IB  Ingrid Bergman in the 1944 film “Gaslight”

“…the Stasi often used a method which was really diabolic. It was called Zersetzung (gaslighting). The word is difficult to translate because it literally means “decomposition.”  But actually, it’s a quite accurate description. The goal was to secretly destroy the self-confidence of people, for example by damaging their reputation, by organizing failures in their work, and by destroying their personal relationships. Considering this, East Germany was a very modern dictatorship. The Stasi didn’t try to arrest every dissident. It preferred to paralyze them, and it could do so because it had access to so much personal information and to so many institutions.”
—Hubertus Knabe, German historian

One of the problems with en masse surveillance is that gives a government the power to psychologically attack anyone whom they do not like.  This has happened before, and it is happening now in some places. The STASI perfected gaslighting, and this perfection was based on their eavesdropping against the population.

A Sample Table of Trigraphs and Meanings

Sample Trigraph Code Table

Using bigraphs or trigraphs can offer a high level of privacy.  Use bigraphs for brevity.  Trigraphs are usually used when your code table is long, but this is not always the case.

Sending code messages like this can be done via Vernam Cipher (one time pad).  See the STASI “TAPIR” with its indicator for sending code (“84”).  In this example we will send a trigraph message encrypted with a one time pad (OTP) for optimal privacy.

For example:

Your message:  protest meeting success, being watched at this location, do not contact

Or:                       XBC XIO GGG EEE QQQ

Header:       YKX

Header +  Your message:         YKX XBC XIO GGG EEE QQQ

Encoded with the STASI (Ministerium für Staatssicherheit) code table “TAPIR”



___plain text ____________78617 78377 50528 37726 48357 57578 31118 36868 6883


     key                                          13698 93797 05536 49550 66877 17941 11148 70355 75933 94896


____cipher text___________81205 61064 55054 76276 04124 64419 42256 06113 3376

Notice the Modulo 10 system of addition (one adds without carrying over)

You and your corespondent both have the one time pad key, and you both have the same code table (TAPIR in this case) and the Trigraph table.  In this message we did not indicate that it would be code.  But one could do that easily by inserting “84” after the header (prior to encryption).  In this case both corespondents already knew that the trigraph code table would be used.  The benefit of this system is that the message is not going to be broken by computational attack, and that the string of numbers in the ciphertext (in the message one will send) can be hidden.  The header (YKX) indicates which key to use, and successive headers should not be sequential.