The invention discloses an improved structure of light-source module, which arranges a reflection piece of light-source module in an image picking-up device of optical scanner. One disclosed method for asymmetrical encryption includes determining a ciphertext control block from data, where the ciphertext control block is based at least in part on one or more Chebyshev polynomials. The system further includes release coefficient database storing weight ratio data in each transfer and release destination per the identified management required substance in a form of database. The projection modification process converts the original image into a modified image according to the position information of the barcode. An output unit 28 reads the metadata of content and generates display data for displaying in timeline.