Communication terminal, portable terminal, circulating server, providing server, electronic book distributing method, and eletronic book distributing program

Abstract

A portable terminal according to the present invention is provided with an electronic book coupon storage, a book data receiver, an electronic book coupon deductor, and a book data decryptor. The electronic book coupon storage stores an electronic book coupon used in acquisition of book data containing a plurality of page data units, along with a decryption key used in decryption of the plurality of page data units. The book data receiver receives the book data from an electronic book providing server. The electronic book coupon deductor deducts an electronic worth equivalent to a price according to page data requested to be read out, from the electronic book coupon. The book data decryptor decrypts the page data in steps of one page data unit by use of the decryption key in conjunction with the deduction of the electronic worth.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of U.S. application Ser. No. 10 / 441,162 filed on May 20, 2003, which claims priority to Japanese Patent Application No. 2002-145037 filed on May 20, 2002 and Japanese Patent Application No. 2002-145045 filed on May 20, 2002. The contents of each of these documents are incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to a communication terminal, a portable terminal, a circulating server, a providing server, an electronic book distributing method, and an electronic book distributing program. [0004] 2. Related Background Art [0005] In recent years, electronic books (also called e-books (trademark)), which are superior in portability and searchability to books of paper media and which can contain records of sound, are in practical use. The electronic books are digitized books which can be purchased and read by use of such termi...

AI Technical Summary

Benefits of technology

[0008] In view of the above problem, an object of the present invention is therefore to provide a communication terminal, a portable terminal, a circulating server, a providing server, an electronic book distributing method, and an electronic book distributing program permitting acquisition of an electronic book in component units and thereby achieving improved convenience in use of the electronic book.

[0116] According to the present invention, the key used in encryption of the book data is different from the key used in decryption of the book data. Namely, the public-key cryptographic scheme is adopted for the encryption and decryption of the book data. The public-key cryptographic scheme has lower degree of necessity for transmitting keys through a safe route and ensures easier management of keys with higher security than the private (common)-key cryptographic scheme. Accordingly, a higher security level can be ensured about the book data.

Problems solved by technology

In the above prior art, however, the electronic books were distributed in book units (volume units), and it was easy to collect royalties and sales fees according to the number of volumes sold; on the other hand there was the problem as described below.

Images