Abstract: The advent of technology in healthcare ensures medical services to be provided more efficiently. Medical services are now provided through online assistance as well and the patients can maintain their health-related data in the cloud network. Personal health record (PHR) is deployed on the public cloud network. So, the data has to be stored on a central server which is guarded by the access control mechanism. But the data owners lose control on the data from the moment the data is stored in the server. Therefore, these systems do not fulfil the requirements of data outsourcing scheme. It is essential to ensure that the third party storing the data does not gain access to the plain data. In order to enhance security to the personal health records, attribute based encryption is used to encrypt the data before outsourcing it to the cloud. Personal health record users are divided into public and private domains. This will reduce the key management problem for owners and users. The proposed scheme will give personal health record owners full control of his/her data using Attribute based Encryption (ABE). In the proposed Key Policy Attribute Based Encryption (KP-ABE) scheme, the keys are only associated with the policy which have to be satisfied by the attributes to decrypt the data. Immense security and performance analysis based on computation time and key generation speed shows that the proposed scheme is highly efficient.

Keywords: Personal Health record, Attribute based Encryption, Key Policy Attribute Based Encryption.