Living Software

Living Computation

Adapted from Ackley (1996)

Managing distributed computations across large networks of separately administered resources is in important ways more akin to managing a human society than to marshalling the closely-held resources of a single digital computer. The Von Neumann architecture simply will not extend to an effective basis for large-scale distributed computing. Viewing living systems, especially living ecosystems, as computational systems, provides many insights into what the successful architecture will look like. In many ways the object-oriented programming approach is an important step in the right direction, but at the same time, fundamental issues---most quite obvious in the context of living systems---remain largely unrecognized.

Sense of self

Consider, for example: Relatively ``complex'' living organisms such as, say, mammals, are always ``designed, built, and tested'' on a whole system basis---there are never any ``plug-ins,'' ``patches,'' or ``upgrades'' to an individual's genetic code (at least, not until very recently). The mechanisms for storing and transmitting the germ line code defend against external alterations in many ways---physical, chemical, biochemical, developmental, immunological, instinctive, and cultural. Such elaborate and expensive defenses may be explained by the relatively high cost of producing a system. If the results could be easily ``hijacked,'' the capital investment would be unwarranted.

On the other hand, relatively ``simple'' living organisms such as bacteria are capable of incorporating ``stray'' bits of external code from their environment into their ``operating systems''---as when a gene coding for drug resistance is observed to ``jump species''---to the dismay, at least, of the complex organisms that produce the drug. Such promiscuity may be explained by the relatively low cost of producing a system combined with the potential gains to be had by ``stealing code.''

Is a computer system more like a collie or an E. Coli? On the one hand, even a personal computer is an expensive investment, and if it is used productively its value rises much higher than its capital cost. On the other hand, personal computers today are a motley patchwork of code from dozens of sources, with essentially no ``sense of self'' (for an exception, see, e.g., Forrest, 1996), and only the most rudimentary and shallow of defenses.

In the long run, we can be quite confident that this embarrassing combination of traits will not persist---in the language of evolutionary biology, it is not an ``evolutionarily stable strategy.'' (Maynard Smith, 1982). The essentially immediate explosion of computer viruses following the rise of personal computers is testament to this. Viewed in evolutionary terms, it makes no more sense to rail at the immorality of the virus writers that exploited the situation than it does to blame the system developers that created it. In both cases the protagonists were simply exploiting an opportunity that existed in the environment of the time. Personal computer manufacturers could cut costs by eliminating even the most basic immunologic mechanisms such as protected kernel mode and rationalize the decision by observing that computer viruses were not currently much of a problem. At the time, it was plausible to claim that these are ``personal'' computers that won't be networked like more expensive systems. On the flip side, virus writers and other attackers immediately exploited the results, rationalizing their behavior, where they felt the need to, by observing that they were just revealing obvious design problems that could easily be exploited for gain, and which the cheap-skate manufacturers are papering over about rather than fixing.

Loyalty and ``personal'' computing

Today, the appellation ``personal computer'' is in important ways a misnomer. Although individually owned, the personal computer does not ``know'' its owner in any significant way, and that's just as well because it is fundamentally unable to distinguish between what is ``inside itself'' and to be trusted with sensitive information (merely beginning with passwords) and what is not. If future personal computers do not make a strong and credible case for loyalty to their owners, all the graphical interface and ease-of-use improvements in the world will not get people to use them for serious work. On the other hand, if a system demonstrates that is manifestly watching out for its owner's best interests, first, last, and always, from hardware to software to data and communications, people would be willing to clap rocks together in Morse code to interact with it.

References

Ackley, D. H. (1996, to appear).: ccr: A Network of Worlds for Research. In Artificial Life V, MIT Press.
Forrest, S., Hofmeyr, S.A., Somayaji, A., and Longstaff, T.A. (1996, in press).: A sense of self for Unix processes. In the 1996 IEEE Symposium on Computer Security and Privacy.
Maynard Smith, J. (1982).: Evolution and the theory of games. Cambridge University Press: Cambridge.