US Patent 9904788 Redundant key management

A data storage service redundantly stores data and keys used to encrypt the data. Data objects are encrypted with first cryptographic keys. The first cryptographic keys are encrypted by second cryptographic keys. The first cryptographic keys and second cryptographic keys are redundantly stored in a data storage system to enable access of the data objects, such as to respond to requests to retrieve the data objects. The second cryptographic keys may be encrypted by third keys and redundantly stored in the event access to a second cryptographic key is lost.