Privacy-Preserved Search in mCL-PKE Based Secure Data Sharing over Public Clouds and Credential Trust Management through SMTP Communication

With the fast prominence of cloud computing architecture, public key cryptography exhibit certificate revocation problem and in the case of identity based encryption there exist a key escrow problem. Certificateless public key cryptography schemes now available are not properly sufficient because paring operation needs high amount of computational resources or they are vulnerable to partial decryption attacks. Sensitive data must be encrypted before sharing data over public cloud to maintain data confidentiality which make traditional data utilization invalid based on search of plaintext values. In order to resolve these problem, we proposing an improved Mediated certificateless public key encryption (mCL-PKE) scheme that does not use any pairing operations and solve the problem of sharing sensitive information in public clouds, also implement privacy-preserving searching over encrypted data with set of strict privacy axioms. On that public key encryption credential and key that used for encryption and decryption share through secure SMTP communication for maintaining trust management. In our system, the data owner needs to encode the same information encryption key different times, once for every client, utilizing the clients' open keys. To address this deficiency, we present an augmentation of the fundamental mCL-PKE plan. On the retrieval process, the cloud partially decrypts the encrypted data for the users and send the intermediate decryption keys to user by using secure SMTP communication. Our experiments on the real-world cloud data shows that our schemes are efficient for privacy-preserved search and trust management with mCL-PKE based secure storage also its solve the key escrow problem.