Computing has a nice analogy in lasers. When lasers (and masers) were first built it was extremely hard to make one. Lots of engineering and design went into getting something to properly lase. Then, over time it became easier once the principles were understood. Later still it was realized that given the right conditions you could get a very large number of substances to lase, some of them even accidental.
In the long turn it will possibly be found that it is harder to have tech of any sufficient complexity that can not be used for general purpose computation than stuff that can be used that way. To find another computer inside an existing computer that was placed there accidentally is perhaps less of a surprise if you look at it that way.
Other candidates: sufficiently large chunks of a network, hydraulics systems, power infrastructure, biological systems.
Could someone explain this in a way that a middling-experienced high-level coder can understand? It's clearly awesome, but I'd like to get it a bit better than I do.
1. The author demonstrates that page faults on the IA32
architecture are Turing complete. Or more precisely,
the automatic memory caching, address translating,
interrupt handling, etc, which the CPU does behind the
curtains while executing programs.
2. This means that if you carefully arrange the contents
of memory, you can write "programs" that don't have any
instructions.
3. This has implications for various sorts of (static?)
analysis which people do on programs. For instance,
you might analyze a program as a series of
instructions, and think it does one thing, when the
above side-channel is actually doing another thing.
In the long turn it will possibly be found that it is harder to have tech of any sufficient complexity that can not be used for general purpose computation than stuff that can be used that way. To find another computer inside an existing computer that was placed there accidentally is perhaps less of a surprise if you look at it that way.
Other candidates: sufficiently large chunks of a network, hydraulics systems, power infrastructure, biological systems.