Abstract:
A system and method using of a trusted third party to provide a description of an information product to potential buyers without disclosing the entire contents of the information products, which might compromise the interests of the seller. The buyer trusts the third party to give an accurate description of the information that is for sale, while the seller trusts the third party not to reveal an excessive amount of the information product&#39;s content. The system can include a seller of information products, a buyer of such products, and a trusted third party summarizer, each operating as a node in a communications network, such as the internet.

Description:
FIELD OF THE INVENTION 
     The invention relates to the distribution of information products in digital form. 
     BACKGROUND OF THE INVENTION 
     In an economy that supports the buying and selling of information, vendors need to be able to let their customers know what they have for sale, without giving away too much of the valuable information. Buyers need to be able to determine the characteristics of information they might want to purchase, without having to trust the claims of the sellers. For some purposes, informal or partial methods work: a magazine subscriber is willing to risk that future issues may be poorer in quality than past ones; a database provider may be willing to allow a potential customer a number of free trial searches; and so on. But for other applications, it is highly desirable for a potential buyer to be able to reliably determine various facts about a piece of information before buying it, and absolutely critical to the vendor that the buyer not be given actual read access to it. 
     SUMMARY OF THE INVENTION 
     The invention involves the use of a trusted third-party to provide a description of an information product to potential buyers without compromising the interests of the seller. The buyer trusts the third party to give an accurate description of the information that is for sale, while the seller trusts the third party not to reveal too much of the information&#39;s content. For brevity, we will refer to the third party in this system as the &#34;summarizer&#34;, although it is not a necessity of this invention that what is produced is a summary in a strict sense. 
     For each piece of information covered by the system, the summarizer computes some function of the information&#39;s content. For the purposes of computing the value of the function, the summarizer has full access to the information. In one embodiment of the invention, the function computed by the summarizer is designed to indicate to some number of potential buyers how valuable the information is to them. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram of a system in accordance with the invention. 
     FIGS. 2a-2f are examples of display screens of a system operating in accordance with the invention. 
     FIG. 3 is a flow diagram describing a method in accordance with the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention is a system and method for using a trusted third party, or &#34;summarizer&#34;, to assess the usefulness of an information product. FIG. 1 is a block diagram of a system in accordance with the invention. FIG. 3 is a flow diagram showing the steps carried out by the system of FIG. 1, and will be discussed in conjunction with FIG. 1. 
     The system includes a vendor system 100, which can take the form of, for instance, a suitably programmed general purpose computing system, having access to a storage device 102 containing one or more information products that the vendor offers for sale. The vendor system can be accessible to the public by means of an Internet web site. The information products can include various publications, such as papers, books, journals, compiled reference works, government documents, etc. The vendor system 100 is connected to a client (buyer) system 103 via a communication system, such as the Internet. The client system, like the vendor system, can be a general purpose computing system programmed to carry out the functions described herein. 
     In accordance with the invention, the client system 103 will contact the vendor system 100 via the Internet. The buyer might locate this particular vendor by performing an Internet search (using any known search service) for vendors holding information products of the kind the buyer is looking for. When prompted, the buyer can submit a request for a listing of information products offered by the vendor that concern a particular topic. Employing data-transfer protocols (such as HTTP, FTP or WAIS) and search protocols and algorithms known to the art, the vendor displays a list of information products that may be of interest, along with the price that the vendor will charge for each. The products and their prices are displayed as a menu or form in the Web browser. The extent of information displayed about the product can be the product&#39;s title, a list of key terms or subjects discussed in the product, or an abstract of the product. Thus, the following exchange of information takes place between the vendor and buyer systems, as shown by the arrows connecting blocks 100 and 103 in FIG. 1: 
     From Buyer to Vendor: desired subject matter/search criteria; 
     From Vendor to Buyer: contents of the Vendor&#39;s free Web pages, search results, including product titles and prices. 
     If the prices are acceptable to the buyer, or the information product descriptions very convincing, the buyer may choose to purchase copies of one or more information products on the spot, using an electronic-payment system 104 and protocols known to the art (see, e.g., D. Chaum, &#34;Online Cash Checks&#34;, Advances in Cryptology, EUROCRYPT &#39;89, J. J. Quisquater &amp; J. Vandewalle (Eds.), Springer-Verlag, pp. 288-93). In such case, the buyer will provide a payment authorization to the electronic payment service which will allow payment of the vendor for the information product purchased. The vendor&#39;s web site can, for instance, provide a convenient mechanism for completing the transaction, such as a link to the electronic payment service. 
     In accordance with the invention, the vendor system 100 will provide the buyer with the option to make use of a summarizer service, by means of pressing a different button on the form displayed on the Vendor&#39;s server. If the buyer elects to have the information product evaluated by the summarizer, he is presented with the names of trusted summarizer services that the vendor has previously contracted with. The buyer is presented with the option of choosing any one of the summarizers. When he chooses one, the name of the vendor and information identifying the information products to be evaluated are sent via the communications network to the summarizer service 106. The summarizer 106 can be a suitably programmed general purpose computer connected to the communications network. The buyer and the summarizer may now negotiate on price, and the buyer may provide to the summarizer a set of keywords representing the information he hopes will be found in the information products. 
     The data to be exchanged in this phase of the transaction is as follows: 
     From Buyer to Vendor: request for summarizer evaluation; 
     From Vendor to Buyer: names of contracted summarizers; 
     From Buyer to Summarizer: name of vendor, information identifying the information products to be evaluated; 
     Between Summarizer and Buyer: negotiation on price of the evaluation service; 
     From Buyer to Summarizer: Keywords. 
     The summarizer 106 then connects to the vendor system 100, and authenticates itself, to gain unrestricted access to the information products in question. Applying search and evaluation methods known to the art (for instance, a simple counting of the density of the buyer-supplied keywords and other words known to be correlated with them; or a more sophisticated system using knowledge of English grammar to analyze the semantic structure of each information product and use that knowledge in conjunction with a lexicon of related terms, and a neural network trained to recognize relevant connections to estimate the semantic distance between each information product and the buyer&#39;s keywords, etc.), and the summarizer computes a score for each information product, reflecting how likely it is to contain the information the buyer is looking for. This information is then relayed back to the buyer via the communications network, who is charged the agreed-upon price for the evaluation. 
     The data exchanged in this phase of the transaction: 
     From Summarizer to Vendor: names of information products to be evaluated, and data indicating the authenticity of the summarizer as an evaluator; 
     From Vendor to Summarizer: information product contents; 
     From Summarizer to Buyer: acknowledgement of request for services, request for payment information; 
     From Buyer to Summarizer: payment information; 
     From Summarizer to Buyer: information product scores; 
     From Summarizer to Electronic Payment System: payment information. 
     After reviewing the scores of the information products in question, the buyer then decides which ones to actually purchase from the vendor, and does so using a form designed for this purpose in the vendor&#39;s web site. 
     The data exchanged during this phase of the transaction: 
     From Buyer to Vendor: request for specific information products, payment information; 
     From Vendor to Buyer: information product contents; 
     From Vendor to Electronic Payment System: authorization for payment to vendor from the buyer&#39;s account. 
     It will be recognized by those skilled in the art that the above represents only one possible model. In other models, the evaluation service might be paid by the vendor rather than the buyer, the evaluation service might provide summaries of the information products rather than keyword-based scores, the vendor might obtain signed summaries or scores from the summarizer and provide them to the buyer along with advertising or search results, the summarizer&#39;s evaluation algorithms might be embodied in a program that both vendor and buyer can run, and so on. 
     FIGS. 2a-2f show examples of screens that might be displayed on the buyer&#39;s monitor when dealing with a vendor of information products in accordance with the invention. 
     In FIG. 2a, a welcome screen is displayed to the buyer, inviting the buyer to enter desired search terms. The buyer selects the &#34;submit&#34; key to send the search request to the vendor. The vendor can then perform a search of all information products for the search terms and return a result screen to the buyer, for example as shown in FIG. 2b. 
     As shown FIG. 2b, one of the options of the buyer is to have the information evaluated. In response to selecting the &#34;evaluate&#34; option, the buyer is presented with a list of summarizers, FIG. 2c, and is invited to select one. 
     Selection of one of the summarizers will cause a hyper-link to that summarizer, where the titles of the information products uncovered in the vendor&#39;s search will be displayed in a list, FIG. 2d, along with the price charged by the summarizer for evaluating each one. Also displayed is a field in which the buyer can enter key search terms to be used by the summarizer in conducting the evaluation. The buyer can then select individually the information products it wishes the summarizer to analyze. 
     A payment screen will then be displayed to the buyer, FIG. 2e, which will inform the user of the cost of the requested services, and request an authorization for payment. 
     After authorization of payment, the summarizer will analyze the selected information products and will return an evaluation summary screen, FIG. 2f, describing the results of the analysis. After reviewing these results, the buyer can return to the vendor&#39;s web site and order one or more of the evaluated information products, if desired. 
     Further examples: 
     It will be clear to those skilled in the art that the following examples are within the scope of the invention: 
     A service that runs a fixed function on information products being offered for sale, and makes available (and/or allows vendors to make available) the output of the function (perhaps digitally signed by the summarizer to prove authenticity); 
     A service wherein a potential buyer can submit some data to a summarizer (a personal profile, a list of key interests, and so on), and the summarizer will return a customized result based on that input, 
     A summarizer which is made available as a program, or set of programs; vendors would advertise the results of running these programs on the information products they offer for sale, and buyers would be able to verify (after purchasing the items) that the advertising was correct, by running the summarizer program themselves; 
     A system in which a prospective buyer sends a summarization program to the vendor, and the vendor runs that program in a restricted environment, allowing the program to examine the information products for sale, but not to do anything else to the vendor&#39;s system, and strictly filtering (possibly to a single buy/don&#39;t-buy bit) the communication back from the program to the buyer. 
     While the invention has been described in particular with respect to preferred embodiments thereof, it will be recognized by those skilled in the art that modifications to the disclosed embodiments can be effected without departing from the spirit and scope of the invention.