If your application is signed with a strong name, Visual Studio will require you to sign every assembly you reference. Now, even if you are a .NET only developer, it happens sometimes that you have to deal with some kind of interop with C++/CLI DLLs. If both situations happen, you will find yourself in the need to sign a C++ assembly with a strong name.
To do so, you have to specify the key file you will use, at: Project-> Properties-> Configuration Properties-> Linker-> Advanced-> Key File. Something like this:
Don't try to sign the assembly with a .Pfx file. It won't work. To do so, you need a .SNK file (Strong Name Key). You can generate one with the SN.EXE tool, using:
sn.exe –k [directory]\[filename].snk
Where to find SN.EXE?
In the Microsoft .NET Framework SDK (usually c:\program files\microsoft .net\sdk\bin, or something similar). You can download the SDK from here.
Note: In order to install the SDK, you will also need the .NET Framework 1.1 installed. As it's a bit old, many people don't have it in their machines.
Inaki Ayucar is a Microsoft MVP in DirectX/XNA, and a software engineer involved in development since his first Spectrum 48k, in the year 1987. He is the founder and chief developer of The Simax Project (www.simaxvirt.com) and is very interested in DirectX/XNA, physics, game development, simulation, C++ and C#.
His blog is: http://graphicdna.blogspot.com
To contact Inaki: email@example.com