Irdeto Access, Inc. v. Echostar Satellite Corp.

• Decision Date: 14 September 2004
• Docket Number: No. 04-1154.,04-1154.
• Parties: IRDETO ACCESS, INC. (formerly known as TV/COM International, Inc.), Plaintiff-Appellant, v. ECHOSTAR SATELLITE CORPORATION (now known as EchoStar Satellite L.L.C.), Defendant-Appellee, and Kudelski, S.A. and Nagravision S.A., Defendants-Appellees.
• Court: U.S. Court of Appeals — Federal Circuit

383 F.3d 1295

IRDETO ACCESS, INC. (formerly known as TV/COM International, Inc.), Plaintiff-Appellant, v. ECHOSTAR SATELLITE CORPORATION (now known as EchoStar Satellite L.L.C.), Defendant-Appellee, and Kudelski, S.A. and Nagravision S.A., Defendants-Appellees.

No. 04-1154.

United States Court of Appeals, Federal Circuit.

DECIDED: September 14, 2004.

David A. York, Latham & Watkins LLP, of Menlo Park, California, argued for plaintiff-appellant. With him on the brief was David S. Foster, of Chicago, Illinois.

Philip L. Cohan, Piper Rudnick LLP, of Washington, DC, argued for all of the defendants-appellees. With him on the brief was James M. Heintz for Kudelski, S.A., et al. Also on the brief was Robert R. Brunelli, Sheridan Ross, P.C., of Denver, Colorado, for Echostar Satellite Corporation.

Before NEWMAN, MICHEL, and BRYSON, Circuit Judges.

MICHEL, Circuit Judge.

Irdeto Access, Inc. ("Irdeto") appeals the decision of the United States District Court for the District of Colorado granting summary judgment of noninfringement to Echostar Satellite Corporation, and Kudelski, S.A. and Nagravision, S.A. (collectively, "Echostar"). Irdeto Access, Inc. v. Echostar Satellite Corp., Civil Action No. 98-M-1291 (D.Colo. Sept. 26, 2003) ("Summary Judgment Order"). Because we find no error in the district court's claim construction, we affirm the summary judgment of noninfringement.

I. BACKGROUND

A. The '020 Patent

Irdeto owns U.S. Patent No. 4,531,020 ("the '020 patent") directed to a system for controlling the broadcast of digital information signals by using three layers or tiers of complementary encryption and decryption keys — "service keys," "group keys," and "box keys."

The '020 patent abstract describes:

A method of controlling the simultaneous broadcast of enciphered digital information signals, for example in a radio or television broadcast environment, to a plurality of subscribers provides several levels of enciphering keys. The broadcast digital information signal is in a broadcast common service enciphering key and communication between the transmitter and subscribers may take place in a box key or in a group enciphering key common to a group of subscribers having a common interest in the reception of broadcast signals of a particular type. Each receiver will decipher the broadcast digital information in a specific service key which is common to that broadcast. The service key may be changed at one or more subscribers by communicating the change in the service key to the subscribers by means of the group enciphering key. Further, the group enciphering key may be changed at one or more subscribers or new groups may be formed among subscribers by communicating to the subscribers in one or more group enciphering keys.

B. Specification

The specification describes "group keys" as "common to a group of subscribers, all of whom are to receive a specific type of broadcast." '020 patent at col. 2, ll. 23-24. "There may be a substantial number of groups associated with a specific communication system and an individual subscriber may itself belong to more than one or a plurality of groups." Id. at col. 2, ll. 24-28. The number, type, and composition of groups change according to subscriber preferences: "From time to time subscribers' tastes and desires in programming change and thus it is necessary to change groups, to reform groups and to add or delete subscribers from a particular group." Id. at col. 2, ll. 36-39. Groups may be formed by content or geography:

For example, there may be a group composed of those interested in adult movies, those interested in opera, those interested in specific types of sports programs. The group may be formed of those in a specific geographical area. The numbers and types of groups are almost infinite and normally each subscriber will be able to belong to a plurality of groups and will have a group key and group ID associated with each such group.

Id. at col. 5, ll. 28-36.

In the event that one or more group keys is compromised, a box key peculiar to each subscriber provides "a final means for insuring security and privacy."' 020 patent at col. 2, l. 60. The individual box keys allow the broadcaster to communicate in complete privacy with individual subscribers, to reform groups or change the group key. According to the specification,

there need not be a logical distinction between group keys and box keys, or group addresses and box addresses. The box address/box key pair simply constitutes another subscriber subset (group) to which there happens to be only a single member.

Id. at col. 3, ll. 7-12 (emphasis added).

C. Claims

Independent claim 1 recites a three-step method for the use and distribution of keys to subscribers:

1. A method of controlling the simultaneous broadcast of enciphered digital information signals to a plurality of subscribers in which each subscriber has a permanent box enciphering key; in which the broadcast digital information signal is in a service enciphering key; and in which communication to subscribers may take place in a group enciphering key common to a group of subscribers having a common interest in the reception of broadcast signals of a particular type, including the steps of:

(a) simultaneously broadcasting digital information signals in a specific service key, which digital information signals are deciphered by subscribers having the service key,

(b) changing the service key at subscribers by simultaneously communicating the change in service key to subscribers in at least a portion of a group, such communication being in the group enciphering key,

(c) changing the group enciphering key in at least a portion of the subscribers in a group by communicating such change in the group enciphering key to the selected subscribers in the group, with each communication to a subscriber in the group being preceded by an address to designated subscribers in the group.

'020 patent at col. 6, ll. 20-43.

The other independent claim of the '020 patent, claim 4, recites the receiver used to decipher encrypted signals:

4. A receiver for deciphering broadcast digital information signals enciphered in a broadcast common service enciphering key including:

(a) a service data decryptor using a broadcast common service deciphering key to decipher broadcast digital information signals,

(b) memory storage means for retaining an individual subscriber box deciphering key, at least one changeable group deciphering key, and one or more addresses specific to a subscriber and its specified group or groups,

(c) and a control channel decryptor having a control channel input and being connected to said memory storage and service data decryptor, comparison means for determining if a control channel message is addressed to a specific subscriber, said control channel decryptor using the box deciphering key or a group deciphering key to decipher a control message as to a change in the service deciphering key or a change in or formation of a group deciphering key.

'020 patent at col. 6, l. 56 — col. 7, l. 7.

D. Prosecution History

During prosecution, the examiner rejected all pending claims of the application that issued as the '020 patent as indefinite under 35 U.S.C. § 112, ¶ 2, explaining that,

The claims have certain "Key" modifiers, i.e. "box", "group", "service" which have no accepted meaning within the art thus [sic] are not understood. Applicant should make some attempt to differentiate the claimed keys and prevent them from being taken as the same element, i.e. the "box", "group" and "service" key are the same key.

Agreeing that the "key" modifiers have no accepted meaning in the art, applicant responded:

Referring first to the Examiner's rejection under 35 U.S.C. § 112 on the basis that the claims have certain "key" modifiers which have no accepted meaning in the art, we believe the Examiner is well aware of the substantial body of law which states that a patentee or in this case a patent applicant may be his own lexicographer. We believe that the modifiers for key — "box", "group" and "service" — are very adequately described in the specification and therefore there is a complete foundation for the use of these terms in the claims.

Applicant concluded that "[e]verything considered, we do not believe there is any accepted terminology in the art and since the applicants have described their specific keys in the specification, we believe that the claims are not indefinite."

In addressing a rejection of all claims for obviousness, applicant, inter alia, amended claim 1 to add step 1(c), and explained that "[a] group may be as small as a single individual or it may be substantially larger." Applicant then summed up the novelty of the invention as follows:

We repeat that the art does not disclose a three-tier communication system or the possibility of reforming or changing or creating new groups within a subscriber base by communicating to individual subscribers in either a box key or in a group key.

(emphasis added).

The Examiner thereafter allowed all pending claims.

E. The Accused DISH Network System

In the accused DISH Network system, digital television signals are encrypted and decrypted using a key called a "Control Word." The district court found, and the parties do not dispute, that Control Words correspond to the "service keys" in claim 1(a). The DISH Network changes Control Words very frequently. Changes in Control Words are, in turn, communicated through Entitlement Control Messages or ECMs — encrypted using the so-called "Transmission Key" — broadcast to all active receivers within the system. As the district court found, and as the parties do not dispute, the Transmission Key is shared by all subscribers within the DISH Network system. It is also undisputed that the accused system has no key associated with groups organized by viewer programming preference, geographic area, or any other subset of the total DISH Network...