Patent ID: 7430294

Claim:
A method of recording user information on a storage medium for preventing unauthorized readout of the user information comprising: converting the user information into digital data; dividing the digital data into first and second data sets for recording on, respectively, optical and holographic storage layers of a storage medium, wherein a part of the user information is contained only in the first data set and another, remaining part of the user information is contained only in the second data set, wherein a ratio of the part to the remaining part is between a ratio of data capacities and a ratio of data reading speeds of the optical and holographic storage layers, and wherein information contained in any one of the first and second data sets is insufficient by itself to restore completely the user information contained in both the first and second data sets; recording the first data set on the optical storage layer of the storage medium; and recording the second data set on the holographic storage layer of the storage medium.