Secret Handshake Credential Revocation via Segmented Handles

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Solution Overview

Problem

Current secret handshake protocols lack an effective mechanism for credential revocation, which compromises user anonymity and allows unauthorized users to impersonate legitimate users, leading to malicious activities.

Innovation Solution

A system that utilizes reusable identification handles and credentials, provided by trusted third parties, with a revocation list to verify and reject compromised credentials, ensuring secure and anonymous communication by encrypting and anonymizing information exchanged during secret handshakes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If credentials are exchanged in encrypted and randomized form to preserve anonymity, then user anonymity is improved, but the ability to revoke compromised credentials deteriorates

Engineering Contradiction:
Improveuser anonymityVSAvoidcredential revocation capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The credential is segmented into multiple components: a public identifier (handle) that can be revoked and a secret key that remains private. The public key infrastructure separates the revocable public identifier from the non-revocable private key, allowing revocation without exposing the secret key. This segmentation enables the system to maintain anonymity while providing revocation capability through the public identifier.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A trusted third party (certificate authority) acts as an intermediary that issues certificates binding public identifiers to secret keys. This intermediary enables the revocation system by maintaining a revocation list of compromised public identifiers without requiring disclosure of the secret keys, thus preserving anonymity while enabling revocation through the intermediary's certificate validation service.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If unique labeling of credentials is implemented to enable revocation, then credential revocation capability is improved, but user anonymity deteriorates

Engineering Contradiction:
Improvecredential revocation capabilityVSAvoiduser anonymity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system applies different properties to different parts of the credential system: public identifiers have the quality of being revocable and traceable, while secret keys maintain the quality of being anonymous and untraceable. This local differentiation allows revocation of specific public identifiers without affecting the anonymity of the underlying users, as the secret keys remain protected and cannot be revoked or traced.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If revoked credentials are detected through comparison with revocation list, then security against unauthorized access is improved, but the complexity of the verification process increases

Engineering Contradiction:
Improveunauthorized access preventionVSAvoidverification process complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The revocation list is prepared in advance by the trusted third party, containing all compromised public identifiers before verification occurs. This preliminary preparation allows the verification process to simply compare against a pre-computed list rather than performing complex real-time analysis, reducing verification complexity while maintaining strong security against unauthorized access.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2200216B1Revocation of credentials in secret handshake protocols
Publication Date: 2014.11.26 SAP SE
  • EP2200216B1 patent drawingFigure 1
  • EP2200216B1 patent drawingFigure 2
  • EP2200216B1 patent drawingFigure 3

AI summary

According to a general aspect, a computer-implemented method for a first user to verify an association with a second user through a secret handshake protocol includes maintaining information about a reusable identification handle for the first user, where the information about the reusable identification handle is provided by a trusted third party, maintaining information about a reusable credential for the first user, where the information about the reusable credential is provided by a trusted third party, and maintaining information about a matching reference for verifying an association with another user, where the information about the matching reference is provided by a trusted third party. Information based on the reusable identification handle and based on the reusable credential is transmitted to a potential peer. First information based on a reusable identification handle for the second user is received, and second information based on a reusable credential for the second user is received. A first comparison of a combination of the first information and the second information is performed with the matching reference to determine whether the second user's credentials match the first users matching reference. A second comparison of the first information with information published on a revocation list is performed to determine whether the second user's credentials have been revoked from usage. Based on the first comparison and the second comparison, a determination is made whether or not to verify the association of second user with the first user.