top | item 45231071

(no title)

gsliepen | 5 months ago

The Intel architecture is already Turing complete when you just use MOV instructions: https://github.com/xoreaxeaxeax/movfuscator. Of course, you don't even need instructions at all: https://news.ycombinator.com/item?id=5261598

discuss

order

QuadmasterXLII|5 months ago

While this is true, I suspect a spec compliant implementation of the x86 mov instruction would many use more transistors than OP’s entire CPU.

crest|5 months ago

Of course, but you don't have the toy CPU under your desk or in your laptop running at several GHz nor are you likely to find it in a target that really needs a cute hack to obscure your exploit.

aleph_minus_one|5 months ago

> The Intel architecture is already Turing complete when you just use MOV instructions

No physically existing architecture is Turing-complete, since every CPU can (by physics) only access a finite amount of memory, which means that its state space is finite, in opposite to the infinite state space of a Turing machine.

jdiff|5 months ago

But that's not a very useful definition so we usually don't both enforcing that constraint.