Uncrackability

So that although the Director may have been the anguished figure earlier described, distressed at having to sacrifice a handful of agents in order to save his country, it is equally possible that he was a stolid bureaucrat pinning his simple faith on the uncrackability of his codes.

The makers argue that foreign encryption software will rush in to fill the gap, doing nothing about the uncrackability problem – indeed, making it worse.

The uncrackability of one-time pads requires they must be completely random and never seen or used before or after.