A multi-watermarking protocol for health information management

Abstract

Buyer-seller watermarking protocols, combining digital watermarking and cryptographic tools, have become a feasible technique to guarantee piracy tracing. For securing health information management, watermarking protocols may be introduced to solve the problem of traitor tracing, i.e., tracing the physician who illegally discloses the patient’s health information. As a physician asks the health information system (HIS) for the intended patient’s health information, the relationship between the physician and HIS is similar to that between buyer and seller. By watermarking protocol, it can prevent physician from illegally distributing the patient’s health information over telemedicine environments in case remote physician and local physician exchange the patient’s health information and diagnosis views. While unauthorized health information is found, HIS can trace and accuse some physician who illegally releases the sensitive patient’s health information. However, buyer-seller protocols mentioned above cannot be applied to telemedicine systems directly because there is more than one physician involved. This paper proposes a multi-watermarking protocol to solve this problem, in which a well-defined single watermarking protocol is extended to form a novel multi-watermarking protocol. In addition, the proposed protocol adopts symmetric cryptosystem into watermark embedding so that the computation cost is lower than the protocols based on public key operation.