We use a very similar system at work when placing files on removable media. Normally, any files you move from a work PC to a flashdrive are encrypted and cannot be decrypted unless the drive is put into another work PC running the same security software. However there's a feature of the software that still lets you move files to off-network PCs that works just like this. Your files are encrypted like usual but you can use your own password and there's now an html file included that contains all of the necessary crypto libraries. You open the html file on the other PC, type in the password, and it decrypts it for you and can re-encrypt it if you'd like.