Mindlock
From Lexicanum
A mindlock is a technique used by sanctioned psykers of the Imperium. Per orders of the commanding officials, a mindlock can be place upon a person to secure important secrets that person knows. A mindlock is similar to encrypting data, and can be unlocked later by those who had mindlock him or her in the first place.
To date, there has been only one known individual who has been mindlocked, Noches Sturm1, former Lord General and ex-commanding officer Royal Volpone Imperial Guard regiments (aka the "Blue Bloods"). While under the effects of the mindlock, Sturm possessed no former knowledge of his old life, nor his personality.
Mindlocks can be broken given time and psyker intervention, however.1
The Imperium may not be the only race who makes use of the psyker techniques of mindlocking, or at least combining aspects of it. The Eldar made use of a form of mind control over a prominent Inquisitor. The purpose of this was to secure the Corona Nox, a powerful artifact entrusted to traitor Space Marine Zso Sahaal almost 10,000 years before current events.2
Other Usage
The term "mindlock" is also used to refer to the tendency of servitors' brains to freeze up in combat situations without active direction from a techpriest or techmarine.3
Trivia
Mindlocks seem to be a psychic based reference to cryptology, a means of communicating orders that was extensively used during World War II. Cryptology is still used today for electric data encryption in almost all fields, and is the basis of much of today's electronic security.
