Patent attributes
Techniques are disclosed for securing data in a cloud storage. Plaintext files are stored as secured, encrypted files in the cloud. The ciphering scheme employs per-block authenticated encryption and decryption. A unique file-key is used to encrypt each file. The file-key is wrapped by authenticated encryption in a wrapping-key that may be shared between files. A centralized security policy contains policy definitions which determine which files will share the wrapping-key. Wrapping-keys are stored in a KMIP compliant key manager which may be backed by a hardware security module (HSM). File metadata is further protected by a keyed-hash message authentication code (HMAC). A policy engine along with administrative tools enforce the security policy which also remains encrypted in the system.