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Keep your data safe at the border

There's no right to privacy at international borders. For those of us with laptops, this presents a major problem: how to get through U.S. Customs without Uncle Sam peeking at every e-mail.

Chris Soghoian
Christopher Soghoian delves into the areas of security, privacy, technology policy and cyber-law. He is a student fellow at Harvard University's Berkman Center for Internet and Society , and is a PhD candidate at Indiana University's School of Informatics. His academic work and contact information can be found by visiting www.dubfire.net/chris/.
Chris Soghoian
3 min read

There is no right to privacy at international borders. For those of us with laptops, this presents a pretty major problem: How do we get through U.S. Customs with our beloved portable devices, without having Uncle Sam peeking at every e-mail we've sent, every MP3 we've listened to, and every "home movie" we've made?

The obvious solution, encryption, is not enough. Non-Americans have no right to enter the U.S. Don't want to hand over your encryption keys? No problem--but you will be put on the next airplane back to your home country (if you're lucky...If the government really doesn't like you, you may end up getting sent to Syria).

Those of us "lucky" enough to have a U.S. passport may be forced to enter the password for the data, if we want to avoid having the devices seized and never returned.

For travelers heading to countries other than the U.S., it can be even worse. Refusing to hand over your encryption key to a lawful request by British Police can result in jail time. Ouch.

CNET News.com's Declan McCullagh posted a guide to securing laptops for border searches back in March. The Electronic Frontier Foundation's Jennifer Granick wrote a blog post on the subject recently, in which she broke down the case law and offered a bit of advice. While both of these are interesting reads, neither includes the practical solution which I use.

Chris' Guide to Safe International Data Transport

  1. Before going on any international trip, back up all of your important and potentially embarrassing, incriminating, or troubling data. This includes any copyrighted content which you may not be able to prove you own.
  2. Create an encrypted disk image/encrypted folder of that data. This can be done with Pretty Good Privacy, Truecrypt, or software built into many operating systems.
  3. Remember the password. This is very important, as if you forget it, you lose all your data.
  4. Upload the encrypted data to a reliable place on the Internet (or two). Personally, I use Amazon S3, which charges 15 cents per GB-month of storage plus 17 cents per GB of data transfer.
  5. Wipe your laptop clean (do this properly, or the data may be accessible after the fact with forensics software), and install a fresh copy of your OS onto it.
  6. Travel. You should have no problem at U.S. Customs (or in any other country) as you won't have anything problematic on your computer.
  7. At your hotel/office, fire up your Web browser and download the encrypted data file from Amazon's servers.
  8. Decrypt the data.

Once you are done with your trip, you can simply re-encrypt the data, upload it to Amazon again, and wipe the disk clean.

For those of you traveling to countries (or places in the U.S.) with slow Internet connections, you may wish to burn your encrypted data to a DVD and FedEx it to your destination. Do it a few days before you leave, and you should know before you get on the airplane if the disk made it to your destination safely by checking the delivery status online.

I realize that I take paranoia to a more extreme level than most, but I find that this technique works really, really well for me. For those of you who are even more paranoid, and are worried about customs agents being able to recover the deleted data from your laptop disk, you may wish to avoid keeping the decrypted data on your laptop at all (while on the trip). Portable flash drives are quite cheap these days, and can be easily destroyed (a microwave, a hammer, driving over them in a rental car, etc.) once your trip is done.

Disclosure: Jennifer Granick represented me, pro-bono, in my civil troubles with TSA back in 2006 and 2007.