What is a .snk for?

Question

What is a .snk file for? I know it stands for Strongly Named Key, but all explanations of what it is and how it works goes over my head.

Is there a

Answer 1

An .snk file is used to ensure that someone else can't slip an assembly of their own in the place of yours. It provides a pair of encryption/decryption keys.

When an .snk file is used to sign an assembly, a hashcode value is calculated from the assembly file and encrypted using the private key. That encrypted "digest" is then tacked on to the assembly together with the public key from the .snk file.

Then when someone receives your assembly, they can also calculate that hashcode value. They use the public key to decrypt the one that you calculated and compare the calculated values. If the assembly had been changed at all, those values will be different and the user of the assembly will know that the assembly you have is not the one you provided.

In the context of BizTalk Server, whoever builds any custom assemblies that are used by your BizTalk solution will need to use a .snk file to sign the assembly so that BizTalk server can load it into the GAC and use it.