Secure data deletion enables data owners to fully control the erasure of their data stored on local or cloud data centers and is essential for preventing data leakage, especially for cloud storage. However, traditional data deletion based on unlinking, overwriting, and cryptographic key management either ineffectiveness in cloud storage or rely on unpractical assumption. In this paper, we present SevDel, a secure and verifiable data deletion scheme, which leverages the zero-knowledge proof to achieve the verification of the encryption of the outsourced data without retrieving the ciphertexts, while the deletion of the encryption keys are guaranteed based on Intel SGX. SevDel implements secure interfaces to perform data encryption and decryption for secure cloud storage. It also utilizes smart contract to enforce the operations of the cloud service provider to follow service level agreements with data owners and the penalty over the service provider, who discloses the cloud data on its servers. Evaluation on real-world workload demonstrates that SevDel achieves efficient data deletion verification and maintain high bandwidth savings.

翻译：安全数据删除使数据所有者能够完全控制存储于本地或云数据中心数据的擦除，对于防止数据泄露至关重要，尤其适用于云存储场景。然而，传统的基于解链、覆写及密钥管理的数据删除方法在云存储中要么效果不佳，要么依赖不切实际的假设。本文提出SevDel——一种安全且可验证的数据删除方案：该方案利用零知识证明实现无需检索密文即可验证外包数据加密状态，同时基于Intel SGX保障加密密钥删除的可靠性。SevDel提供安全接口执行云存储数据的加密/解密操作，并采用智能合约约束云服务提供商的行为，确保其遵循与服务所有者签订的服务等级协议，并对泄露服务器端云数据的提供商实施惩罚。基于真实负载的评估表明，SevDel可实现高效的数据删除验证并维持高带宽节省。