Patent ID: 8090106

Claim:
A multi-level data encryption method, comprising: dividing a data into a plurality of sub-data blocks according to a plurality of levels, wherein each of the levels is corresponding to at least one user; receiving a level generation key of each the level, a time generation key and a time seed from a data server by a wireless sensor, wherein the level generation key of each the level, the time generation key and the time seed are generated by the data server; generating a time key of each the level according to the time generation key and the time seed by the wireless sensor; generating an encryption key for each of the levels according to the level generation key and the time key of each the level by the wireless sensor; and respectively encrypting the sub-data blocks of the levels by using the encryption keys of the levels by the wireless sensor, wherein the level generation key and the time key of a lower level are generated according to the level generation key and the time key of an upper level, and the time seed is periodically updated by the data server according to different encryption periods.