Transparently encrypt and mount an external drive in Windows

Question

I'm looking for a way to encrypt an external drive under Windows 7 Professional. I want something that works as transparently as possible. In particular, I don't want to mount it and enter password each time. Is there any program that mounts an encrypted volume based on Windows credentials, that is, when I log in to my account?

Answer 1

You can use TrueCrypt to set up the external drive a virtual encrypted disk within a file.

Since you do not want to enter a password, use instead a keyfile, together with the truecryptautomount project :

This project provides a windows script host JScript which allows using TrueCrypt key file encrypted drives to be automatically and transparently mounted when a USB stick with the correct key file is inserted.

Answer 2

BitLocker To Go can be used to encrypt external hard drives, and the authentication can be linked to the Windows user account:

You can optionally choose to automatically unlock a BitLocker To Go protected disk on a per-PC basis. This is reasonably safe if you provide a password when you logon to your PC and is certainly more convenient than retyping your device password every time you plug it in. If you do enable this option, it will not affect how BitLocker To Go functions on other PCs. (That is, the drive is still protected.)

Windows 7 Ultimate or Enterprise is required.