eUICC Script Length Reduction via Local File Properties

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Solution Overview

Problem

As the number of profiles and their complexity increase in machine-to-machine (M2M) communications, the scripts used for remote provisioning of embedded Universal Integrated Circuit Cards (eUICC) become progressively larger and more complex, necessitating a method to reduce script length while maintaining compatibility with existing ISO 7816 APDU commands.

Innovation Solution

A method is introduced to prepare and process scripts for eUICC provisioning by replacing 'create file' commands with 'select file' commands if the required file properties are stored locally, allowing the eUICC to create files using its local store of file property data, thereby reducing script length without compromising compatibility with existing standards.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If 'create file' commands are included in provisioning scripts for eUICC, then files can be created on the secure element, but the script length increases and complexity increases

Engineering Contradiction:
Improvefile creation capabilityVSAvoidscript length
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The patent applies preliminary action by pre-storing file property data (such as file identifiers, access conditions, and file structure information) in the secure element before the provisioning script execution. When the script needs to create a file, it references the pre-stored property data instead of containing complete file creation commands, thereby reducing script length while maintaining file creation capability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts file property data from the provisioning script and stores it separately in the secure element's local memory. This separation allows the script to reference compact identifiers rather than containing complete file creation instructions, effectively removing redundant information from the script while preserving the ability to create files.

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If provisioning scripts include complete file creation commands, then files can be created with proper properties, but the script complexity increases

Engineering Contradiction:
Improvefile property accuracyVSAvoidscript complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

File property data including identifiers, access conditions, and structural information is pre-configured and stored in the secure element before script execution. This preliminary preparation ensures that files are created with accurate properties while keeping the provisioning script simple, as the script only needs to reference pre-defined property data rather than specifying all parameters.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If script length is reduced by removing create file commands, then transmission efficiency improves, but file creation capability may be compromised

Engineering Contradiction:
Improveprovisioning efficiencyVSAvoidfile creation reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The secure element is equipped with a local store of file property data that enables it to autonomously create files with correct properties when referenced by the provisioning script. This self-service capability allows the system to reduce script transmission while maintaining reliable file creation, as the secure element uses its own stored data to perform the actual file creation without needing complete commands from the script.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3023904B1Implicit File creation in APDU scripts
Publication Date: 2021.01.27 IDEMIA FRANCE SAS
  • EP3023904B1 patent drawingFigure 1
  • EP3023904B1 patent drawingFigure 2
  • EP3023904B1 patent drawingFigure 3~4

AI summary

A secure element (30) has a local store of file property data (50). A method of preparing a script to send to the secure element (30) to remotely provision a profile (31) at the secure element comprising preparing the script such that the script lacks a command to create a file if the local store of file property data (50) at the secure element includes file property data which can be used to locally create that file. A script may include an entry of reduced length which refers to the file to be locally created, such as a SELECT FILE command and an identifier of the file.