World War II Anecdote about Trust and Security

This is an interesting story from World War II about trust:

Jones notes that the Germans doubted their system because they knew the British could radio false orders to the German bombers with no trouble. As Jones recalls, "In fact we did not do this, but it seemed such an easy countermeasure that the German crews thought that we might, and they therefore began to be suspicious about the instructions that they received." The implications of this are perhaps obvious but worth stating nonetheless: a lack of trust can exist even if an adversary fails to exploit a weakness in the system. More importantly, this doubt can become a shadow adversary. According to Jones, "...it was not long before the crews found substance to their theory [that is, their doubt]." In support of this, he offers the anecdote of a German pilot who, returning to base after wandering off course, grumbled that "the British had given him a false order."

I think about this all the time with respect to our IT systems and the NSA. Even though we don't know which companies the NSA has compromised -- or by what means -- knowing that they could have compromised any of them is enough to make us mistrustful of all of them. This is going to make it hard for large companies like Google and Microsoft to get back the trust they lost. Even if they succeed in limiting government surveillance. Even if they succeed in improving their own internal security. The best they'll be able to say is: "We have secured ourselves from the NSA, except for the parts that we either don't know about or can't talk about."