OpenSparc -- the open source chip (except for the crypto parts)

[Ben Laurie]

Perry E. Metzger wrote:
> Marcos el Ruptor <ruptor at cryptolib.com> writes:
>>> To be sure that implementation does not contain back-doors, one needs
>>> not only some source code but also a proof that the source code one
>>> has is the source of the implementation.
>> Nonsense. Total nonsense. A half-decent reverse engineer does not
>> need the source code and can easily determine the exact operation of
>> all the security-related components from the compiled executables,
>> extracted ROM/EPROM code or reversed FPGA/ASIC layout
> 
> I'm glad to know that you have managed to disprove Rice's
> Theorem. Could you explain to us how you did it? I suspect there's an
> ACM Turing Award awaiting you.
> 
> Being slightly less sarcastic for the moment, I'm sure that a good
> reverse engineer can figure out approximately what a program does by
> looking at the binaries and approximately what an ASIC does given
> good equipment to get the layout. What you can't do, full stop, is
> know that there are no unexpected security related behaviors in the
> hardware or software. That's just not possible.

I think that's blatantly untrue. For example, if I look at an AND gate, 
I can be absolutely sure about its security properties.

Rice's theorem says you can't _always_ solve this problem. It says 
nothing about figuring out special cases.

Cheers,

Ben.

-- 
http://www.apache-ssl.org/ben.html           http://www.links.org/

"There is no limit to what a man can do or how far he can go if he
doesn't mind who gets the credit." - Robert Woodruff

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