Permanent Public SIP Address Generation via Hash Function

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing IMS network authentication process requires modification of the private identity IMPI into a public address format for direct network access, leading to additional costs and proxy overload, as the network cannot address the secure element directly without disclosing the private identity.

Innovation Solution

A method is introduced to generate a permanent public SIP address associated with the private identity IMPI using a non-reversible and collision-free hash function, such as SHA-256, allowing the IMS network to address the secure element without revealing the private identity, enabling direct communication and updates via OTA.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the private identity IMPI is modified into a public address format for direct network access, then the network can address the secure element directly, but the private identity is disclosed and additional proxy infrastructure is required

Engineering Contradiction:
Improvenetwork accessibilityVSAvoidprivate identity secrecy
Core Design Contradiction:
Ease of operationVSLoss of information

Solution Approach 1:

A public identifier (PID) is introduced as an intermediary between the private identity (IMPI) and the network. The PID is derived from the IMPI through a one-way function, allowing the network to address the secure element without knowing or disclosing the private identity. This mediator enables direct network access while preserving secrecy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of using the private identity directly, a copy or derivative of it (the public identifier PID) is used for network communication. The PID contains sufficient information for network addressing but does not reveal the original IMPI, allowing the network to operate with a simplified public interface.

Inventive Principle:
Principle #26Copying

2Ease of operation

If a proxy infrastructure is added to enable direct addressing, then network accessibility is improved, but operational costs and system complexity increase

Engineering Contradiction:
Improvedirect addressing capabilityVSAvoidproxy infrastructure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The secure element itself generates and manages the public identifier (PID) derivation from its private identity (IMPI) using a one-way function. This self-service mechanism eliminates the need for complex proxy infrastructure, as each secure element can independently create its own public identifier for network communication.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system changes the parameter used for network addressing from the private identity format to a public identifier format derived through cryptographic transformation. This parameter change enables direct addressing without requiring additional proxy infrastructure, simplifying the overall system architecture.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2532147B1Method for generating a permanent public SIP address associated with a private identity on an IMS network
Publication Date: 2015.08.19 THALES DIS FRANCE SA
  • EP2532147B1 patent drawingFigure 1
  • EP2532147B1 patent drawingFigure 2

AI summary

The invention relates to a method for generating a permanent public SIP address associated with a private identity on an IMS network. According to the invention, the method consists of applying, to the private identity, a one-to-one, non-reversible and collision-free function in order to obtain the permanent public SIP address. The invention enables the ISIM of an end point to be directly addressed.