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EPRT: An Efficient Privacy-Preserving Medical Service Recommendation and Trust Discovery Scheme

As one of the essential applications of Health Information Technology (HIT), the eHealth system plays a significant role in enabling various internet medicine service scenes, most of which primarily rely on service recommendation or evaluation mechanism. To avoid privacy leakage, some privacy-preserving mechanisms must be adopted to protect raters' privacy and make evaluation trust reliable. To tackle this challenge, this paper proposes an efficient service recommendation and evaluation scheme, called EPRT, which is based on similarity calculation and trust discovery method. This scheme uses homomorphic encryption technology to encrypt the sensitive data and combines the threshold mechanism and double-trap mechanism to realize the security processing on the encrypted data, so as to ensure that the plaintexts of the final calculation results (e.g. recommendation value and evaluation truth) are only obtained by the authorized subject. Also, a detailed security analysis is conducted to show that the proposed EPRT scheme can achieve the expected security. In addition, a set of performance comparison results are carried out, demonstrating its effectiveness and accuracy.