What you'll need is software for encrypting the data, and that software has to be portable, in that it runs on any PC without installation, since it will likely run from the flash drive itself.

But if you're crazy enough to trust your most important, irreplaceable data to a device that's even easier to misplace or forget than your keys, at least make sure that data is secure. It's unlikely to be the only copy-this is the age of online backup and sync, after all. There could be work documents, private pictures, your kid's birthday party video, or amazing notes for a NaNoWriMo novel-anything-on that drive. If you're the victim of such a theft, panic is understandable. It's not hard to lose a USB flash drive it's even easier to steal one. How to Set Up Two-Factor Authentication.How to Record the Screen on Your Windows PC or Mac.How to Convert YouTube Videos to MP3 Files.How to Save Money on Your Cell Phone Bill.

How to Free Up Space on Your iPhone or iPad.

How to Block Robotexts and Spam Messages.

Encrypting external drive