Certificateless public auditing for data integrity in the cloud

Due to the existence of security threats in the cloud, many mechanisms have been proposed to allow a user to audit data integrity with the public key of the data owner before utilizing cloud data. The correctness of choosing the right public key in previous mechanisms depends on the security of Public Key Infrastructure (PKI) and certificates. Although traditional PKI has been widely used in the construction of public key cryptography, it still faces many security risks, especially in the aspect of managing certificates. In this paper, we design a certificateless public auditing mechanism to eliminate the security risks introduced by PKI in previous solutions. Specifically, with our mechanism, a public verifier does not need to manage certificates to choose the right public key for the auditing. Instead, the auditing can be operated with the assistance of the data owner´s identity, such as her name or email address, which can ensure the right public key is used. Meanwhile, this public verifier is still able to audit data integrity without retrieving the entire data from the cloud as previous solutions. To the best of our knowledge, it is the first certificateless public auditing mechanism for verifying data integrity in the cloud. Our theoretical analyses prove that our mechanism is correct and secure, and our experimental results show that our mechanism is able to audit the integrity of data in the cloud efficiently.