Patent Application
20140109234
1. Field of the Invention
The invention generally relates to the field of access control for data content in portable memory devices, and more particularly, to systems and methods for limiting the number of electronic devices accessing Digital Rights Management (DRM) content in a portable memory device.
2. Description of the Related Art
In recent years, there has been an exponential growth in the development of semiconductor memory technology and in the use of the Internet. Coupled with the advancements in computing technology, software programs, music, books, video games, and even full-length movies, have become widely available in high-quality, easily reproducible and easily transmitted digital formats. Correspondingly, various methods have been developed for preventing the spread of rampant piracy and unauthorized distribution, by controlling the access to the digital content which is usually carried in portable memory devices. Generally, the methods may be divided into the following groupings.
This method, as described in U.S. Pat. No. 5,592,651 by Rackman et al., requires a portable memory (generally refers to a Write-Many Read-Many (WMRM) memory) device with protected content to be additionally equipped with a Write-Once Read-Many (WORM) Memory chip in which the storage volume is exactly the size for storing a fixed number of Unique Identifications (UIDs) of electronic devices allowed to access the WORM memory chip. When the portable memory device is coupled to an electronic device, the software stored in the portable memory device is executed to compare the UID of the electronic device with the UIDs in the WORM memory chip. If a match is found, the software allows the electronic device to access the protected content in the portable memory device. Otherwise, if no match is found, the software attempts to write the UID of the electronic device into the WORM memory chip. The write attempt is granted and the electronic device is allowed to access the protected content, only if there's a space in the WORM memory chip for storing the UID of the electronic device.
However, this method has certain drawbacks. For instance, having a general portable memory device to be equipped with an additional WORM memory chip increases costs. Also, the complexity of packaging, connection layout designs, and microcontroller operations regarding the equipment of the additional WORM memory chip increases significantly.
According to the specifications of Digital Rights Management (DRM), a consumer may upload the UIDs of electronic devices for rightful use of protected content, during the process of issuing Rights Object (RO) by the Rights Management Module (RMM) in a DRM server. Thus, the uploaded UIDs form a specific domain for the registered electronic devices to be able to access protected content.
This method, however, requires the electronic device to be online in the network where the DRM server (also referred to as a backstage server) is located, so that the DRM server may check if the UID of the electronic device is within the specific domain. Unfavorably, this limitation creates inconvenience for consumers because one major feature of the portable memory device is that it may be used offline.
A portable memory device may be preloaded with a fixed number of ROs, and each RO may be used by the DRM agent in an electronic device only when it is moved to the electronic device, wherein each RO may be moved only once. In addition, the protected content is accessible under the condition in which the portable memory device is coupled to the electronic device. As a result, a consumer may move the RO(s) from the portable memory device to any electronic device in which the protected content is rightfully used, while the protected content may remain accessible to only one electronic device at a time. Thus, over licensing may be prevented. However, the implementation of this method has a rather high technical threshold, and allowing a consumer to move the RO(s) at will, may cause operational errors.
In one aspect of the invention, a system for managing access to DRM content is provided. The system comprises a portable memory device and an electronic device. The portable memory device comprises a public area for storing software and the DRM content, and a hidden area for storing data on predetermined addresses among all addresses in the hidden area. The electronic device is coupled to the portable memory device. The software is executed by the electronic device for obtaining a first identification associated with an electronic device in response to the portable memory device being coupled to the electronic device, and only allowing the electronic device to access the DRM content in response to the first identification being equal to the data on one of the predetermined addresses, or the first identification being different from the data on the predetermined addresses and the data on one of the predetermined addresses being equal to a predetermined number.
In another aspect of the invention, a method for managing access to DRM content is provided. The method comprises the steps of providing a portable memory device comprising a public area for storing the DRM content, and a hidden area for storing data on predetermined addresses among all addresses in the hidden area; obtaining a first identification associated with an electronic device in response to the portable memory device being coupled to the electronic device; and only allowing the electronic device to access the DRM content in response to the first identification being equal to the data on one of the predetermined addresses, or the first identification being different from the data on the predetermined addresses and the data on one of the predetermined addresses being equal to a predetermined number.
Other aspects and features of the invention will become apparent to those with ordinary skill in the art upon review of the following descriptions of specific embodiments of the systems and methods for managing access to DRM content.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
Note that, the shield area 23 is created and the UID of the portable memory device 100 is imprinted therein by the memory device company during the manufacturing process. In addition, the division of the public area 21 and the hidden area 22 is performed using an initialization firmware provided by the microcontroller company during an initialization procedure, so that the manufacturer of the portable memory device 100 may create and read/write the hidden area 22. For the convenience of the purchasing company, e.g., a digital content company, the manufacturer of the portable memory device 100 prepares a certain library/machine code for the purchasing company to be able to access the hidden area 22, while the shield area 23 remains accessible only via the custom firmware for reading purpose only. In other words, general consumers may not read/write data at will in the hidden area 22 and the shield area 23.
Before the portable memory device 100 is delivered to consumers, it may be further initialized by the digital content company with a series of processes as shown in
After that, when the portable memory device 100 is delivered to consumers and coupled to an electronic device, the NEDCS in the portable memory device 100 is executed by the electronic device for performing the method for managing access to DRM content as proposed in the invention.
In another embodiment for step S320, the algorithm may be applied to both of the UID(s) of the electronic device and the UID of the portable memory device 100 to generate the identification associated with the electronic device, and the NEDCS may read the UID of the portable memory device 100 from the shield area 23 by calling an Application Programming Interface (API) provided by the microcontroller company to invoke the microcontroller 10 to access the shield area 23 via the custom firmware provided by the microcontroller company.
Subsequently, the NEDCS compares the identification associated with the electronic device with the data on the specific addresses where the original null numbers were initially written (step S330). If a match is found, the electronic device is allowed to access the DRM content in the public area 21 (step S340). If no match is found and at least one of the original null numbers remains on the corresponding address, the electronic device is allowed to access the DRM content in the public area 21 and one of the original null numbers is replaced with the identification associated with the electronic device (step S350). Otherwise, if no match is found and the data on the specific addresses is no longer equal to any one of the original null numbers, then the electronic device is not allowed to access the DRM content in the public area 21 (step S360). Thus, the number of electronic devices accessing the DRM content may be limited.
To further clarify, the NEDCS is preconfigured, before it is compiled under a specific operating system, with the information concerning the library/machine code for accessing the hidden area 22, the specific addresses for storing the original null numbers, the library/machine code for invoking the microcontroller 10 to read the UID of the portable memory device 100, and the algorithm for generating the identification associated with the electronic device, so that it may access the data stored in the hidden area 22 and the shield area 23 for performing the method for managing access to DRM content. It is to be understood that, since the NEDCS is compiled, the preconfigured information should be secure.
It is to be understood that, unlike the conventional designs, the storage device used for carrying the protected content in the invention, i.e., the portable memory device 100, is a commodity memory, such as an SD card, a Micro SD card, a USB flash drive, or an SSD. Since no custom microcontroller, custom memory chip, or additional WORM memory is required, costs and engineering efforts are saved. Also, different digital content companies may easily select different algorithms for generating the original null numbers and the identifications for electronic devices to ensure the confidentiality therebetween. In addition, the designs of the invention, such as the shield area 23 not being accessible even by bit-to-bit mirror copying, and the original null numbers being written to specific addresses among all addresses in the hidden area 22, provide highly secure protection for content.
While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. Those who are skilled in this technology can still make various alterations and modifications without departing from the scope and spirit of this invention. Therefore, the scope of the invention shall be defined and protected by the following claims and their equivalents.
