GB2468862A

GB2468862A - A method of protecting electronic content by encryption or deletion of consumed portions

Info

Publication number: GB2468862A
Application number: GB0904966A
Authority: GB
Inventors: Steven John Kennedy
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-24
Filing date: 2009-03-24
Publication date: 2010-09-29
Also published as: GB0904966D0; WO2010109237A1

Abstract

A data item is consumed in sequence from start to finish and a pointer is maintained to show how much of the data item has been consumed, The data item may be an electronic representation of a book or may be an audio or audio-visual item. Portions of the data item that have already been consumed are made inaccessible or are degraded, preferably by deleting or encrypting them. Consumed portions may be deleted or encrypted if they exceed a threshold from the pointer and, if the data item represents a book, the threshold may correspond to a predetermined number of words, pages or chapters. Preferably the data item is provided in an encrypted form — although a current region may be unencrypted — and an encryption key associated with a user or user device is required to decrypt the data. Typically, the invention finds application in protecting a pay per read (PPR) or one-read electronic book.

Description

A METHOD OF AND APPARATUS FOR PROTECTING A DATA ITEM

FurLu OF THE INVENS1ON The present InventIon relates to a med od of and apparatus for proteeting a data ttem, and to a computer program fOr implementing the method on a programmable data processor.

BACKtjROt.JNm) OFT' tiE IN VENT1ON Music and films have moved into the digital age where such audio and video items are available for download. This has simplified distribution but has. made illegal copying more prevalcr:t. Books had not made such a mass transition due to the intimate nature of the. reading exocrience. However recently electronic readers, for example the SONY reader have become available which marry the convenience ol electronic &iownioad with a hook like reading experience.

S't_JMMAKY (F'FiTF, iNvEN'rION According to a first aspect of'le present invention there is provided a method of protecting a data item wicre, in usc, th.e data item is consumed. in a. sequence progressing from a start to a finish, and wherein a pointer is maintained to show how much of the data item has been consumed, and wherein portions of the data item which have already been consumed are processed to make them tna.cccssb le or to degrade diem.

Thus a user can consume the data item. if the data. item is a book, then "consumed" relates to reading, whereas fOr music and video "consumed" relates to listening and watching, respectively.

Iti.s thus possbic to provtdc a process by which a piece of' digitalized copy is encrypted into a. town, that can be downloaded onto a dcvtce that decrypts the copy allowing it to be read a predetermined number of' times (usually once) the copy is then degraded as

I

described below in order to protect it from reuse or reproduction.

According to a seconñ aspect of the present invention there is provided a computer program for causing a programmable data processor to operate in accordance with the method of the tirst aspect of the present invention.

According to a third aspect of the present invention there is provided a data processor and display device arranged to allow a user to consume a data item rcprcsentng a book, audio or audiovisual presentation, wherein the data processor is adapted to degrade portions of the data item that have already been consumed.

seri 2t io of a,rcf ei'rcd embo diment of he inscnt 10 in a preferred embodiment a digital data item representing, for example., a hook, is held or a merchant's sen'er and is available for patd download as a. one read hook. The "One read hook" is an cnerypte.d hook that is designed to he read once in its entirety roughly hum beginning to end.

in use, a use.r may enter the merchants website. and select a hook for download. Th server constructs a. one read book, I rbook, from a master copy of the book that is retained on a secure server. f he IrBook may only he decrypted by-a single. target reader and may only be read through a limited number of times (typically once) on thai-target reader.

f he IrBook may, for example, be held in any proprietary or ope.n source format so long as that fonriat allows the book to he held as a series of chscretc drunks (such as sections, chapters, pages or lines) and includes the necessary software for the presentation of and nav1gation of those chunks on the target reader.

in use the reader device keeps a pointer, which in the context of a one read hook can be thought of as a hookmark. and which is a. data. structure that idcntfes the readers current place in the hook.

The irRook may Rave embedded data dentfyig the number of times the hook may he read (typically once, the chunks kept behind the bookmark (i.e. portions which have already been read or consumed" and the number ol chunks decrypted ahead ot the bookmark. The unencrvpted chunks arc inferred to as the currenf chunks and the reader of the hook may view these at wilL This allows fiexibtljt on a per I rHook basis in die amount oflook ahead2 and look back2 that a reader is permitted when reading through the rBook.

The lrBook is, in use, read like any other eBook. When the reader passes a chunk boundary (by whatever means typically seroilng or selcel-ing "Next page'° or some such), chunks that have been read are deleted or reencrypted, This processing causes those portions which have been consumed to he made inaccessible, Similarly chunks that are yet to he read arc decrypted as necessary to ensure that the correct range of chunks are current.

Ii the reader aRcmnpts to access an encrypted ctiunk they may be provided wuli a "Uan1t read" page that may be specified witlu the irBook, The contents of this page would tzpicaily include options t) iiuchase another pay per read,PPR. of the book, a fid I electronic copy of the book, orto order a physical copy of the hook. A different page may opIonaily be presented fbr chunks already read and br chunks that have not vet Deen read.

Pay per read P11t advantageously uses a dual key encrypted exchange of inlormanon between tne supplier and the reader, Tnts assures that only the authorized reader can decrypt the trBook.

When the book is opened for reading, it is decrypted using the secret key associated with the reader. Such a key may be held in memor that is not normally accessible to users.

This encryption layer is distinct from the encryption used within the lrBook and does not consttutc part ot' this specifIcation although the reader public key is likely to be used by the encryption used within the IrBook to avoid unnecessary key generation.

Once the rBook is opened for reading. the bookmark key associated with the rBook decrypts the chunks of the hook that the bookmark identifies as current. The bookmark is protected such that it may be incremented bitt cannot be dccrerncnicd, or rot dccrcmentcd without a secure key, so the hook can be read in its entirety only once by the reader. If the book nay be read rnore'han once then ii is possiNe'o reset the bookmark to permit the specified number of reads after which the reset operation will fad displaying: the Cant rea& page (and in any event the material will have been deleted).

It is thus possible to provide a method of protecting electronic hooks from copying or 1mm unauthorized iiinltiple accesses.

Although the invention has been described in the context of a hook, it can he applied to any data kern, such as music or video.

Claims

CLAIMSA method of protecting a data item where, iii use, the data item is consumed in a sequence progressug hum a start to a finish, and wherein pOinter is maintained to show how much of the data item has been consumed, and wherein portions of the data item whrch have aLready been consumed are processed to make them inaccessible or to degrade them.
2 A method as clatmed in claim 1, in which portions that have been consumed by a user are deleted or encrypted.
A methoa as clanned in claim 2, in w!ucn poilioris that exceea a trst threshold from the pointe.r are deleted or encrypted.
4 A method as claimed in claim 3. in which when the data item represents a book, the first threshold corresponds to a predetermined number of words, pages or chapters.
A method as claimed in any of the preceding claims, in which the data. item is provtded in an encrypted form, and the encryption key associated with a user or a user device is recuirec1 to decrypt the dala item.
6 A method as claimed in any of the preceding claims in which a portion of the data item representing a "current region" is kept in unencrypted ibrm.
7 A method as claimed in any of the preceding claims in which the. data item is an electrouc representation of a book.
8 A method as claimed in any of the preceding claims in which the. data item is an audio or audiovisua item 9 A computer rograni for causing a programmable data proces.sor to operate in accordance with the method of any of claims ito 8.if) A data processor and dtspiay device arranged to allow a user to consume a dala item representing a hook, audio or audiovisua presentation, wherein the data rocessor is adapted to degrade portions of the data item wheh have airead been consumed.