4. The system of claim 1 , wherein the first entity is unaffiliated with the second entity, and wherein the signed fictitious document appears, to the first entity, to represent the second entity as one of the plurality of tenants.
1. A system for concealing tenancy in a multi-tenant cloud service relying on federated identities, said system comprising: a memory area associated with a cloud service, said memory area storing a set of tenant identifiers each corresponding to one of a plurality of tenants of the cloud service; and a processor programmed to: receive a request for a document from a first entity by the cloud service, the request including an identifier associated with a second entity; receive, from an identity provider, a token authenticating the first entity; compare the identifier to a set of tenant identifiers each corresponding to one of the plurality of tenants to determine whether the second entity is one of the plurality of tenants; dynamically generate a fictitious document in response to the request after determining that the second entity is not one of the plurality of tenants; digitally sign the generated fictitious document with a certificate for the second entity; and send the signed fictitious document to the first entity.