diff --git a/dotnet/Directory.Build.props b/dotnet/Directory.Build.props
index 88c409e86..5198064b3 100644
--- a/dotnet/Directory.Build.props
+++ b/dotnet/Directory.Build.props
@@ -8,4 +8,9 @@
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
+  <PropertyGroup Condition="'$(MSBuildProjectName)' == 'GitHub.Copilot.SDK'">
+    <AssemblyOriginatorKeyFile>$(MSBuildThisFileDirectory)Open.snk</AssemblyOriginatorKeyFile>
+    <SignAssembly>true</SignAssembly>
+  </PropertyGroup>
+
 </Project>
diff --git a/dotnet/Open.snk b/dotnet/Open.snk
new file mode 100644
index 000000000..22a3cbd25
Binary files /dev/null and b/dotnet/Open.snk differ