PROJECT TITLE :

Full Verifiability for Outsourced Decryption in Attribute Based Encryption - 2017

ABSTRACT:

Attribute based mostly encryption (ABE) may be a in style cryptographic technology to shield the safety of users’ knowledge. But, the decryption price and ciphertext size limit the appliance of ABE in practice. For most existing ABE schemes, the decryption cost and ciphertext size grow linearly with the complexity of access structure. This is undesirable to the devices with limited computing capability and cupboard space. Outsourced decryption is taken into account as a possible methodology to reduce the user's decryption overhead, that allows a user to outsource a giant variety of decryption operations to the cloud service provider (CSP). However, outsourced decryption cannot guarantee the correctness of transformation done by the cloud, therefore it's necessary to check the correctness of outsourced decryption to confirm security for users’ information. Current analysis mainly focuses on verifiability of outsourced decryption for the authorized users. It still remains a challenging issue that how to ensure the correctness of outsourced decryption for unauthorized users. In this paper, we propose an ABE scheme with verifiable outsourced decryption (referred to as full verifiability for outsourced decryption), that can simultaneously check the correctness for reworked ciphertext for the authorized users and unauthorized users. The proposed ABE scheme with verifiable outsourced decryption is proved to be selective CPA-secure in the standard model.