Question about stuxnet

Community
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This is a sophisticated multi-vector virus designed to exploit many weaknesses, and even the controllers (these do not run Windows). Because they knew the controlling computers did not connect to the internet, they embedded their own communication schemes. And they had access to the correct controller hardware and revs and compromised signatures. Wow.

Stuxnet: A possible attack scenario | ZDNet
May you explain more about this:

controller hardware and revs and compromised signatures

What are compromised signatures?

What does it mean?
they embedded their own communication schemes.

Pleas explain more.

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It can mean a lot of things.
Search engines are your friend, use them.

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Again digital signature is stolen from Taiwan, For sun of Stuxnet:

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