The chances of travelers losing sensitive data riding on laptops, mobile devices, or USB drives are running high today for anyone who doesn't effectively encrypt their data.

We usually think of encrypting data as a way to protect it from hackers and criminals, but did you ever consider that the U.S. federal government can now search your laptop without probable cause?

Last April, a U.S. Federal Court ruled that U.S. Customs Service agents don't need probable cause to search through laptops and other electronics. The decision is supposed to support Homeland Security's efforts to combat terrorism, but the fact is that 99.999 percent (add a few more nines) of those legally crossing the border into the U.S. are not terrorists but tourists--or business people and students. Or they could be you or I coming home from a trip abroad. If we are willing to let airport inspectors go through our underwear, why would we object to their scrutinizing our laptops?

Without going into a long discussion of the erosion in U.S. citizens' constitutionally guaranteed right to privacy, I will point out that there are many reasons for people to encrypt data on their computers. Encrypting data on your laptop as a defense against Customs agents prying into your personal or business affairs may not work, by the way, since they can demand that you decrypt the drive, folder, or file. And if you don't, they can simply seize the computer.

Government intrusions aside, the best reason to encrypt your data is because you have a very good chance of losing your laptop when you're traveling. I asked a hotel clerk once if there had ever been a problem with items being stolen out of the guests' rooms. "No, not really," he said. "We have had the occasional laptop disappear, but other than that, no one ever loses anything."

A 2006 survey reported on in Computerworld found that more than 80 percent of the 500 companies surveyed had lost one or more laptops containing sensitive information in the previous 12 months. A glaring omission by companies uncovered in the survey was the absence of knowledge by the IT departments about where sensitive data resides. Sixty-four percent of companies surveyed reported they had never conducted an inventory of sensitive "consumer" information or of employee data. Not only did employees lose laptops with sensitive information, but so did contractors. Those little USB drives with increasingly large storage capacities also pose a major risk. How long does it take to determine exactly what data is missing after a laptop is lost or stolen? The question is meaningless because the data is never accounted for, according to IT survey respondents.

Today, many people use BlackBerries and other handheld devices to transmit and receive emails, which undoubtedly contain sensitive information. The recently published book "Where Have All the Emails Gone" by David Gewirtz discusses the frightening lack of security in White House email communications and the staff members' scary policy of sending email through non-government servers.

Last week in TNT, we cited several approaches to PC encryption, including the open-source TrueCrypt application, and this week we'll discuss another approach. While software encryption has its place, hardware encryption can be a lot more effective if someone is really determined to find out what information you are trying to keep confidential. Software encryption programs are a good first line of defense, but they are vulnerable to a variety of encryption attacks. Hardware-based encryption can offer a stronger defense.

IronKey offers a line of hardware-encrypted USB flash drives that take data security to the next level. While not perfect, according to users, who cite convenience issues the company admits it is still is working on, most find the USB drives highly effective in securing data, whether it needs to be moved between computers or not. One feature that is a convenience is that IronKey's drives don't need software, drivers, or administrator privileges, so it's easy to move the drive from one computer to another.

The big draw to this device is that if it's ever lost or stolen, there is almost no chance your data will be compromised. The drive is tamper-proof and even waterproof. It has a number of sophisticated features that render the data useless if anyone ever tries to tamper with the device. It's not uncommon to try to remove the flash memory chip and mount it on another computer, something to which IronKey drives are not vulnerable.

A common trick to crack a regular software-encrypted USB drive is to plug it into another computer and then use dozens or thousands of hijacked parallel machines on a botnet to crack the password or key. A hardware-based encryption device can help prevent this approach by not mounting onto another PC until the correct password has been entered. The IronKey drive generates its own encryption keys from a true random-number generator. The devices aren't inexpensive, costing around $125, depending on the size, but they have the added feature of secure Internet browsing. This can come in handy if you know someone is trying to break into your network and you want to discover who it is without scaring off the potential intruder.

We may not be able to prevent the theft or loss of every laptop or USB drive, but by using a hardware-encrypted storage device to transport sensitive files, we can prevent most data from falling into the wrong hands.