Summary There are a few blog posts about using NServiceBus and encrypting strings using the WireEncryptedString type. However, you can also mark an ordinary string to be encrypted via configuration, which is more desirable as you can remove the dependancy from NServiceBus from your common Messages library. There is a gotcha though, if you ever mix the two, then WireEncryptedString go back to being unencrypted in MSMQ. This blog post explains how to easily fix this, and also how to remove NServiceBus from your Messages library. Win Win. Source code is avilable here . Compiling the project will automatically download packages via NuGet. Initial project setup Always have a separate Messages project to keep your messages in. In this example, the project is called Messages and contains the following class: using NServiceBus ; namespace Messages { public class MyMessage : IMessage { ...