Secure and Privacy‑Preserving Framework for Verifiable Data Deletion in Cloud Storage

Abstract

Public cloud settings make it easier for many people to share data and work together, but they also make it harder to delete data in a way that can be tracked and is safe. Users can't be sure that their deletion requests will be carried out honestly because cloud service providers may keep deleted data in secret files that can be used by people who aren't supposed to. To fix this problem, the Verifiable Deletion Protocol (VDUP) is created. It improves data security by separating deletion requests from credential replies by using uncertainty roles and uncertainty requests. This system makes sure that pre- and post-deletion verification can't be told apart. This way, cloud services can't figure out who sent the request or connect it to credentials. The protocol formally defines security properties and uses specific examples and security proofs to show that it can withstand backup attacks. A three-step process is built into the system: Anonymity Check 1 is used for data fingerprinting and deletion request filing before the deletion, and Anonymity Check 2 is used for validation after the deletion. In addition, an add-on encrypts stored data with AES and sets up access control rules that let users choose whether a file is public or private. Experiments show that this method reduces the time and effort needed to create credentials compared to current ones. It also finds unauthorized storage by comparing signatures between check steps, which makes users more confident in the deletion of data in the cloud.