Guidance on storing sensitive data on an external disk or USB pen

• You should choose one of the following approaches :-
  1. encrypt the whole device using a tool such as FileVault (MacOS),TrueCrypt (Windows), gnome-disk-utility (Linux) or VeraCrypt (Linux)
  2. store sensitive data on an encrypted volume on the device using the same tools as above.

Issues

• When storing sensitive data on an encrypted disk or USB key, be aware that many applications will store temporary unencrypted copies of that data in application temporary directories on the machine from which you are accessing the device. You can reduce this risk by frequently running a tool such as the Windows disk cleaner utility.

See also the University's guidance on encryption.