Cost-effective secure E-health cloud system using identity based cryptographic techniques

Nowadays E-health cloud systems are more and more widely employed. However the security of these systems needs more consideration for the sensitive health information of patients. Some protocols on how to secure the e-health cloud system have been proposed, but many of them use the traditional PKI infrastructure to implement cryptographic mechanisms, which is cumbersome for they require every user having and remembering its own public/private keys. Identity based encryption (IBE) is a cryptographic primitive which uses the identity information of the user (e.g., email address) as the public key. Hence the public key is implicitly authenticated and the certificate management is simplified. Proxy re-encryption is another cryptographic primitive which aims at transforming a ciphertext under the delegator A into another ciphertext which can be decrypted by the delegatee B. In this paper, we describe several identity related cryptographic techniques for securing E-health system, which include new IBE schemes, new identity based proxy re-encryption (IBPRE) schemes. We also prove these schemes' security and give the performance analysis, the results show our IBPRE scheme is especially highly efficient for re-encryption, which can be used to achieve cost-effective cloud usage.