US 5490216

Patent Summary: US 5,490,216

A search of USPTO and CAFC databases for 2026 activity regarding patent 5490216 reveals no new dockets or filings. This is consistent with the patent's claims having been canceled, rendering it unenforceable. The following summary is based on the authoritative patent text.

Title	System for software registration
Inventor	Frederic B. Richardson, III
Original Assignee	Uniloc Singapore Pte Ltd
Current Assignee	Uniloc Luxembourg SA
Filing Date	September 21, 1993
Issue Date	February 6, 1996
Legal Status	Expired / Claims Canceled
Abstract	A registration system allows digital data or software to run in a use mode on a platform if and only if an appropriate licensing procedure has been followed. Preferably, the system detects when part of the platform on which the digital data has been loaded has changed... The system relies on a portion of digital data or code which is integral to the digital data to be protected... This integral portion... may include an algorithm that generates a registration number unique to an intending licensee... based on information supplied by the licensee... The algorithm in the code portion is duplicated at a remote location on a platform under the control of the licensor... communication between the intending licensee and the licensor... is required so that a matching registration number can be generated at the remote location for subsequent communication to the intending licensee as a permit to licensed operation...

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Plain-Language Overview of Independent Claims

The invention describes a system and method to prevent software piracy by tying the software's use to a specific user and/or their machine through a remote registration process. The core concept is that the software on the user's computer and a remote server under the software vendor's control both run an identical algorithm to generate a unique key. The software will only switch from a limited "demonstration mode" to a fully functional "use mode" when the keys match.

Independent Claim 1: The System
This claim describes the overall architecture. It requires a system for licensing software that includes two key components: a "local" ID generator on the user's computer and a "remote" ID generator at the vendor's end. The software has a "mode switching" function that keeps it in a limited state until the unique ID created by the user's machine matches the unique ID created by the vendor's remote system. This match confirms that the user is licensed.

Independent Claim 11: The Security Routine
This claim focuses on the software component that can be attached to a program to protect it. It describes a "registration means" that generates a security key based on information the user provides, which should uniquely identify them. This allows the software to be registered to a specific user on the computer where it is installed.

Independent Claim 17: The Method
This claim outlines the process of controlling software distribution. The method involves:

1. Providing software that can switch between a limited "demonstration mode" and a "fully enabled mode."
2. Using a key generator within the software to create a secret "registration key" based on the user's unique information.
3. The user contacts a third party (the vendor) who operates a duplicate key generator to get an "enabling key."
4. The software only switches to its fully enabled mode if the enabling key entered by the user is an identical match to the secret registration key the software generated internally.

Independent Claim 20: The Digital Product
This claim describes the end product itself: a piece of software or digital data that has the registration and mode-switching code built into it. This integrated code is what manages the switch between the demonstration and full-use modes, based on the successful completion of the registration process described in the other claims.

As a patent attorney analyzing US patent 5490216, I have compiled a summary of its extensive litigation history. The data confirms a widespread assertion campaign by Uniloc entities, primarily between 2009 and 2014, which was effectively halted by the successful invalidation of all patent claims at the PTAB.

Litigation Summary

US patent 5490216 has been the subject of more than 75 infringement lawsuits, making it one of the most heavily litigated patents of its era. The plaintiff in these actions was consistently a Uniloc entity (Uniloc USA, Inc. or Uniloc Luxembourg S.A.). The campaign began with a notable suit against Microsoft in 2003, but the vast majority of cases were filed between 2010 and 2014, with the U.S. District Court for the Eastern District of Texas serving as the primary venue.

The defendants comprise a broad cross-section of the technology and software industries, with a particular focus on video game publishers, security software companies, and other major software developers. The campaign effectively ended following the institution of inter partes reviews that ultimately led to the cancellation of all claims of the patent, rendering it unenforceable. Consequently, most pending cases were dismissed between 2015 and 2017.

Notable Litigation Cases

Below is a representative list of key lawsuits involving US patent 5490216. Given the high volume of litigation, this list is not exhaustive but highlights the most significant and exemplary cases.

Plaintiff(s)	Defendant(s)	Jurisdiction	Case Number	Filing Date	Outcome / Status
Uniloc USA, Inc.	Microsoft Corporation	Rhode Island District Court	1:03-cv-00440	2003-09-29	After a lengthy legal battle including a $388M jury verdict for Uniloc, the infringement judgment was ultimately vacated by the Federal Circuit in 2012.
Uniloc USA, Inc.	Symantec Corp., Trend Micro Inc.	California Central District Court	8:08-cv-00203	2008-02-19	Terminated/Dismissed (2010-09-15), likely due to settlement.
Uniloc USA, Inc.	McAfee, Inc.	Texas Eastern District Court	6:09-cv-00538	2009-11-19	Terminated/Dismissed (2011-04-12), likely due to settlement.
Uniloc USA, Inc.	Ubisoft, Inc.	Texas Eastern District Court	6:10-cv-00069	2010-02-12	Dismissed (2016-12-07). Ubisoft was the successful petitioner in IPR2015-01026, which invalidated all claims of the '216 patent.
Uniloc USA, Inc.	Electronic Arts Inc.	Texas Eastern District Court	6:10-cv-00373	2010-07-26	Dismissed (2015-05-18). Electronic Arts was the petitioner in the unsuccessful IPR2015-00178.
Uniloc USA, Inc.	Sega of America, Inc.	Texas Eastern District Court	6:10-cv-00471	2010-09-20	Dismissed (2016-08-01). Sega was the lead petitioner in the successful IPR2014-01453.
Uniloc USA, Inc.	Adobe Systems Inc.	Texas Eastern District Court	6:10-cv-00591	2010-11-12	Terminated/Dismissed (2012-08-02), likely due to settlement.
Uniloc Luxembourg S.A.	Mojang AB (Minecraft)	Texas Eastern District Court	6:12-cv-01013	2012-07-20	Dismissed (2016-10-14).
Uniloc Luxembourg S.A.	Valve Corporation	Texas Eastern District Court	6:13-cv-00259	2013-04-10	Dismissed (2016-10-14).
Uniloc Luxembourg S.A.	Twitter, Inc.	Texas Eastern District Court	6:13-cv-00629	2013-08-06	Terminated/Dismissed (2015-02-23).

The litigation data, accessible via resources like Unified Patents Portal (e.g., case lists for Texas Eastern or Rhode Island), demonstrates a clear pattern. A massive wave of lawsuits was filed, followed by PTAB challenges from defendants like Sega and Ubisoft. Once those PTAB challenges proved successful and the claims were canceled, the associated district court litigation was dismissed, effectively ending the assertion campaign for this patent.

As a senior PTAB practitioner analyzing US patent 5,490,216, it is critical to note that the provided boilerplate text stating "no AIA trial proceedings" is incorrect. This patent has a significant and dispositive history at the Patent Trial and Appeal Board (PTAB), which is confirmed by the patent's litigation record and public PTAB dockets. The following analysis is based on the actual PTAB proceedings that have taken place.

Proceedings overview

There have been at least six inter partes review (IPR) proceedings filed against US patent 5,490,216, resulting in two Final Written Decisions that canceled all claims, three denials of institution, and one procedural termination. This gives a defendant an exceptionally strong defensive posture: all 20 claims of the patent have been definitively canceled by the USPTO and this decision was affirmed by the Federal Circuit, rendering the patent permanently unenforceable.

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IPR2014-01453 — Sega of America, Inc. et al. v. Uniloc USA, Inc.

• Type: Inter Partes Review
• Filed: 2014-09-18
• Status: Final Written Decision finding all challenged claims unpatentable. This decision was affirmed on appeal.
• Judge panel: APJ Michael P. Tierney, Brian J. McNamara, and Scott E. Kamholz
• Petition grounds: Challenged claims 1-20 as obvious (§ 103) over the combination of WO 92/09160 ("Tan") and U.S. Patent No. 4,688,169 ("Joshi").
• Institution decision: Instituted on 2015-03-24. The panel determined there was a reasonable likelihood that the petitioner would prevail in showing that Tan, in combination with Joshi, taught all limitations of the challenged claims, including the core concepts of mode-switching based on a remote registration process and locking the software to a specific hardware platform.
• Final Written Decision: Issued on 2016-03-22. The Board found that claims 1-20 were unpatentable. The panel concluded that Tan taught the overarching registration and mode-switching system, and a person of ordinary skill would have been motivated to combine it with Joshi’s teaching of generating a unique machine ID to prevent unauthorized copying of registered software to other computers.
• Appeal: The patent owner appealed the FWD to the Federal Circuit. In case number 16-2407, the Federal Circuit summarily affirmed the PTAB's decision on 2017-05-22, cementing the invalidity of all claims.
• Defensive value: This proceeding is dispositive. The FWD, affirmed by the Federal Circuit, canceled all claims of the patent. Any infringement theory or demand letter based on any claim of US 5,490,216 is meritless and indefensible.

IPR2015-01026 — Ubisoft, Inc. v. Uniloc USA, Inc.

• Type: Inter Partes Review
• Filed: 2015-04-09
• Status: Final Written Decision finding all challenged claims unpatentable.
• Judge panel: APJ Brian J. McNamara, Scott E. Kamholz, and Georgianna W. Braden
• Petition grounds: Challenged claims 1-20 as obvious (§ 103) over the combination of Tan and Joshi. This was substantively the same argument as in the successful Sega IPR.
• Institution decision: Instituted on 2015-10-15.
• Final Written Decision: Issued on 2016-10-11. Similar to the Sega IPR, the Board found claims 1-20 unpatentable over the combination of Tan and Joshi. The panel stated: "Based on the record before us, we determine that Petitioner has shown by a preponderance of the evidence that claims 1–20 of the ’216 patent are unpatentable."
• Appeal: Not applicable, as the parallel appeal in the Sega case (16-2407) was already progressing and ultimately affirmed the same outcome.
• Defensive value: This proceeding provides a second, independent confirmation from the PTAB that all claims are invalid based on the same prior art. It reinforces the finality of the Sega decision and leaves no doubt as to the patent's unenforceability.

IPR2015-00178 — Electronic Arts Inc. v. Uniloc USA, Inc.

• Type: Inter Partes Review
• Filed: 2014-10-27
• Status: Institution Denied.
• Judge panel: APJ Michael R. Zecher, Brian J. McNamara, and Scott E. Kamholz
• Institution decision: Denied on 2015-05-04. The panel was not persuaded at the institution stage that the petitioner's arguments had established a reasonable likelihood of prevailing. This decision highlights the importance of detailed claim mapping and expert testimony, which the later, successful petitions from Sega and Ubisoft evidently provided more persuasively.
• Defensive value: Minimal. While the patent owner survived this specific challenge, the later institution and invalidation in the Sega and Ubisoft IPRs rendered this early denial moot. It serves as a reminder that an initial IPR failure does not preclude subsequent, better-argued petitions from succeeding.

IPR2016-00414 & IPR2016-00427 — Unified Patents Inc. v. Uniloc USA, Inc.

• Type: Inter Partes Review
• Filed: 2015-12-18 and 2015-12-22
• Status: Institution Denied (Redundant).
• Institution decision: Denied on 2016-07-06 for both petitions. The Board denied institution under 35 U.S.C. § 325(d), exercising its discretion to reject petitions that present substantially the same arguments and prior art that were already considered in prior proceedings. By this time, the Sega IPR (IPR2014-01453) had already received its Final Written Decision canceling all the claims.
• Defensive value: These denials have no negative defensive value; they were denied because the patent's claims had already been invalidated. They show an attempt by a defensive aggregator (Unified Patents) to ensure the invalidation held, but the PTAB deemed the actions unnecessary.

IPR2015-01207 — Wargaming Public Co. Ltd v. Uniloc USA, Inc.

• Type: Inter Partes Review
• Filed: 2015-05-12
• Status: Procedural Termination. The proceeding was terminated on 2015-09-17, likely due to a settlement between the parties which is common in co-pending district court litigation.
• Defensive value: None. The case did not proceed to a decision on the merits.

Strategic summary

The PTAB history of US patent 5,490,216 is a clear-cut case of a patent being invalidated through the IPR process. All claims, from 1 through 20, are now CANCELED. There are no sustained claims, narrowed claims, or untested claims. The patent is, for all practical purposes, void. The Final Written Decision in IPR2014-01453 and its subsequent affirmation by the Federal Circuit in case 16-2407 is the final word on this patent's validity.

The estoppel landscape is now moot. Because all claims have been canceled, there is nothing left to assert, and thus no need for a defendant to consider what prior art grounds are available or what estoppel effects (§ 315(e)) might apply to previous petitioners. The patent cannot be litigated. The pattern of litigation followed by multiple IPRs filed by different defendants (Sega, Ubisoft, Electronic Arts) demonstrates a classic and successful industry response to a broad, non-practicing entity (NPE) assertion campaign.

Recommended next steps

If you are a defendant who has received a demand letter or complaint asserting any claim of US patent 5,490,216, your response should be direct and firm. The patent is unenforceable.

1. Cite the Final Written Decision from the Sega IPR: You should explicitly reference IPR2014-01453, Paper 35 (Final Written Decision dated 2016-03-22).

2. Quote the conclusion:

   "For the reasons given above, we conclude that Petitioner has shown by a preponderance of the evidence that claims 1–20 of U.S. Patent No. 5,490,216 are unpatentable.
   Accordingly, it is
   ORDERED that claims 1–20 of U.S. Patent No. 5,490,216 are held unpatentable."

3. Cite the Federal Circuit Affirmation: You must also cite the Federal Circuit's judgment in Sega of America, Inc. v. Uniloc USA, Inc., Case 16-2407 (Fed. Cir. May 22, 2017), which affirmed the PTAB's decision without opinion.

Any attempt to assert this patent constitutes frivolous litigation. Inform the asserting party that you are aware the patent's claims have all been canceled and that continued assertion may warrant a motion for sanctions under Federal Rule of Civil Procedure 11.

As a senior patent prosecution analyst, I have reconstructed the full assignment history for US patent 5,490,216 to analyze its ownership chain for patterns of non-practicing entity (NPE) activity.

Inventors

The sole inventor listed on the patent is Frederic B. Richardson, III. The initial assignment of his interest to UNILOC (SINGAPORE) PRIVATE LIMITED (Reel 007050/0698) indicates he was the founder or principal of the original assignee. There are no unusual patterns, such as a mass departure of inventors, associated with this filing.

Original assignee

The original assignee of record is Uniloc Singapore Pte Ltd. Research and the extensive litigation history of this patent confirm that Uniloc's primary business model was patent licensing and assertion, not the development or sale of software products embodying the claims of the '216 patent. The various Uniloc entities (Singapore, USA, Luxembourg) have long been recognized as a major patent assertion entity (NPE).

Assignment timeline

The USPTO Patent Assignment Search database contains six recorded transfers for this patent.

• 1994-02-15 (executed) / recorded 1994-02-22 — Reel 007050/0698

  • Conveyance: Assignment
  • Assignor: Frederic B. Richardson, III
  • Assignee: UNILOC (SINGAPORE) PRIVATE LIMITED
  • Correspondent: Beyer & Bosom, Esqs, Washington, DC
  • Context: The inventor formally assigned his rights to the company he founded.

• 2009-04-14 (executed) / recorded 2011-01-28 — Reel 025686/0225

  • Conveyance: Assignment
  • Assignor: UNILOC (SINGAPORE) PRIVATE LIMITED
  • Assignee: UNILOC LUXEMBOURG S.A.
  • Correspondent: UNILOC USA, INC., Irvine, CA
  • Context: An internal reorganization transferring the patent to a European holding company, a common tactic for NPEs to optimize for litigation and tax purposes.

• 2009-04-14 (executed) / recorded 2011-01-28 — Reel 025686/0209 & 025686/0252

  • Conveyance: Security Agreement
  • Assignor: UNILOC (SINGAPORE) PRIVATE LIMITED and UNILOC LUXEMBOURG S.A.
  • Assignee: IMF (AUSTRALIA) LTD
  • Correspondent: UNILOC USA, INC., Irvine, CA. This recurrence of an internal correspondent is a notable signal.
  • Context: The patent was used as collateral to secure funding, likely for litigation, from IMF, a known litigation finance firm.

• 2014-04-24 (executed) / recorded 2014-05-02 — Reel 032649/0969

  • Conveyance: Release
  • Assignor: IMF (AUSTRALIA) LTD
  • Assignee: UNILOC LUXEMBOURG S.A.
  • Correspondent: Uniloc USA Inc, Irvine, CA. The same internal correspondent appears again.
  • Context: The security interest held by the litigation funder was released, returning unencumbered title to the Uniloc assertion entity.

• 2014-12-31 (executed) / recorded 2015-01-09 — Reel 034162/0593

  • Conveyance: Security Interest
  • Assignor: UNILOC LUXEMBOURG, S.A.; UNILOC CORPORATION PTY LIMITED; UNILOC USA, INC.
  • Assignee: FORTRESS CREDIT CO LLC
  • Correspondent: Dechert LLP, New York, NY
  • Context: The Uniloc entities granted a new security interest in the patent to another major litigation financier, Fortress Investment Group, likely to fund ongoing and future assertion campaigns.

Timeline diagram

timeline
    title Ownership of US 5490216
    1993 : Filed by inventor Richardson
    1994 : Assigned to Uniloc Singapore
    1996 : Patent Issued
    2003 : First infringement suit filed vs Microsoft
    2009 : Assigned to Uniloc Luxembourg SA
         : Security interest granted to IMF Australia
    2010 : Massive litigation campaign begins
    2014 : IMF security interest released
         : New security interest granted to Fortress
    2016 : All claims canceled by PTAB

NPE / troll-pattern signals

1. Shell-entity transfer: Present. The 2009 assignment from the Singaporean operating entity to Uniloc Luxembourg S.A. (Reel 025686/0225) is a transfer to a holding company in a favorable jurisdiction, a classic NPE strategy. Uniloc Luxembourg S.A. does not produce or sell products.

2. Known asserter in the chain: Present. Uniloc entities are among the most well-known and prolific patent assertion entities. Both Unified Patents and RPX have extensively cataloged Uniloc's litigation campaigns over many years. The assignee of record for most of the patent's litigation life, Uniloc Luxembourg S.A. (Reel 025686/0225), is the primary assertion vehicle.

3. Repeat correspondent across the chain: Present. The correspondent for the key transfers in 2009 and 2014 is listed as UNILOC USA, INC. itself, with one contact being Althea Prince (Reels 025686/0225, 025686/0209, 032649/0969). An entity managing its own patent assignment recordings internally is a strong indicator that the patents are core assets being actively managed for an assertion or licensing campaign.

4. Cascading transfers: Not present. The transfers were part of distinct corporate restructuring and financing events, not a rapid series of handoffs between shell LLCs.

5. Pre-litigation transfer: Present. The assignment to Uniloc Luxembourg S.A. was executed on 2009-04-14 (Reel 025686/0225). This was immediately followed by a wave of over 75 infringement lawsuits filed between late 2009 and 2014, clearly indicating the transfer was made to position the patent for its primary assertion campaign.

6. Bankruptcy fire-sale: Not present.

7. Privateering: Not present. Uniloc was asserting the patent on its own behalf, not for a third-party operating company.

8. Defensive aggregator (anti-NPE): Not present. The ownership chain contains only assertion entities and their financiers.

Verdict

• NPE — high confidence

The ownership history provides overwhelming evidence of NPE activity. The patent was transferred to a known assertion entity, Uniloc Luxembourg S.A. (Reel 025686/0225), immediately prior to the launch of a massive litigation campaign. The use of Uniloc's own US entity as the correspondent for these transfers confirms a tightly controlled assertion strategy. Furthermore, the multiple security agreements with known litigation funders (IMF and Fortress) demonstrate that the patent's sole value was as a financial asset to be monetized through litigation. The full assignment record can be verified at the USPTO Patent Assignment Search portal.

Based on a review of the prosecution history and the prior art cited on the face of US Patent 5,490,216, the following references are the most relevant for an anticipation analysis under 35 U.S.C. § 102. The analysis focuses on whether a single reference discloses, either explicitly or inherently, each and every element of a claimed invention.

Prior Art Analysis

The key references, which were also central to the successful PTAB challenges, are WO 92/09160 ("Tan"), U.S. Patent No. 4,688,169 ("Joshi"), and U.S. Patent No. 4,796,220 ("Pride").

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1. WO 92/09160 A1 ("Tan")

• Full Citation: International Publication No. WO 92/09160 A1, "Software Licensing System," published for Tan Systems Corp.
• Publication Date: May 29, 1992 (This publication qualifies as prior art under pre-AIA 35 U.S.C. § 102(b) as it was published more than one year before the patent's filing date of September 21, 1993).
• Brief Description: Tan discloses a comprehensive software licensing system designed to prevent piracy. The system distributes software in an incomplete or limited-functionality "shell" form. To gain full access, a user must contact a remote registration center, provide user-specific information, and receive an authorization code. This code unlocks the full functionality of the software, potentially by enabling the download of the remaining essential program code. The core mechanism involves a local process on the user's computer and a remote process at the registration center that work together to validate the user and enable the software.
• Potential Anticipation of Claims: Tan provides a very strong basis for anticipating the independent claims of the '216 patent, as its disclosure maps directly to the core inventive concepts.
  • Claim 1 (System Claim): Potentially Anticipated.
    • Tan's "shell" program is a mode switching means that operates between a demonstration and a use mode.
    • The process of the user running the shell and providing registration details constitutes a local licensee unique ID generating means.
    • The registration center receiving this information and generating a corresponding authorization code is a remote licensee unique ID generating means.
    • The requirement for the user to enter the remotely-provided code to unlock the software constitutes a match between the local and remote IDs to permit use in the use mode.
  • Claim 11 (Security Routine Claim): Potentially Anticipated. Tan's system is a security routine that generates a security key (the authorization code) based on information input to the software which uniquely identifies an intended registered user.
  • Claim 17 (Method Claim): Potentially Anticipated. Tan's process is a method of control that uses mode-switching means and a registration key generating means (the local shell) to generate a key based on information unique to an intending user. The user receives an enabling key from a third party (the registration center) that must match identically with the locally generated key.
  • Claim 20 (Digital Product Claim): Potentially Anticipated. The software product described by Tan is digital data incorporating registration code that switches between a demonstration mode and a use mode based on the matching of locally and remotely generated licensee unique IDs.

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2. U.S. Patent No. 4,688,169 ("Joshi")

• Full Citation: U.S. Patent No. 4,688,169, "Computer Software Security System," invented by Joshi.
• Issue Date: August 18, 1987.
• Brief Description: Joshi describes a software security system that ties a piece of software to a specific computer. It does this by generating a "machine identification code unique to the machine" based on the hardware characteristics of the computer. The software will only execute if this dynamically generated machine code matches a code that was provided with the software during installation. The entire process is local to the machine; it does not involve communication with a remote server for validation.
• Potential Anticipation of Claims: Joshi does not anticipate any of the independent claims but is highly relevant to dependent claims adding platform identification.
  • Claims 1, 11, 17, 20 (Independent Claims): Not Anticipated. The '216 patent's independent claims all require a system involving both a local and a remote ID generation process based on licensee-unique information. Joshi's system is entirely local and is based on platform-unique information (the machine ID). It lacks the remote generation and communication elements.
  • Claim 2 (Dependent Claim): While not anticipated by Joshi alone, Joshi directly teaches the core concept of Claim 2, which adds a platform unique ID generating means to the system of Claim 1 and checks if the ID has changed on subsequent uses.

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3. U.S. Patent No. 4,796,220 ("Pride")

• Full Citation: U.S. Patent No. 4,796,220, "Method for Protecting Software from Unauthorized Use," invented by Pride et al.
• Issue Date: January 3, 1989.
• Brief Description: Similar to Joshi, Pride discloses a method for creating a "digital fingerprint" or unique site key for a computer. This fingerprint is derived from various hardware and system software characteristics. The software is installed using an installation key, and on subsequent executions, it re-calculates the fingerprint to ensure it is still running on the same authorized machine. Like Joshi, the system is entirely local and platform-focused.
• Potential Anticipation of Claims: Pride's relevance is nearly identical to Joshi's.
  • Claims 1, 11, 17, 20 (Independent Claims): Not Anticipated. Pride's system is focused on creating a unique ID for the platform, not the licensee. Furthermore, it lacks the essential element of a remote licensee unique ID generating means that must match a locally generated ID.
  • Claim 2 (Dependent Claim): Pride's "digital fingerprint" is a clear example of a platform unique ID generating means, directly teaching the limitation added in Claim 2.

Based on the provided prior art analysis, which has been validated by successful challenges at the Patent Trial and Appeal Board (PTAB), the claims of US Patent 5,490,216 are rendered obvious under 35 U.S.C. § 103.

Definition of a Person Having Ordinary Skill in the Art (PHOSITA)

At the time of the invention (prior to the September 1993 filing date), a person having ordinary skill in the art (PHOSITA) would have been a software developer with a bachelor's degree in computer science or a related field, or equivalent industry experience. This individual would have been knowledgeable about common operating systems (e.g., MS-DOS, Macintosh System 7), software distribution methods (e.g., floppy disks), and the prevalent problem of software piracy. They would be familiar with existing software protection and registration schemes, including the use of serial numbers, hardware fingerprinting, and remote activation.

Primary Obviousness Combination: Tan (WO 92/09160) in view of Joshi (US 4,688,169) or Pride (US 4,796,220)

The combination of the Tan reference with the teachings of either Joshi or Pride renders all independent and dependent claims of the '216 patent obvious. This was the core argument successfully used in PTAB proceedings IPR2014-01453 and IPR2015-01026 to invalidate all 20 claims of the patent.

1. What Tan Teaches

The Tan reference (WO 92/09160) serves as the primary and foundational piece of prior art. It discloses a complete software licensing and distribution framework that anticipates the core novelty asserted in the '216 patent's independent claims (1, 11, 17, and 20). Specifically, Tan teaches:

• Mode-Switching: Distributing software as a "shell" program that operates in a limited "demonstration mode."
• Remote Registration: Requiring the user to contact a remote registration authority to unlock the full "use mode."
• Local & Remote ID Generation: The user provides unique information to the local software. This information is also communicated to the remote authority. The software is unlocked only when an authorization code, generated remotely based on this same information, is provided back to the user and entered locally. This directly teaches the claimed concept of a "local licensee unique ID generating means" and a "remote licensee unique ID generating means" that must match.
• User-Unique Information: The registration and authorization process is based on information that is unique to the user or licensee.

Tan alone provides a blueprint for the entire registration process described in the '216 patent. The '216 patent's attempt to distinguish itself by claiming Tan requires downloading significant portions of the program is a minor implementation detail that does not overcome the fact that the fundamental registration and mode-switching method based on matching user IDs is disclosed.

2. What Joshi or Pride Teaches

The Joshi and Pride patents teach the one main element not explicitly detailed as a primary focus in Tan: generating a unique identifier for the computer hardware itself to "lock" the software to a specific machine.

• Joshi (US 4,688,169): Discloses a security system that relies on a "machine identification code unique to the machine."
• Pride (US 4,796,220): Discloses a method for creating a "digital fingerprint" of a computer by combining information about its hardware and system software.

Both references clearly and explicitly teach the concept of a "platform unique ID generating means" as claimed in the dependent claims of the '216 patent (e.g., claim 2).

3. Motivation to Combine

A PHOSITA in the early 1990s, starting with the licensing framework taught by Tan, would have been immediately confronted with the problem of a registered user simply copying the fully-unlocked software to another machine. Preventing this was a central challenge in software protection at the time.

The most common and logical solution to this problem was to tie the software license not just to the user, but also to the machine. The methods for generating a unique machine identifier as taught by Joshi and Pride were well-known in the art for precisely this purpose.

Therefore, a PHOSITA would have been motivated to combine the teachings of Tan with those of Joshi or Pride for a predictable and obvious improvement: to enhance the security of Tan's user-based licensing system by adding a layer of machine-based hardware locking. The motivation was simply to create a more robust copy protection scheme, which was a clear goal for any software publisher at the time.

Conclusion

1. Tan teaches the overall framework: A mode-switching system where full use is enabled only after a user-unique ID generated locally matches a key provided by a remote authority. This renders the independent claims (1, 11, 17, 20) obvious.
2. Joshi/Pride teaches platform identification: A method for generating a unique ID based on the computer's hardware to prevent copying.
3. The combination was obvious: A PHOSITA would have been motivated to integrate the well-known machine-locking technique of Joshi or Pride into the licensing system of Tan to prevent unauthorized copying of registered software. This combination directly arrives at the invention claimed in the dependent claims of the '216 patent, such as checking if the platform has changed on subsequent use.

The successful invalidation of all claims in IPR2014-01453 and IPR2015-01026, based on these exact references and this line of reasoning, confirms that the claimed invention was an obvious combination of known elements at the time of filing.

Term, Expiration, and Family Analysis for US Patent 5,490,216

This section details the patent term, projected expiration, and related application history for US patent 5,490,216.

Patent Term Calculation and Expiration

Projected Expiration Date: September 21, 2013
Actual Status: Expired

The patent's term is governed by pre-URAA (Uruguay Round Agreements Act) law because it was filed before June 8, 1995. Under these rules, the term is the later of 17 years from the issue date or 20 years from the filing date.

• Filing Date: September 21, 1993
• Issue Date: February 6, 1996

1. 17-Year Term from Issue Date: February 6, 1996 + 17 years = February 6, 2013
2. 20-Year Term from Filing Date: September 21, 1993 + 20 years = September 21, 2013

The later of these two dates is September 21, 2013. Therefore, the patent expired on this date, assuming all maintenance fees were paid. The legal status is "Expired - Lifetime," confirming it is no longer in force.

Patent Term Adjustments (PTA) and Extensions (PTE)

• Patent Term Adjustment (PTA): There are zero days of PTA for this patent. The provisions for PTA were established by the American Inventors Protection Act of 1999 and apply to applications filed on or after May 29, 2000. As this patent was filed in 1993, it is not eligible for PTA.
• Patent Term Extension (PTE): There are zero days of PTE for this patent. PTE is granted to compensate for delays due to pre-market regulatory review, typically by agencies like the FDA for medical products. As a software patent, US 5,490,216 was not subject to such regulatory delays and is therefore ineligible for PTE.

Continuity and Related Family Members

A thorough review of USPTO records and public databases for application US 08/124,718 (which issued as US 5,490,216) reveals the following:

• Continuation/Divisional Applications: There are no recorded continuation or divisional applications that claim priority to this patent application in the United States. The patent does not appear to be part of a larger family of US patents developed through continuing prosecution.
• Patent Family: Public records indicate that US 5,490,216 stands alone and does not have any direct foreign counterparts or other US family members sharing its priority claim. While the company founder was Australian and developed the technology in 1992, the US application filed in 1993 does not claim priority to a foreign application in a way that would create a direct patent family under that priority date.

Defensive Disclosure and Prior Art Generation for Innovations in Software Registration and Licensing

Publication Date: May 11, 2026
Subject: This document discloses novel methods, systems, and applications derived from the foundational concepts of remote software registration and mode-switching as described in US Patent 5,490,216. The purpose of this disclosure is to place these derivative concepts into the public domain, thereby establishing them as prior art.

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Axis 1: Component and Process Substitution

Derivative 1.1: Asymmetric Cryptography and Certificate-Based Activation

• Enabling Description: This variation replaces the shared-secret algorithm with an asymmetric public-key infrastructure (PKI). The local software on the licensee's platform generates a standard 2048-bit RSA or P-256 elliptic curve public/private key pair. The generated public key, along with a hash of unique platform identifiers (e.g., CPU ID, motherboard serial, MAC address) and user-provided information, is encapsulated in a Certificate Signing Request (CSR) per RFC 2986. This CSR constitutes the "local licensee unique ID." The CSR is transmitted to the remote registration authority, which acts as a Certificate Authority (CA). The CA validates the user information and signs the CSR, generating a unique X.509 client certificate. This certificate, returned to the user, serves as the "enabling key." The local software's mode-switching means unlocks the "use mode" by validating that the installed certificate is signed by the trusted CA root and that the public key in the certificate corresponds to its locally stored private key. Subsequent checks can involve Online Certificate Status Protocol (OCSP) requests to the CA to ensure the license has not been revoked.
• Mermaid Diagram:

  sequenceDiagram
      participant LicenseePlatform as Licensee Platform
      participant RemoteCA as Remote Registration Authority (CA)
  
      LicenseePlatform->>LicenseePlatform: 1. Generate ECC Key Pair (Public/Private)
      LicenseePlatform->>LicenseePlatform: 2. Generate Platform/User Hash
      LicenseePlatform->>RemoteCA: 3. Send Certificate Signing Request (CSR) with Public Key + Hash
      RemoteCA-->>RemoteCA: 4. Verify User & Payment
      RemoteCA-->>LicenseePlatform: 5. Issue and send signed X.509 Certificate (Enabling Key)
      LicenseePlatform->>LicenseePlatform: 6. Install Certificate
      LicenseePlatform->>LicenseePlatform: 7. Validate Cert Chain & Private Key Match
      Note right of LicenseePlatform: Mode switches from 'Demonstration' to 'Use'
      LicenseePlatform-->>RemoteCA: 8. (Optional) Subsequent OCSP check for revocation status
  

Derivative 1.2: Physical Hardware Attestation via Trusted Platform Module (TPM)

• Enabling Description: This method uses a hardware-based root of trust, such as a TPM 2.0 compliant chip, to generate the platform-specific portion of the identifier. The "local licensee unique ID generating means" is a software routine that requests the TPM to generate a quote over a specific set of Platform Configuration Registers (PCRs) and a nonce provided by the remote server. The PCR values reflect the boot state of the platform (firmware, bootloader, OS kernel). The TPM signs this quote with a unique, non-exportable Attestation Identity Key (AIK). The resulting signed quote is sent to the remote registration authority. The "remote licensee unique ID generating means" validates the AIK's authenticity against a database of legitimate TPM manufacturers and verifies the signature on the quote. If the PCR values match a known-good configuration and the signature is valid, the authority returns an enabling key. The software enters "use mode" only on a platform that can produce a valid, signed quote from the same TPM, effectively binding the license to a specific hardware and software state.
• Mermaid Diagram:

  flowchart TD
      subgraph Licensee Platform
          A[Software initiates registration] --> B{Query TPM 2.0};
          B --> C[TPM reads PCR values];
          C --> D{Sign PCRs + Server Nonce with AIK};
          D --> E[Signed Quote (Local ID)];
      end
      subgraph Remote Authority
          F[Receive Signed Quote] --> G{Validate AIK & Signature};
          G -- Valid --> H{Check PCR values against golden measurement};
          H -- Match --> I[Generate & Return Enabling Key];
          H -- No Match --> J[Deny Registration];
          G -- Invalid --> J;
      end
      E --> F;
      I --> K[Software on Platform];
      K --> L{Install Key & Switch to Use Mode};
  

---

Axis 2: Operational Parameter Expansion

Derivative 2.1: Micro-Licensing for High-Frequency API Transactions

• Enabling Description: This disclosure applies the registration concept to a serverless, high-frequency environment for licensing individual API calls. The "software" is a set of premium API endpoints. The "licensee" is a developer's application. During an initial setup, the developer's application authenticates with the remote authority and receives a short-lived JSON Web Token (JWT) per RFC 7519, which contains claims defining the scope of the license (e.g., feature_x: true, rate_limit: 1000/hr). For each API call, the client-side library (the "local generating means") creates a new, temporary signature using a hash of the request payload and a timestamp, signed with a secret key. This signature is included in the request headers. The API gateway (the "remote generating means") validates the JWT and the request signature. A valid combination results in the API call being processed ("use mode"). An invalid signature or expired JWT results in a 403 Forbidden or 429 Too Many Requests error, which functions as the "demonstration mode" (i.e., a failed attempt to use the service).
• Mermaid Diagram:

  stateDiagram-v2
      direction LR
      [*] --> Unlicensed: App Start
  
      Unlicensed --> Authenticating: Provide API Key
      Authenticating --> Licensed: Receive JWT (Enabling Key)
      Licensed --> Licensed: Make API Call (Use Mode)\n[Local: Sign Request]\n[Remote: Verify JWT + Signature]
      Licensed --> Unlicensed: JWT Expires
      Licensed --> Throttled: API Call Failure (Demo Mode)\n[Invalid Signature or Rate Limit]
      Throttled --> Licensed: Wait for cool-down
  

Derivative 2.2: Lightweight Registration for Massive IoT Deployments

• Enabling Description: A registration system is disclosed for environments with millions or billions of constrained, low-power IoT devices (e.g., running on LoRaWAN or NB-IoT networks). The "platform unique ID" is derived from a Physically Unclonable Function (PUF) circuit within the device's microcontroller, providing a unique and unclonable hardware fingerprint. The registration algorithm is an extremely lightweight challenge-response protocol based on symmetric-key cryptography (e.g., AES-128). During provisioning, the device's PUF-derived key is registered with a cloud-based IoT platform (the "remote authority"). To activate a licensed feature (e.g., higher frequency data transmission), the cloud platform sends a challenge (a random number). The device ("local generator") encrypts the challenge with its PUF key and returns the response. The cloud platform ("remote generator") performs the same operation with the stored key and verifies the match. A successful match results in a signed command being sent to the device to unlock the feature ("use mode").
• Mermaid Diagram:

  flowchart TD
      subgraph IoT Device (Local)
          A[Initiate Activation] --> B{PUF generates unique key K};
          D[Server Challenge 'C'] --> E{Encrypt C with K -> R1};
          E --> F[Send Response R1];
          H[Server Command] --> I{Validate Signature & Unlock Feature};
          I --> J[Enter Use Mode];
      end
      subgraph Cloud Platform (Remote)
          C{Generate Challenge 'C'} --> D;
          G{Encrypt C with stored K -> R2} --> K{Compare R1 == R2};
          K -- Match --> L[Generate Signed 'Unlock' Command];
          L --> H;
          K -- No Match --> M[Activation Failed];
      end
      A --> C;
      F --> G;
  

---

Axis 3: Cross-Domain Application

Derivative 3.1: AgTech - Dynamic Licensing of Precision Farming Algorithms

• Enabling Description: A system for licensing algorithms on autonomous agricultural equipment. The "platform" is the tractor's ISO 11783 (ISOBUS) compliant control unit. A premium feature, such as a variable-rate seeding algorithm that adjusts seed placement based on real-time soil sensor data, is the "software." In "demonstration mode," the tractor operates using a fixed-rate, less efficient algorithm. To activate, the farmer uses a tablet interface to connect to the manufacturer's remote server. The "local licensee unique ID" is generated by combining the tractor's unique Vehicle Identification Number (VIN), the GPS-defined boundary (geofence) of the licensed field, and the farmer's account ID. The remote server verifies this data and returns a signed activation key valid only for the specified VIN and geofence. The tractor's control unit will only execute the premium algorithm when its GPS confirms it is inside the licensed boundary, reverting to demonstration mode otherwise.
• Mermaid Diagram:

  classDiagram
      direction LR
      class TractorECU {
          +String VIN
          +GPS_Coordinates currentPosition
          +String activeAlgorithm
          +verifyLicense(ActivationKey) bool
          +executeAlgorithm()
      }
      class FarmerTablet {
          +String farmerID
          +FieldGeofence fieldData
          +requestLicense()
      }
      class RemoteServer {
          +validateRequest(VIN, geofence, farmerID) bool
          +generateActivationKey() Key
      }
      class ActivationKey {
          +String licensedVIN
          +FieldGeofence licensedGeofence
          +Date expiryDate
          +Signature signature
      }
      FarmerTablet --|> RemoteServer : "requests"
      RemoteServer --|> ActivationKey : "generates"
      TractorECU --|> ActivationKey : "consumes"
  

Derivative 3.2: Medical Devices - Per-Patient Therapy Personalization

• Enabling Description: A system for licensing bespoke therapeutic algorithms on an implantable neurostimulator. The "platform" is the implanted device. The default "demonstration mode" provides a generic, low-amplitude stimulation pattern. A physician prescribes a custom stimulation algorithm ("software") tailored to a specific patient's condition. Using a secure, HIPAA-compliant portal, the physician (licensee) uploads the patient's anonymized case ID and the prescribed algorithm parameters to the device manufacturer's remote server. The "local ID" is the unique serial number of the implanted device, read by the physician's external programmer wand. The remote server validates the physician's credentials, logs the prescription, and generates an enabling key that encodes the specific algorithm parameters. The physician transmits this key to the implant via the programmer wand. The implant's firmware (the "mode switcher") verifies the key's signature and activates the personalized therapy ("use mode"). This ensures only validated, prescribed therapies are run on the device.
• Mermaid Diagram:

  sequenceDiagram
      participant Physician
      participant ProgrammerWand as Programmer
      participant Implant
      participant ManufacturerServer as Remote Server
  
      Physician->>Remote Server: 1. Login & Upload Prescription (Patient ID, Params)
      Physician->>Programmer: 2. Initiate implant communication
      Programmer->>Implant: 3. Read Implant Serial Number
      Implant-->>Programmer: 4. Return Serial Number
      Programmer-->>Physician: 5. Display Serial Number
      Physician->>Remote Server: 6. Request Enabling Key for Serial Number
      Remote Server->>Remote Server: 7. Validate & Generate Key
      Remote Server-->>Physician: 8. Provide Enabling Key
      Physician->>Programmer: 9. Load Enabling Key
      Programmer->>Implant: 10. Transmit Key to Implant
      Implant->>Implant: 11. Verify Key & Activate Personalized Therapy (Use Mode)
  

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Axis 4: Integration with Emerging Technology

Derivative 4.1: AI-Based Behavioral Attestation for Continuous Licensing

• Enabling Description: This disclosure describes a continuous, dynamic licensing system where the "match" is not a one-time event but an ongoing verification of user behavior. The "local licensee unique ID generating means" is a lightweight, trained neural network (e.g., a recurrent neural network or transformer) embedded in the software. This model generates a vector embedding based on real-time telemetry, including API call sequences, data access patterns, and even mouse movement dynamics. This embedding serves as a behavioral fingerprint. The remote server maintains a corresponding AI model that has been trained on the licensee's legitimate usage patterns. Periodically, the local embedding is sent to the remote server. The server compares the incoming vector with its expected profile using cosine similarity. If the similarity score drops below a pre-defined threshold (indicating anomalous behavior, possibly due to account sharing or malware), the remote server invalidates the session, and the local software reverts to a "limited functionality" mode pending manual re-authentication.
• Mermaid Diagram:

  graph TD
      subgraph Local Client
          A[User Interaction] --> B(Local RNN Model);
          B --> C[Generate Behavioral Embedding Vector];
      end
      subgraph Remote Server
          D[Store User's Profile Embedding]
          F(AI Comparison Engine)
          E[Receive Behavioral Embedding] --> F;
          D --> F;
          F -- Cosine Similarity > 0.95 --> G[Session Valid (Use Mode)];
          F -- Cosine Similarity <= 0.95 --> H[Session Invalid (Revert to Demo Mode)];
      end
      C --> E;
      H --> I[Send "Invalidate" Command to Local Client];
  

Derivative 4.2: Blockchain and NFT-Based License Management

• Enabling Description: A decentralized software licensing system using a public blockchain (e.g., Ethereum) and Non-Fungible Tokens (NFTs) conforming to the ERC-721 standard. The "remote licensee unique ID generating means" is a smart contract deployed by the software publisher. To acquire a license, a user pays cryptocurrency to a function on the smart contract, which then mints a unique NFT license and assigns it to the user's wallet address. This transaction is immutable and publicly verifiable. The "local software" integrates with a crypto wallet. To unlock "use mode," the software prompts the user to sign a message with their wallet's private key. The software (the "mode switcher") then verifies on-chain that (1) the signing wallet address is the owner of a valid license NFT, and (2) the signature is valid. License transfer is achieved simply by the user selling or transferring the NFT to another wallet.
• Mermaid Diagram:

  sequenceDiagram
      participant User
      participant Software
      participant Wallet
      participant Blockchain as Ethereum Smart Contract
  
      User->>Blockchain: 1. Purchase License (calls mint() function)
      Blockchain-->>User: 2. Mints and transfers License NFT to User's Wallet
      User->>Software: 3. Run software (starts in Demo Mode)
      Software->>User: 4. Prompt for license verification
      User->>Wallet: 5. "Connect Wallet"
      Software->>Wallet: 6. Request signature for challenge message
      Wallet-->>Software: 7. Return signed message + public address
      Software->>Blockchain: 8. Query: Does this address own a license NFT?
      Blockchain-->>Software: 9. Response: True
      Software->>Software: 10. Verify signature & Switch to Use Mode
  

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Axis 5: The "Inverse" or Failure Mode

Derivative 5.1: Graceful Degradation Licensing for Unreliable Networks

• Enabling Description: This system is designed for applications that operate in environments with intermittent or non-existent network connectivity (e.g., field research, maritime vessels). The license is based on a "lease" model. Upon initial registration with the remote server, the local software receives an enabling key that has a defined expiry time (e.g., 30 days). This key unlocks full "use mode." The software stores this lease token. If the device is offline, it continues to operate in full use mode. The "mode switcher" periodically checks the lease expiry. If the device can connect to the remote server before expiry, it automatically renews the lease for another 30 days. If the lease expires while the device is still offline, the software does not shut down but instead enters a pre-defined "graceful degradation mode." In this mode, core functionality remains (e.g., data viewing and local logging) but premium features requiring connectivity or heavy processing (e.g., cloud sync, advanced analytics) are disabled. This ensures the user is never left with a non-functional application due to connectivity issues, providing a safe failure state.
• Mermaid Diagram:

  stateDiagram-v2
      [*] --> Unregistered
      Unregistered --> Registered: Successful remote registration
      note on link: Receives 30-day lease token
  
      state Registered {
          direction LR
          [*] --> Full_Use
          Full_Use --> Full_Use: Check Lease: OK
          Full_Use --> Degradation_Mode: Check Lease: Expired
          Full_Use --> [*]: Network available, lease renewed
      }
  
      Degradation_Mode --> Registered: Network restored, re-register & renew lease
      note on link: Regains full functionality
  

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Combination Prior Art Scenarios with Open-Source Standards

1. Combination with FIDO2/WebAuthn: The system is implemented where the "local licensee unique ID" is a cryptographic assertion generated by a FIDO2-compliant authenticator (e.g., YubiKey, Windows Hello). The registration process involves a WebAuthn navigator.credentials.create() call where the public key credential is sent to the remote authority. Activation of the software's "use mode" requires a subsequent navigator.credentials.get() call, where the authenticator signs a server-provided challenge. The successful cryptographic verification of this signature acts as the "match," tying the software license directly to a hardware-backed, un-phishable user credential instead of user-entered data.

2. Combination with OAuth 2.0: The registration flow is modeled as an OAuth 2.0 authorization grant. The "remote licensee unique ID generating means" is the Authorization Server. The software acts as the client application. To switch to "use mode," the user is directed to the Authorization Server to log in and grant consent. The server returns an authorization code, which the client exchanges for an access token (the "enabling key"). Full functionality is enabled as long as the access token is valid and can be used to access protected backend resources. "Demonstration mode" is the state of the application before or after the token has expired.

3. Combination with Kerberos: In an enterprise environment, the system is integrated with a Kerberos Key Distribution Center (KDC). The "remote authority" is the KDC. To activate the software, the client authenticates with the KDC and receives a Ticket-Granting Ticket (TGT). It then requests a service ticket for the specific licensed software. The received service ticket is the "enabling key." The software ("mode switcher") decrypts the ticket to verify the user's identity and permissions, switching to "use mode." This allows licensing to be managed centrally via the existing enterprise identity and access management infrastructure.