There are a number of vSphere Security enhancements that were introduced in vSphere 6.5 including the much anticipated VM Encryption feature. To be able to use the new VM Encryption feature, you will need to first setup a Key Management Interoperability Protocol (KMIP) Server if you do not already have one and associate it with your vCenter Server. There are plenty of 3rd party vendors who provide KMIP solutions that interoperate with the new VM Encryption feature, but it usually can take some time to get access to product evaluations.
During the vSphere Beta, VMware had provided a sample KMIP Server Virtual Appliance based on PyKMIP, which allowed customers to quickly try out the new VM Encryption feature. Many of you have expressed interest in getting access to this appliance for quick evaluational purposes and the team is currently working on providing an updated version of the appliance for customers to access. In the mean time, for those who can not wait for the appliance or would like an alternative way of quickly standing up a sample KMIP Server, I have created a tiny (163 MB) Docker Container which can be easily spun up to provide the KMIP services. I haver published the Docker Container on Docker Hub at lamw/vmwkmip. The beauty of the Docker Container is you do not need to deploy another VM and for resource constrained lab environments or quick demo purposes, you could even run it directly on the vCenter Server Appliance (VCSA) as shown here, obviously not recommended for production use.
The Docker Container bundles the exact same version of PyKMIP that will be included in the virtual appliance, this is just another consumption mechanism. It is also very important to note that you should NOT be using this for any production workloads or any VMs that you care about. For actual production deployments of VM Encryption, you should be leveraging a production grade KMIP Server as PyKMIP stores the encryption keys in memory and will be lost upon a restart. This will also be true even for the virtual appliance, so this is really for quick evaluational purposes.
Note: The version of PyKMIP is a modified version and VMware plans to re-contribute their changes back to the PyKMIP open-source project so others can also benefit.
Below are the instructions on using the KMIP Server Docker Container and how to configure it with your vCenter Server. I will assume you have worked with Docker before, if you have not, please have a look at Docker online resources before continue further or wait for the virtual appliance to be posted.