摘要：In recent years clients generally outsource the sensitive information in any storage providers in order to access everywhere. There are so many intermediaries such as cloud providers to provide this. Personal health record is a promising approach for patient - centric model in which all the sensitive information including personal details will be outsourced to those third party providers. However there have been serious security issues will arise when any illegal parties tries to access those details. In order to ensure the privacy over the personal health information it is suggested to encrypt the data before outsourcing. Most significant challenges such as modularity issues in administrating the keys, disclosure of details, extensible in approaching the data and nullifying the data consumer details are turned to be a showstopper to achieve fine grained data mechanisms. In this paper we propose an innovative approach which makes sure of individual patient preferences and ensuring that patient values when PHRs stored in semi trusted servers. To overcome those significant challenges mentioned above we extended the attribute based encryption techniques to encrypt each patient's PHR file. By exploiting key policy and multi authority ABE data consumers are classified into various domains which will significantly reduces the key administrations. Also an efficient algorithm is used along with ABE which will Ensure the encryption of personal health details and provides high degree of privacy. Keywords: - Attribute Based Encryption, Key-policy, Multi-Authority, Central Authority
