The Blockchain‐Based Trustless Framework for Verifiable Secure Data Deletion

The verification and irreversible deletion of data stored in the cloud remains an unresolved problem, as there is no cryptographic proof of deletion, and cloud users must rely on the trustworthiness of the cloud service provider (CSP). In this paper, we introduce a blockchain‐enabled trustless protocol for secure and verifiable data deletion using advanced encryption standard (AES), InterPlanetary File System (IPFS), decentralized storage and Ethereum smart contracts. In addition, we have also used a hardware‐based approach for data deletion: triple‐pass overwrite with Merkle tree proof generation for HDDs, and cryptographic deletion with key destruction for SSDs. The deletion proofs are committed on‐chain, allowing public verification of deleted files without the involvement of any trusted third parties. The proposed system is implemented on the Ethereum Sepolia testnet.