What is a Strong Name?

A strong name consists of the assembly’s identity its simple text
name, version number, and culture information (if provided) plus a
public key and a digital signature. It is generated from an assembly
file (the file that contains the assembly manifest, which in turn
contains the names and hashes of all the files that make up the
assembly), using the corresponding private key. Assemblies with the
same strong name are expected to be identical.
Strong names guarantee name uniqueness by relying on unique key
pairs. No one can generate the same assembly name that you can,
because an assembly generated with one private key has a different
name than an assembly generated with another private key.
When you reference a strong-named assembly, you expect to get
certain benefits, such as versioning and naming protection. If the
strong-named assembly then references an assembly with a simple
name, which does not have these benefits, you lose the benefits you
would derive from using a strong-named assembly and revert to DLL
conflicts. Therefore, strong-named assemblies can only reference
other strong-named assemblies. There are two ways to sign an
assembly with a strong name:
1. Using the Assembly Linker (Al.exe) provided by the .NET Framework
SDK.
2. Using assembly attributes to insert the strong name information
in your code. You can use either the AssemblyKeyFileAttribute or the
AssemblyKeyNameAttribute, depending on where the key file to be used
is located.
To create and sign an assembly with a strong name using the Assembly
Linker, at the command prompt, type the following command:
al /out: /keyfile:
In this command, assembly name is the name of the assembly to sign
with a strong name, module name is the name of the code module used
to create the assembly, and file name is the name of the container
or file that contains the key pair.
The following example signs the assembly MyAssembly.dll with a
strong name using the key file sgKey.snk.
al /out:MyAssembly.dll MyModule.netmodule /keyfile:sgKey.snk
To sign an assembly with a strong name using attributes
In a code module, add the AssemblyKeyFileAttribute or the
AssemblyKeyNameAttribute, specifying the name of the file or
container that contains the key pair to use when signing the
assembly with a strong name. The following code example uses the
AssemblyKeyFileAttribute with a key file called sgKey.snk.
[Visual Basic]

[C#]
[assembly:AssemblyKeyFileAttribute(@"....sgKey.snk")]