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Description  |
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FIELD OF THE INVENTION
The present invention relates generally to monitoring the distribution of information that is accessible through a public network and, in particular, to a method and system for using key-based encryption to inhibit and track unauthorized
distribution by a key holder. The invention has particular application with regard to the commercial distribution of copyrighted works or other proprietary subject matter over a public network.
BACKGROUND OF THE INVENTION
The advent of widely available public computer networks, and particularly public networks capable of supporting multimedia functions such as the Internet, presents a great opportunity for consumers and content providers such as music publishers.
Such networks afford content providers increased access to an ever growing market. Consumers benefit from improved access to information and greater convenience. Moreover, in some cases, the digital nature of the information received over a network is
preferable to more conventional modes such as printed media. For example, digital sheet music can be printed to replicate its printed media counterpart. Additionally, the digital sheet music can be directly processed by audio and video playback
programs, as well as by a variety of digital musical instruments and equipment such as Musical Instrument Digital Interface (MIDI) devices.
Despite this potential, content providers have been reluctant to embrace this market in many cases. One reason for this reluctance has been a perceived threat that access to proprietary subject matter such as copyrighted music over a public
network will erode ownership interests in and revenues from such subject matter. The concern is that unscrupulous persons will wrongfully access such subject matter or that authorized users, having rightfully accessed the subject matter, will thereafter
distribute the subject matter in contravention of the content providers' rights. Although such possibilities exist in connection with other modes of distribution, public network distribution is thought by some to present peculiar dangers due to the ease
with which widespread distribution can be accomplished, e.g., via bulletin boards and the like.
Indeed, conventional computer security systems developed to control access to restricted access data are not well-suited to address these concerns of content providers. For example, access password systems are somewhat effective in limiting
access to designated information, but do not afford protection once the information is transmitted from the server system to a public network. Encryption systems have been devised to prevent use of information that is wrongfully intercepted as a result
of transmission over a network. In this regard, in key-based encryption systems, authorized clients are provided with a decryption key. The protected information is then transmitted in encrypted form to prevent use by any intercepting party. The
authorized client receives the encrypted information and uses the decryption key to decrypt the information. Unfortunately, such encryption systems generally do not provide adequate safeguards to discourage the authorized clients from subsequently
redistributing the protected information.
SUMMARY OF THE INVENTION
The present invention is directed to a method and system for controlling access to protected information from a server, as well as discouraging and tracking subsequent redistribution of such information after it has been transmitted from the
server. The invention facilitates commercial distribution of proprietary subject matter through public or open networks by providing improved protection of proprietary rights and increasing the likelihood that infringing activity will be corrected.
Moreover, the invention provides increased marketing flexibility by allowing for limited, multiple-use authorization and pre-purchase sampling of copyrighted works or other confidential subject matter. The invention also provides a novel, encryption
on-demand capability which, it is believed, has not been feasible in connection with physical storage media such as CD-ROM and magnetic storage media.
According to one aspect of the present invention, a method and corresponding system is provided for monitoring distribution of information accessible over a public network on a client-specific basis. The method includes the steps of:
establishing a database of information at a server; encrypting at least a portion of the information using a key-based encryption system; in connection with a request by a client, assigning a client-specific key to the client; and transmitting the key to
the client. The client-specific key includes some indicia that can be used to identify the client, thereby allowing for monitoring of information use on a client-specific basis.
The database can include various types of information, for example, digital sheet music, literary or artistic works, software programs, or other subject matter transmittable in digital form. Any identifying information can be coded into the key
for client identification. Examples include: personal or financial data provided by the client; address information for the clients' computer or web site; account numbers or serial numbers; other information for identifying the computer used by the
client; and abbreviated or encoded versions of any of the above. Conveniently, such information can be stored in a separate client database and indexed to the key. Preferably, the decryption system requires entry of the key each time the protected
information is used (i.e., the system does not store the information in decrypted form) and appends the client identifying information to any redistributed digital or hard copies of the information. In this manner, the client is discouraged from
redistributing the protected information because the key is required to use the information in its original digital form, and distribution of the key or an identified hard copy may involve disclosure of sensitive information or otherwise create a
traceable record of the client's infringing activity.
According to another aspect of the present invention, a method and corresponding system is provided for enabling transaction-specific access authorization with respect to protected information. The method involves the use of a key-based
encryption system, such as generally discussed above, where decryption keys are assigned on a transaction-by-transaction basis. That is, decryption keys are assigned on demand in connection with a transaction involving communication of the protected
information from the server to a client. For example, the transaction may involve the purchase of a copy of sheet music, a digital musical score or other protected information, or it may involve paying a license fee to use such information a designated
number of times, for a designated duration, or during a designated license term. The key can include information sufficient to identify the subject information and/or the client. The invention thereby allows for transaction-specific authorization and
increased marketing/distribution possibilities.
According to a further aspect of the present invention, partially encrypted information is transmitted prior to providing a decryption key so as to allow for sampling of the information before a transaction is consummated. In particular, the
associated method involves establishing a database of information at a network server, encrypting a portion of the information and receiving an access request. Upon receiving an access request, a selected portion of the information is transmitted in
partially encrypted form and, thereafter, a decryption key is transmitted to the client. By way of example, the partially encrypted information can be sheet music where only the first page of a score is unencrypted for viewing. The client can thereby
browse through a selection of scores prior to making a purchasing decision, authorizing payment and, in response, receiving a decryption key.
According to a still further aspect of the present invention, a method and corresponding system is provided for enabling post-transmission monitoring of information use by a client. The method includes the steps of: receiving encrypted
information and storing the information in memory in its encrypted form; receiving a decryption key and storing the key in memory separate from the encrypted information, for example, in a cache; identifying a request by a client to access the
information; in response to the request, retrieving the encrypted information and key from memory and, thereafter, decrypting the information; and outputting the information for use by the client. The method can be implemented, for example, by
playback/display software running on a client computer. The software can be programmed for limiting access to the protected information according to transaction parameters, e.g., limiting access to the scope of a license purchased by the client. The
access request can be an "open file," "display," or "print" message or the like.
In a preferred implementation, the protected information is never saved in its decrypted form but, rather, is only decrypted on a just-in-time basis when the corresponding file(s) is opened for use. Accordingly, redistribution of the information
in its decrypted form is discouraged or practically prevented. Moreover, in order to permit third-party use of the information, redistribution of the information in its encrypted form will also require distribution of the decryption key, which may be an
unattractive option for the client.
The present invention thus allows for monitoring access to protected information on a server and subsequent use or redistribution by a client. Additionally, the invention allows for tracking of any unauthorized redistribution and thus
facilitates enforcement of server rights. The invention also provides for increased marketing/distribution options and novel on-demand decryption key coding. By virtue of these and other advantages, the invention promotes distribution of proprietary
subject matter over public networks to the mutual benefit of consumers and content providers.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention and further advantages thereof, reference is now made to the following detailed description, taken in conjunction with the drawings, in which:
FIG. 1 is a schematic diagram of a computer system in accordance with the present invention;
FIG. 2 is a chart providing a functional overview of the distribution monitoring system of the present invention;
FIG. 3 is a diagram of the Music Viewer download function of the system of FIG. 2;
FIG. 4 is a diagram of the music download function of the system of FIG. 2;
FIG. 5 is a diagram of the on-line music purchase function of the system of FIG. 2;
FIG. 6 is a flow chart of the music printing function of the system of FIG. 2;
FIG. 7 is a flow chart of the music viewing function of the system of FIG. 2;
FIG. 8 is a schematic diagram of the encryption/decryption components of the system of FIG. 2; and
FIG. 9 is a flow chart of the encryption/decryption function of the system of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
The distribution monitoring system of the present invention is useful in a variety of applications where it is desired to monitor the distribution of proprietary subject matter over a public network. In the following description, the invention
is set forth in the context of monitoring distribution of digital musical scores over a network. It will be appreciated that this particular application is set forth for the purpose of illustrating the invention, and various aspects of the invention
have broader application as defined by the claims below.
FIG. 1 illustrates an encryption secured computer system 10 according to the present invention. The computer system 10 includes a server 12 that can communicate with clients 14-20 across a public network 21 such as the Internet. In the case of
the Internet, the server 12 can be accessed via the Netscape 2.01 or Microsoft Internet Explorer 3.0, or higher browsers. The server 12 generally includes a processor 22 and a library or database of digital musical scores stored in a memory 24 as files
26-32. As discussed in detail below, the server 12 is operative for receiving access requests from clients 14-20, assigning decryption keys or passwords and transmitting an accessing program and selected scores to the clients 14-20 over network 21. A
number of other functions relating to receiving payment, indexing and storing encoded decryption passwords and the like are also performed by server 12.
For present purposes, the clients 14-20 may be considered as being functionally equivalent. Details of only one of the clients 14 are shown in FIG. 1. Generally, the client 14 includes a central processing unit (CPU) 34, an internal cache 36
and/or external cache 38, memory 40 and input/output (I/O) hardware 42, all interconnected via data bus 44. The CPU, which may include any suitable microprocessor, is operative for downloading and running the accessing program, accessing memory 40 and
caches 36 and 38, and communicating with I/O hardware 42. In the illustrated embodiment, the CPU 34 also includes a built-in, internal cache for storing the decryption key used to decrypt downloaded musical scores. Generally, cache 36 is an area of
extremely fast Random Access Memory (RAM) for storing frequently used or time critical data so as to allow for faster operation. The cache 36 can be accessed more rapidly than memory 40. Alternatively, the decrypting key can be stored in an external
cache 38, which may comprise a RAM chip located on the computer motherboard. Memory 40, which is separate from caches 36 and 38, may include computer memory as well as the storage of floppy disks, CD-ROM drives and hard drives. The I/O hardware 42 can
include a number of types of devices including a mouse, keyboard or other user input device; a viewing monitor; a printer; or a MIDI device.
FIG. 2 provides a functional overview of a music distribution monitoring system 46 used in connection with the computer system 10 of FIG. 1. As shown in FIG. 2, the monitoring system 46 can be broken down into a number of functions that are
executed by logic on the server and/or a client. The functions of the illustrated system 46 include: downloading (48) a music accessing program, in this case designated the "Music Viewer," for use by a client in accessing music files stored on the
server; downloading (50) a selected musical score from the server; purchasing (52) music on-line (and thereby obtaining an access license and encoded decryption key); printing (54) and/or viewing (56) the music and music encryption/decryption. It will
be appreciated that the music may also be reproduced from digital information using a MIDI device or the like. Each of these functions is discussed in turn below.
FIG. 3 illustrates the Music Viewer download function of one implementation of the present invention. After communication between the server and client has been established through the network, the client initiates the download function by
requesting (58) the server to download the program. This request can be entered by following appropriate prompts from the server site. The server receives (60) the download request and sends (62) the Viewer software package to the client. Upon
receiving (64) the software package, the client runs the setup code to install the Music Viewer software. In order to access musical scores stored in the server library in the illustrated system, the client is assigned a unique Viewer identification
code. Accordingly, the client is prompted to request (66) a Viewer ID as part of the download procedure. In response to the ID request, the server generates (68) a Viewer ID and logs the ID in a Viewer database. The server then sends (70) the newly
generated Viewer ID to the client and logs the transmission time and date, the Internet Protocol (IP) address (or similar information for other networks) of the client, and the client's machine name or type (as entered by the client user or determined
from a transmission header or the like). The client then receives (72) the assigned Viewer ID and a successful installation is thus completed.
The system of the illustrated embodiment allows the client user to browse through the music library and view a selected portion, e.g., the first page, of musical scores prior to consummating a transaction by purchasing a music copy or paying a
license fee. FIG. 4 illustrates the associated pre-purchase music download function. The function is initiated when the client selects a score to sample and requests (74) the music from the server. In this regard, the score may be selected from a list
of titles by scrolling through the library and clicking on a selected title, by using a search function to call a title, or by any other appropriate means. The Viewer ID is also sent to the server at this time. Upon receiving the request, the server
finds (76) the requested musical score, compresses and encrypts (or partially encrypts) the score as will be described below, and stores the encrypted score in the download area. In addition, the server assigns and logs a decryption key that is unique
to the client and also logs an identification code for the score, the download IP, and the Viewer ID for the transmission. For example, the key can be a password composed of two 32 bit numbers where one of the numbers is an index to identify the client
in a client database and the other number is random, or encoded with additional information as desired. By indexing the key or password to the client database in this manner, the password can be used to identify the client, look up license or account
information and otherwise monitor distribution on a client-specific and transaction-specific basis.
The server then sends (78) the client the Uniform Resource Locator (URL) address of the newly encrypted music. Upon receiving (80) the URL, the client can request (82) a download of the file or files containing the encrypted music. The server
then finds (84) the encrypted music in the download area, queues up the music, and downloads (86) the music to the client. The client receives (88) the encrypted music and stores the music in memory, e.g., computer memory, hard drive storage, etc. At
this point in the illustrated implementation, i.e., prior to purchase, only the first page of the score is not encrypted. Accordingly, the client user can play and view (90) the first page of the music to verify that the downloaded score is the score
desired by the user and to otherwise e | | |
