This document proposes a privacy-preserving authentication protocol for shared authority-based cloud computing. It discusses security and privacy issues with data sharing among users in cloud storage. The proposed protocol uses a shared authority-based privacy preservation authentication protocol (SecCloud) to address privacy and security concerns for cloud storage. It also uses SecCloud+ to remove data de-duplication. The protocol aims to provide scalability, integrity checking, secure de-duplication, and prevent shoulder surfing attacks during the authentication process in cloud computing.