When working in a high-risk environment, the safety of your data is absolutely crucial. A suitable solution to this issue could come from an advanced drive encryption tool; for instance, you can try StorageCrypt.
Being unfamiliar with this type of program won't be a problem, as the application will bring you the easiest way to password-protect and decrypt any drive. Basically, you need to follow four simple steps: select the drive you wish to encrypt, enter the proper password, choose the encryption mode and, if needed, opt for a partition encryption.
An aspect that I definitely didn't like about StorageCrypt was its inability to encrypt the current system boot disk where I keep important documents. Also, an annoying sound plays each time you encounter an error and you can't disable this option.
From my point of view, the application could have offered more settings or utilities like an option to notify me whenever a user is trying to access StorageCrypt or even the encrypted drives, a password generator, etc. As for its price, I think the application is quite affordable considering the fact that this type of programs mostly come as expensive.