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So how does Microsoft propose to prevent this sort of abuse? Their answer,
simply put, is "trust us." Microsoft has proposed a code-signing system
called Authenticode which allows developers to embed a digital signature in
their ActiveX programs. This signature is then certified by an authority
such as VeriSign and cannot be altered without detection.
Assuming software authors provide VeriSign with accurate information,
Authenticode ensures that ActiveX controls can be traced back to their
authors. If signed software damages your system or deletes your data,
you'll likely know where to go for recourse. Such accountability will
probably deter many virus authors, but accountability is not security.
Authenticode completely sidesteps the real security and privacy issues at
stake. Authenticode provides no assurance that a program will not damage
your system and provides the user with no information about what the
software will actually do. Furthermore, since signed code may be
downloaded and executed automatically, there may be no way to even know
that an ActiveX control is running on your machine.
ActiveX will allow software companies to check for and delete unregistered
copies of their software from your machine or to alter your system
registry to cripple software published by their competition. Tax
authorities could retrieve your Quicken files and compare them with your
tax returns. And with a bit of careful programming, all this could be done
without your knowledge.
A well written control would leave no trace of itself, and would have to
be "caught in the act" to be traced by it's VeriSign signature. However,
even if you are able to track down the person who stole next quarter's
business projections, the damage has already been done. In this sense
Authenticode provides no security at all. Security is not about catching
the thief, but preventing the theft.
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