A multi-tenant computer system authenticates access to a shared datastore by a shared service running on the multi-tenant computer system. The shared service is operable to access the shared datastore to execute requests from a plurality of multi-tenant cloud computing services. The requests include an indication of a particular tenant and a particular tenant grouping indicator. Requests are authenticated by cryptographically verifying the request and verifying that the particular tenant is associated with the particular tenant grouping indicator. In response to authenticating a request, the shared service accesses the shared datastore to execute the first request.