Recommender Privacy Preserving Reputation Based Medical Services Scheme Using a Variant of ElGamal

Abstract

Reputation based schemes are gaining popularity in all spheres of the service industry. In this paper, we have proposed a privacy preserving secure recommender reputation based medical services system. This system enables medical users to get a reputation score of a medical service provider before engaging in any services. Further, alongside the result of the query for the reputation score of the specific medical service provider in question, the scheme also avails reputation scores of other relevant medical service providers. This kind of approach ensures that the medical user has some apriority information of the quality of service to expect from the medical service providers and has a chance to choose the one with the best reputation from the ones presented. Our proposed scheme uses a variant of the ElGamal cryptosystem to preserve the anonymity of the medical user making the query. Further, our scheme too ensures the privacy of the reputation scores submitted by the medical users who give their reputation scores of the medical service providers queried.