1. A method comprising: receiving, by a first computing device, a request for credentials from an unauthenticated second computing device, said request including a machine identifier associated with the unauthenticated second computing device; issuing the credentials for association with the machine identifier; associating the issued credentials with the machine identifier; assigning a credential group identifier to the machine identifier; associating the issued credentials with the assigned credential group identifier; and associating the machine identifier and the credential group identifier with data operations associated with the unauthenticated second computing device to enable identification of the unauthenticated computing device as the source of the data operations, wherein the association among the credentials, the machine identifier, and the credential group identifier persists across communication sessions between the first computing device and the unauthenticated second computing device, and wherein the first computing device modifies the credential group identifier responsive to the issuance of additional credentials for the unauthenticated second computing device.