Threshold multiparty multi‐randomness secure partially homomorphic encryption for data security in cloud

Abstract

Threshold cryptography is used to secure a cryptographic secret by dividing it into N shares and storing each claim on a diverse server. Any subgroup of t servers can use the secret without re‐making it. However, an adversary cannot recover the secret by compromising t − 1 servers. Homomorphic encryption operates directly on the ciphertext. In this study, a Threshold multiparty multi‐randomness secure partially homomorphic encryption (TM‐MR‐SPHE) algorithm is proposed to secure the outsourced data and perform multiplication and division operations on the ciphertext. The model is implemented in Eclipse IDE and AWS Toolkit for Eclipse and deployed in Amazon Elastic Beanstalk (EB) environment. This model is mainly used to secure the patient e‐health details and perform computation on outsourced data. The patient details are encrypted by the algorithm MR‐SPHE and uploaded in AWS (Amazon Web Service) S3 bucket. AWS identity and access management (IAM) creates the users' service and secret shares among multiple users in the EB environment. The proposed model performance is studied by comparing with other partially homomorphic Elgamal, Pailler, and Benaloh. This model achieves data integrity and confidentiality using the threshold multiparty with multi‐randomness secure partially homomorphic encryption.