| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cipher recording medium which allows easy discrimination between the line portion and the background portion of a restored image when an original image is restored from encryption images, while using visual decryption type secret sharing scheme. <P>SOLUTION: Among information cells and blank cells constituting the encryption patterns of a plurality of encryption images generated by visual decryption type secret sharing scheme, the areas of information cells are expanded to provide an expanded portion 22. Accordingly, when obtaining the restored image by superposing the encryption images, the restored image can be viewed without the need of precise alignment. <P>COPYRIGHT: (C)2012,JPO&INPIT |
