USB thumb drives are a handy way for storing important files. Lately, they've become a popular way of transporting data between home computers and work or school. Unless you pay attention to security, they can create big problems.

You might know them as flash drives, key drives or jump drives. They plug into a computer's Universal Serial Bus port and hold anywhere from 16 megabytes to a whopping 8 gigabytes of data. And they're more resilient than DVDs or CDs.

The greatest benefit of thumb drives is their portability. They slip easily into your pocket. But that's also their greatest drawback. They're easily lost or stolen, jeopardizing your sensitive data. Also, they can transfer viruses between computers.

So here are four security tips:

1. GUARD IT CAREFULLY

Many people are careless with thumb drives — often leaving them lying around or attached to key chains. How often have you lost your keys?

Better are ones you can attach to a cord and wear around your neck.

Some thumb drives have cords that connect to the drive's protective removable cap. Forgo these. You want one with a cord that connects to the body of the drive.

2. WATCH OUT FOR VIRUSES

Any computer you connect the drive to should have anti-virus software running. Of course, the virus definitions must be current. The anti-virus software should scan the drive as soon as it is connected.

If the drive isn't from a trusted source, don't connect it to your computer.

3. ENCRYPT YOUR DATA

If your thumb drive falls into the wrong hands, your data are fair game. So protect your files. Encryption will "scramble" your data. It can only be unscrambled with the correct password. Encryption that is 128-bit is very secure.

Many drives come bundled with encryption features. Double-check that the encryption software is not a trial version. Otherwise, you will need to pay to use it once the trial expires.

Once you set up the encryption software, get in the habit of using it. And don't forget to create a strong password.

If your thumb drive doesn't have encryption software, you can buy programs like File Encryption XP, Folder Crypto Password and Folder Lock.

Some manufacturers make drives with a built-in scanner that reads your fingerprint before granting access to the drive. This provides excellent security. Expect to pay a premium for this feature.

Drives with biometric scanners require that software be installed on the computer. This limits where you can access your thumb drive. You might find yourself in a situation where you can't access your data.

4. BACK UP YOUR DATA

Losing your thumb drive is painful, even when the contents are protected.

Always keep multiple copies of important data — particularly when the storage medium is susceptible to loss or damage. Most thumb drives are made of plastic, which isn't always durable.

Contact Kim Komando at www .komando.com/contact.asp.