It looks like they had the US Govt SSL keys and certificates, as well as for other govts.
Pretty sure Maxwell's sister was involved, but don't quote me on that.
from Wiki:
In April 2002, Entrust's public key infrastructure technology served as the foundation for the prototype of what is now the United States Federal Bridge Certification Authority. The authority is an element of the trust infrastructure that provides the basis for intergovernmental and cross-governmental secure communications.[7]