A data processing system and method to produce soft-copy book readers which are limited to reading only books published by a specific publisher

摘要

A data processing system method and program are disclosed for limiting a book reading program for softcopy books, to be capable of reading only softcopy books published by a selected publisher. The method includes the step of generating with a data processor, a customized polynomial expression to be associated with a selected softcopy book publisher. The method continues by merging with a data processor, the customized polynomial expression with a first shell program, forming a stamping tool program for stamping a key value onto a softcopy book published by the selected publisher. The key value results from the polynomial, using the product of an integer times a hash value of the publisher's identity, as the value of the independent variable. Then the method continues by generating with a data processor, a customized inverse polynomial expression to the customized polynomial expression, to be associated with the selected softcopy book publisher. Finally, the method merges with a data processor, the customized inverse polynomial expression with a second shell program, forming a book validation program for validating the key value on the softcopy book published by the selected publisher and enabling a softcopy book reading program to read the softcopy book. If the key value read from the book by the validation program, is determined to be an integral multiple of the publisher's hash value, then the key is valid.