US Patent 10083325 Secure removable storage for aircraft systems

Techniques are disclosed for securing backup operational data (e.g., of an aircraft) maintained by a line-replaceable unit (LRU) in a removable storage media device. The LRU generates a first encryption key. The LRU encrypts the operational data using the first encryption key. The LRU generates a second encryption key based on key data of at least a second LRU. The LRU encrypts the first encryption key using the second encryption key.