Cloud security is one of the most important ongoing research, technology of the day to day life where the information stored in the cloud must be restricted to the unauthorized users and also it can be protected on the cloud server. In the existing Certificate less Public Key Encryption, it uses expensive pairing operations during each and every time, when a user wants to share the data in the public cloud. It is inefficient because it takes longer time to store and retrieve data in the public cloud. Hence, in this work it uses pairing free operations. The centralized public cloud used as both secure storage and also key generation centre. By considering the users public keys, the data administrator upload the sensitive information to the cloud. Finally authorized users decrypt the same encrypted information from the public cloud. This technique has greater performance and security than the earlier one.

Keywords: Certificateless encryption, Public key cryptography, Access Control