US Patent 11843690 Derived unique key per raindrop (DUKPR)

A method for a key management server to manage encryption for data stored by a cloud provider server includes receiving, by the key management server from the cloud provider server, a request for a drop key. The request includes a hash drop identifier that uniquely identifies a cipher drop, and the cipher drop comprises a unit of data stored by the cloud provider server. The method further includes generating the drop key based on at least the hash drop and the drop identifier and encrypting the drop key. A response comprising the encrypted drop key is sent to the cloud provider server.