Patent ID: 9465947
Filing Date: 2016-10-11
CPC Classification: G06F,H04L

Claim Text:
1. A cloud storage system, comprising: an encryption server configured to encrypt a plurality of data by using encryption keys having a hierarchy, the hierarchy of encryption keys corresponding to a relationship among the plurality of encrypted data; and a cloud storage server configured to store the plurality of encrypted data, wherein at least two or more data are configured in a directory structure, the hierarchy of the encryption keys corresponding to the directory structure, wherein the encryption keys are generated in a stateless manner based on key derivation information received by the encryption server, the key derivation information comprising information about a key derivation function, the key derivation function configured to determine an encryption key based on a root key and a directory path, the root key being a key at a top of the hierarchy of the encryption keys, and wherein at least one of the encryption server and the cloud storage server is implemented by at least one hardware processor.