  Matter, especially DNA, is now programmed to carry out useful processes at
the nanoscale. As these programs and processes become more complex and their
envisioned safety-critical applications approach deployment, it is essential to
develop methods for engineering trustworthiness into molecular programs. Some
of this can be achieved by adapting existing software engineering methods, but
molecular programming also presents new challenges that will require new
methods. This paper presents a method for dealing with one such challenge,
namely, the difficulty of ascertaining how robust a molecular program is to
perturbations of the relative "clock speeds" of its various reactions. The
method proposed here is game-theoretic. The robustness of a molecular program
is quantified in terms of its ability to win (achieve its original objective)
in games against other molecular programs that manipulate its relative clock
speeds. This game-theoretic approach is general enough to quantify the security
of a molecular program against malicious manipulations of its relative clock
speeds. However, this preliminary report focuses on games against nature, games
in which the molecular program's opponent perturbs clock speeds randomly
(indifferently) according to the probabilities inherent in chemical kinetics.
