Unlinkable Digital Signature-Equivalent for Privacy-Preserving Attribute Verification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing digital attribute assertion systems fail to ensure unlinkability of attribute assertions provided to multiple service providers, compromising user privacy and anonymity, as service providers can collude to gather additional information about the attribute asserter.
Innovation Solution
A method for creating an unlinkable digital signature-equivalent of an assertion message using a one-way transformation of the digital signature, involving a first random number generated by the attribute assertion device and a challenge provided by the service provider, without sharing a secret cryptographic key, allowing verification by the service provider using a bilinear map and public key of the attribute provider.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the same attribute message is used with several service providers, then verification of attribute authenticity is achieved, but service providers can collude to determine characteristics of the attribute asserter, compromising privacy and anonymity
Solution Approach 1:
The patent segments the verification process by introducing unlinkable signature equivalents that separate the authentication function from the identifying function. Each service provider receives a transformed signature that verifies authenticity but cannot be linked to the original attribute asserter, thus segmenting the information flow to protect privacy while maintaining verification reliability
Solution Approach 2:
The patent introduces an intermediary transformation process that converts the original digital signature into an unlinkable signature equivalent. This intermediary step acts as a mediator that preserves the verification capability while removing the linking information, allowing service providers to verify attributes without accessing identifying characteristics of the attribute asserter
2Reliability
If a digital signature is directly provided to service providers, then attribute authenticity can be verified, but the attribute asserter's characteristics can be determined through collusion among service providers
Solution Approach 1:
The patent extracts the harmful linking information from the digital signature by transforming it into an unlinkable signature equivalent. The transformation process takes out the identifying characteristics that would allow service providers to determine attribute asserter characteristics, while retaining the essential verification functionality needed for attribute authentication
Solution Approach 2:
The patent converts the potential harm of signature exposure into a benefit by using the signature transformation process to create unlinkable equivalents. The original signature's verification capability is preserved and enhanced, while the risk of data compromise is eliminated through the unlinkable transformation that prevents collusion-based attacks
Data Source
AI summary
A method for operating an attribute assertion device having a processor and memory to create an unlinkable digital signature-equivalent of an assertion message that is verifiable—by a service provider receiving the unlinkable digital signature-equivalent—as being generated from a digital signature of a known attribute provider having a public key PKAP. Operating the processor of the attribute assertion device to transform a digital signature of the attribute message into an unlinkable digital signature-equivalent using a one-way transformation of the signature, with the transformation process using a random value generated by the attribute assertion device and a challenge provided by the service provider.