XML.com: XML From the Inside Out
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The W3C, P3P and the Intermind Patent

November 03, 1999

Last week, the W3C published an analysis from Pennie & Edmonds LLP on whether implementations of their Platform for Privacy Preferences Project (P3P) would infringe a patent held by Seattle-based Intermind Corporation.

The analysis confirmed that it would be possible to implement P3P without infringing the patent—great news for implementors and users of the new standard—but the episode raises important issues about protection of the freedom to implement open standards.

A peculiar twist to this case is that Intermind themselves were involved in the W3C working groups on P3P, and had declared during that time that they had a patent pending that may impact the new standard.


Overview of P3P
Intermind Corp.
Intermind's Patent
Analysis of P3P and US Patent 5,862,325 by the W3C's legal counsel.
P3P 1.0 Working Draft
APPEL Working Draft

P3P itself is a good example of the flexibility and extensibility that is the promise of XML and RDF. Essentially, a P3P implementation informs a user of a web site's privacy practices and allows them to control what information they disclose to a site, and how the site is allowed to use it. For a summary of P3P's features, see the sidebar "Overview of P3P".

Part of P3P consists of rules enabling automatic negotiation of privacy concerns by a client-side program linked to the browser with the web site's server. This negotiation will be performed by an agent program on behalf of the user.

It is at this point where the conflict with the Intermind patent begins: agents automatically transferring data and interacting on behalf of both and information provider and consumer.

This model is not restricted to P3P: software agents performing automatic negotiations are likely to be a prominent feature in the e-commerce systems of the near future. Thus the issue of exactly what the Intermind patent does and does not claim is of prime importance for today's XML implementors.

In this article we examine the claims of the Intermind patent, the reasons P3P doesn't infringe the patent, and review the implications for the future.

What is covered by the Intermind patent?

The Intermind patent, entitled "Computer-based communication system and method using metadata defining a control structure", essentially defines an automated communication system where a provider computer transfers to a consumer computer an object (referred to as a "communications object") containing data, metadata and methods.

The transfer of "methods" means that a server computer can transfer rules to a client computer that can be executed at a later time. For example, a rule could be sent to the client which dictates schedules and conditions for retrieval of content from a publisher. These rules control "IF...THEN" aspects of the communications relationship between a consumer and provider.

So what distinguishes Intermind's technology from prior art in this area? After all, transfer of data, metadata and program code from server to client is nothing new.

"The distinctions between other metadata technologies and ours are very real," Peter Heymann, one of Intermind's founders, insists. "What makes ours unique is that the metadata is used to define the control processes."

"For example, groupware technologies rely heavily on metadata, such as the topic names in a Notes discussion database. However, the overall system uses a fixed architecture defining how information is delivered and shared. Metadata-based channel technologies will "open this up" the same way the Web has freed us from proprietary, closed document formats."

"Many people observe that metadata is involved in many other communications technologies, and that's absolutely right. In fact, metadata is the very foundation of the Web—the tags in every web page are metadata that describe the information contained between the tags. A browser is a program that knows how to process that metadata to display and link that information."

"Our patent is focused on a new way to automate communications. Our technology relies on the transfer of metadata from an author to a subscriber in order to control the subsequent delivery of information in either direction between the two.

"What makes it unique is that the metadata is used to define the control processes. Specifically this means a process to automatically detect and transfer updates from the publisher to the subscriber, or a process to automatically deliver subscriber information back to the publisher."

The applicability of such a technology is obviously broad. In fact, Intermind registered 126 claims on its patent for this technology, covering among other things its application in conjunction with existing technologies such as digital signatures, push and pull communications, and a variety of protocols.

The point of issue between the Intermind patent and the P3P work is whether the transfer of data and metadata within a P3P implementation, and negotiation between client and server, constitutes the utilization of a "communications object" mechanism as defined by the patent.

Peter Heymann commented on the scope of their patent:

"Does it cover XML and RDF, absolutely not. Our patent position doesn't cover either one per se. XML and RDF are standards defining an extensible markup language and extensible semantics, respectively. A range of communications control structures that are likely to be built with XML and RDF will infringe, however."

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