to make sure that this file is copied regularly to your hard disk. And if your stick contains confidential data, your backup will be automatically encrypted, too.
The best time to backup your USB stick is whenever you plug it into your PC. If you use the stick on your PC at home and at work, you’ll always have a copy of your data on both computers. To start the backup automatically when you insert the USB stick, you have to create a file named autorun.inf in its root directory with the following contents:
On a Vista machine this will automatically start autrun.bat whenever you connect the USB stick. On a computer with Windows XP, a window will be opened where you can launch the batch file.
TrueCrypt has one disadvantage. You have to specify the size of the TrueCrypt file in advance. The size of this file is always the same even though you only use a fraction of its capacity. So it can take some time until the file is copied to your hard disk. The size of my TrueCrypt file is 1GB. With my stick, it only takes a couple of seconds to copy the file. However, if you want to use a larger file or your stick is slow, you might want to run the backup only if you know that you changed the data on it. The following batch file which should be named autorun.bat solves this problem:
ECHO 1. Backup USB stick
ECHO 2. Quit
set /p choice=
IF '%choice%' == '2' GOTO QUIT
IF '%choice%' == '1' GOTO BACKUP
copy stick.tc "%userprofile%\my documents"
In this example, I assumed that you named your TrueCrypt file stick.tc. If you choose “1″, it will be copied to your documents folder and if you select “2″, no backup will be performed. Of course, you can copy your backup to any other folder.
A nice side effect of this backup solution is that if you ever forget your USB stick at work, you’ll have at least the last version of your data at home. But if you want to make sure that you’ll always have your memory stick with you, then you should check out this post: Never forget your memory stick.