Generating 56-bit passwords using Markov Models (and Charles Dickens)

We describe a password generation scheme based on Markov models built from English text (specifically, Charles Dickens *A Tale Of Two Cities*). We show a (linear-running-time) bijection between random bitstrings of any desired length and generated text, ensuring that all passwords are generated with equal probability. We observe that the generated passwords appear to strike a reasonable balance between memorability and security. Using the system, we get 56-bit passwords like The cusay is wither? t, rather than passwords like tQ$%Xc4Ef.