Java Card Hybrid Package for Memory Optimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Java Card technology faces challenges in reducing the memory footprint of applications on smart cards due to limited memory resources, as existing optimization methods are inefficient and cannot effectively share resources between applet packages.

Innovation Solution

Converting Java Card applet packages into hybrid packages that function as both library and applet packages, allowing for the separation and removal of personalization code, and merging public resources to optimize memory usage without violating Java Card standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If applet packages are optimized by hand or refactoring byte code, then memory footprint is reduced, but the reduction is non-substantial and efficiency is limited

Engineering Contradiction:
Improvememory footprintVSAvoidoptimization efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The patent extracts personalization code into a separate removable package, allowing it to be removed after use. This extraction approach achieves substantial memory footprint reduction by eliminating unnecessary code rather than merely optimizing existing code structure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the applet package into multiple components including a permanent package and removable packages. This segmentation enables selective retention of essential code while removing personalization-specific code, achieving both memory reduction and functional integrity.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If personalization code is placed in a separate removable package, then memory footprint is reduced, but Java Card standard restrictions prevent library packages from containing applet packages

Engineering Contradiction:
Improvememory footprintVSAvoidpackage structure flexibility
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent creates a hybrid package structure that simultaneously functions as both a library package (for resource sharing) and an applet package (for application execution). This multi-functionality resolves the Java Card standard restriction by making the containing package capable of both roles.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines elements of library packages and applet packages into a composite hybrid package structure. This composite structure integrates the resource-sharing capabilities of library packages with the application-execution capabilities of applet packages, enabling both functions within the same package.

Inventive Principle:
Principle #40Composite materials

3Adaptability or versatility

If Shareable Interface is used to access SIO between packages, then resource sharing is enabled, but extra setup code increases communication overhead and application code size

Engineering Contradiction:
Improveresource sharing capabilityVSAvoidapplication code size
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges the applet package and library package into a single hybrid package, eliminating the need for inter-package communication through Shareable Interface. This merging removes the overhead of setup code and communication protocols while maintaining full resource sharing capability within the unified package structure.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3507689B1JAVA card application package used as a library package
Publication Date: 2020.07.08 THALES DIS FRANCE SA
  • EP3507689B1 patent drawingFigure 1
  • EP3507689B1 patent drawingFigure 2

AI summary

There is described a method use a java card applet package as a library package. The method proposes a way to extend export components of applet packages thus allowing them to be referred as library packages. By combining the cap file generated by a standard conversion of an applet package with the export file generated by a conversion which does not specify an applet it allows to obtain a hybrid package which can behave as both a library and an applet package.