VeraCrypt - Free Open source disk encryption with strong security for the Paranoid

Documentation Security Requirements and Precautions Physical Security

# Physical Security

If an attacker can physically access the computer hardware and you use it after the attacker has physically accessed it, then VeraCrypt may become unable to secure data on the computer.* This is because the attacker may modify the hardware or attach a malicious hardware component to it (such as a hardware keystroke logger) that will capture the password or encryption key (e.g. when you mount a VeraCrypt volume) or otherwise compromise the security of the computer. Therefore, you must not use VeraCrypt on a computer that an attacker has physically accessed. Furthermore, you must ensure that VeraCrypt (including its device driver) is not running when the attacker physically accesses the computer. Additional information pertaining to hardware attacks where the attacker has direct physical access is contained in the section Unencrypted Data in RAM.
Furthermore, even if the attacker cannot physically access the computer hardware directly, he or she may be able to breach the physical security of the computer by remotely intercepting and analyzing emanations from the computer hardware (including the monitor and cables). For example, intercepted emanations from the cable connecting the keyboard with the computer can reveal passwords you type. It is beyond the scope of this document to list all of the kinds of such attacks (sometimes called TEMPEST attacks) and all known ways to prevent them (such as shielding or radio jamming). It is your responsibility to prevent such attacks. If you do not, VeraCrypt may become unable to secure data on the computer.

* In this section (Physical Security), the phrase "data on the computer" means data on internal and external storage devices/media (including removable devices and network drives) connected to the computer.