If I travel to the US and had privacy concerns (for instance may be I was afraid that a rogue customs official may steal said data) what is the current recommended best practice to avoid this?
There are cases of customs and immigration demanding the passwords to phones or laptops, and then taking them out of sight of the passenger to use them and search them. Apparently by law you must provide these passwords when asked, and you may not follow the officers around to see what they do with your devices (such as putting USB sticks into them to copy data.)
(For the specific question of "can they really do that?" see
- Laptop Searches by Customs - UK and US
- Laptop/mobile device in countries with Sharia
- Have anyone experienced inspection of their laptop or digital media content?
- US and Canada border crossing and computer privacy: What do I need to know?
The best prevention for this problem is almost certainly not to have the sensitive data on the laptop at all. It can be in some sort of cloud storage and you can copy it onto your laptop after you clear the border.
The second best prevention is to have the data with you but hidden. People have suggested a dual-boot setup, where the machine is booted into one OS that does not have access to the sensitive data at all, and only if they reboot the machine will they know that another OS even exists. Hidden encrypted partitions have also been suggested. While this may work, if it is noticed it will suddenly make everyone very suspicious and get you a lot more attention, so it may not be worth the risk. You can also use USB devices that don't appear to be USB devices at first glance - I own a beer bottle opener USB and I know someone with a watch USB - to carry the data. While I have seen laptops and phones searched on episodes of Border Security (generally snooping through emails to see if someone is coming into the country to work or to stay forever) I have never seen USB sticks searched, and I suspect USB sticks that don't appear to be data storage devices would be ignored. (I also once carried a bunch of Word documents on an SD chip in a camera, not for cloak and dagger reasons but just to have one less thing to lose.)
The third best prevention is to convince yourself that an officer searching your laptop is searching for:
- contraband data itself, most notably child pornography
- proof that your story of where you have been or where you are going (and why) is true or not
- proof of your immediate future plans or immediate past activity
- names and contact information of people who can confirm your story or who can be investigated as part of your criminal behaviour
They are not particularly searching for hot stock tips or the news that your company is considering acquiring another, nor the proprietary results of the latest tests on something you're developing. That information may have tremendous value to someone, but a rogue or corrupt customs official is probably more interested in celebrity photographs than corporate intelligence. But if you can't shake your fears, then keep the data off the laptop and if possible entirely off your person as you cross the border.
The best practice is not to keep sensitive and/or business critical data in a portable computer or device. The hard drive could fail anytime, the computer would be lost, broken, stolen. The best scenario is to host the data on any secure counter or server, which would be accessed either thought a VPN as @BurhanKhalid suggested or to be put somewhere in the Cloud and to be accessed from authorized devices only. I hope that this helps.