Software Patent Invalidation: Prior Art Search, Reverse Engineering, and Source Code Analysis
Case Study · Invalidation Search

What If Software Source Code Could Invalidate a Patent?

Wissen transformed complex software source code into compelling prior art evidence, successfully challenging a patent on seamless audio/video communication.

Type: Invalidation Search
Industry: Communication
Published: May 20, 2026
communication ecosystem Image

The Client’s Challenge

A client sought support in invalidating a patent related to centralized communication platforms enabling seamless audio/video (A/V) communication functionality without requiring users to switch between applications.
The subject patent described a system architecture in which an existing application (parent application) integrates with an additional functional component (child component) that provides communication services such as audio and video calling. The claimed invention focused on enabling communication functionality within the existing application environment while maintaining a seamless user experience.

Audio video calling app image

The patent claims primarily covered:

    • Access by a parent application to functionalities implemented within a child functional component.
    • Capability determination by the child component to verify whether the parent application could support rendering operations.
    • Connection establishment with external communication servers by the child component on behalf of the parent application.
    • Provision of communication services by the child functional component to the parent application.
    • Seamless execution of communication services including connection establishment, capability checks, and service delivery communication workflows without requiring application switching.
CLIENT’S OBJECTIVE

Identify single-reference prior art for Section 102 anticipation – a significantly higher standard than obviousness under Section 103.

A single reference must disclose every claimed element – fragmented literature evidence does not suffice.

Higher bar than §103 - all elements must exist in one single reference

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They leave with opportunities they didn’t know existed.

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Wissen’s Out-of-the-Box Approach:

System Prior Art Through Reverse Engineering

  • Recognizing the limitations of conventional literature-based searching, the strategy evolved beyond traditional documentary prior art analysis.
  • To enable a broader and more technically grounded assessment of prior art evidence, the investigation expanded beyond a sole focus on published literature to include a system prior art analysis of real-world software systems that were:
  • Publicly available before the patent priority date
  • Commercially released and widely used
  • Demonstrative of the claimed functionality in practical implementation

Identifying Relevant System Prior Art

  • A focused technical investigation was conducted on communication software platforms released prior to the patent’s priority date.

  • However, publicly available documentation alone did not sufficiently disclose the internal implementation details required to address all claim limitations.

The analysis identified earlier versions of:

as potentially relevant system prior art candidates.

To overcome this limitation, static reverse engineering analysis was performed on publicly available Android application packages (APKs).

Our Methodology

Traditional Search Limitations
Identification of Real-World Software Systems
APK Acquisition and Static Decompilation
Source Code Level Functional Analysis
Claim Mapping Against System Features
Independent Public Evidence Corroboration
Single-Reference Anticipation Support
Traditional Search Limitations
  • Conventional literature search yields fragmented disclosures
  • Lack of implementation details in public documents
  • Multiple references needed
  • Stronger for obviousness (§103), not anticipation (§102)
Identification of Real-World Software Systems
  • Identify software systems released before priority date
  • Focus on commercially available and widely used applications
  • Evaluate relevance based on functionality and features
APK Acquisition and Static Decompilation
  • Obtain publicly available APK files (pre-priority date)
  • Perform static decompilation
  • Extract source code, resources, and configuration files
Source Code Level Functional Analysis
  • Analyze architecture, modules, and workflows
  • Identify implementation of key functionalities
  • Examine inter-component communication and logic
Claim Mapping Against System Features
  • Map identified functionalities to claim limitations
  • Establish how each claim element is met in the system
  • Document detailed claim charts and evidence
Independent Public Evidence Corroboration
  • Collect independent public evidence
  • Use release notes, user demos, documentation, videos, forums, etc.
  • Verify public availability before priority date
Single-Reference Anticipation Support
  • All claim elements disclosed within a single system
  • Strong support for §102 anticipation
  • Robust, verifiable, litigation-ready evidence
OUTCOME:

A single, publicly available software system with all claim element-backed by Source code level analysis and independent public evidence-providing strong §102 anticipation support for patent invalidation.

Reverse Engineering Methodology

The APK files corresponding to software versions released prior to the patent filing date were obtained from publicly accessible repositories.

The reverse-engineered analysis revealed that the relevant communication functionalities were already implemented and publicly accessible before the subject patent’s priority date.

Most importantly, the findings demonstrated that the identified software systems collectively disclosed all major claim elements within a single software ecosystem, strengthening the invalidation position under a Section 102 anticipation framework.

Technical Challenges Addressed Through System Prior Art Analysis

Challenge 1: Authorization and Authentication Between Functional Components

One of the key technical questions involved was determining whether the child functional component authenticated and authorized the parent application before enabling communication functionality such as video calling.

Solution

Static analysis of decompiled Skype Android application packages identified implementation of authentication and authorization workflows using Java built-in libraries and system-level communication mechanisms.

The analysis revealed:
  • User authentication workflows
  • Encoding and credential handling processes
  • Unique user identifier management
  • Controlled access to communication functionality

These findings demonstrated that access control mechanisms between functional components were already implemented in the identified system prior art prior to the patent’s filing date.

Audio video calling app image
Challenge 2: Capability Verification of the Parent Application

Another important challenge involved determining whether the child functional component verifies the parent application’s capability like “Camera, GPU, Display” capabilities to support communication rendering operations without requiring application switching.

Solution

Examination by the child functional block identified implementation of compatibility and hardware capability checks through evaluation of GPU capabilities, camera availability and display properties. Analysis further identified use of Android SurfaceView components to determine supported camera features and enable rendering of communication functionality within the parent application.

The analysis revealed:
  • Device GPU capability verification
  • Camera hardware availability verification
  • Mobile Display pixel capability verification to present video calling.

These mechanisms enabled the communication component to dynamically determine whether the application and device environment could support seamless communication rendering within the parent application interface.

The identified workflows directly addressed the corresponding patent claim limitations.

Audio video calling app image

Results & Business Impact

The final investigation successfully identified system prior art capable of addressing the subject patent claims through a technically supported and independently verifiable approach.

Key Outcomes

  • Identification of publicly accessible pre-priority date software systems implementing the claimed functionality.

  • Establishment of a stronger Section 102 anticipation-based invalidation position.

  • Successful demonstration of communication workflows through source code level evidence.

  • Validation of internal functional architecture absent from traditional documentation sources.

  • Strengthened client confidence through technically reproducible evidence.

Strategic Business Impact

By moving beyond conventional literature searching and incorporating system-level reverse engineering analysis, the investigation provided:

  • Stronger patent invalidation support
  • Reduced litigation and enforcement risk
  • Improved technical confidence in prior art positioning
  • Faster identification of enabling evidence
  • Broader prior art coverage beyond published literature

The approach demonstrated how combining software reverse engineering with independent public evidence can uncover highly relevant prior art that may remain undiscovered through conventional search methodologies alone.

Reverse-Engineering Methodology & Compliance Statement

  • The software analysis described in this case study was conducted solely for the purpose of identifying and evaluating publicly accessible technical features relevant to prior art assessment.

  • The examination was limited to static analysis techniques applied to publicly available versions of Skype Android application packages (APKs) released prior to the subject patent’s priority date.

  • Key compliance principles included:

Analysis restricted to publicly accessible software artifacts
No access to protected servers or confidential systems
No circumvention of security mechanisms
No software modification or redistribution
No interaction with proprietary backend infrastructure
Independent corroboration using publicly available sources
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