Shared Services Canada is the central.... It's sort of a procurement agency, but not because it lives on its own within Public Services and Procurement Canada. However, it is the arm of government that is used to supply IT services to line departments, including cloud computing services.
The second part of your question was about protected B documents. Protected B or medium-security data is a data classification system. Our services, for the purposes of the cloud framework agreement, were evaluated as to whether or not they provided sufficient security guardrails for that level of classified data.