FABSS: Attribute-Based Sanitizable Signature for Flexible Access Structure

摘要

In the Electronic Health Record (EHR) system, digital signature is utilized to prevent the medical data from being tampered. However, users update their medical data frequently and have to sign these medical data from scratch after updating. Besides, traditional signature attests the identity of the individual signing the records, which leads to vast computation cost and the privacy leakage. In this paper, we obfuscate users identity information with attribute sets and introduce a semi-trusted participant-sanitizer to propose the Flexible Attribute-Based Sanitizable Signature (FABSS) scheme. We prove that our scheme is unforgeable under generic group model. Through comparison, the FABSS scheme not only reduces the users computation overhead, but also supports flexible access structures to implement expressively fine-grained access control.