While trying to install print drivers for my HP 722C Deskjet (the saga continues), I got a strange error message. In brief, it says “Windows did not find a Microsoft signature assocaited with the software package you want to install.”
Ok, now could someone please translate this into plain English? What is a Microsoft signature? Like, do I need Bill Gates’ autograph, or what?
There are a variety of code-signing techniques. In general, they involve creating a cryptographic hash of the program and then digitally signing it with a public-key encryption algorithm. The installation routine then does something like the following:
see that the application purports to be from Microsoft
decrypt the signature with Microsoft’s public key. If it decrypts properly, then you know it actually came from Microsoft.
create a hash of the program and compare it to the hash in the signature. If they match, then you know the application has not been modified from the version Microsoft released.
Digital signatures are intended to solve two problems: the message (email, document, program) comes from who you think it come from, and it hasn’t been modified in between.