Along with variant advantages, the cloud storage gained great attention from both industry and academics since 2007. However, it also brings new challenges in creating a secure and reliable data storage and access facility over insecure or unreliable service providers. The integrity of data stored in the cloud is one of the challenges to be addressed before the novel storage model is applied widely. In this paper, we propose a remote data integrity checking protocol based on HLAs and RSA signature with the support public verifiability. The support of public verifiability makes the protocol very flexible, since the user can commission the data possession to check the TPA.