1Mr. JAHANGEER PASHA, 2G. VAISHNAVI, 3K. MANASA, 4G. ABHIRAM 03 05 Cloud computing has become a dominant paradigmfor storing and managing large volumes of data dueto its scalability flexibility and cost efficiencyHowever outsourcing data to remote cloud serversresults in the loss of direct control over data raisingcritical concerns regarding data integrity securityand trust Traditional auditing mechanisms rely oncentralized ThirdParty Auditors TPAs whichintroduce risks such as single points of failure lackof transparency and potential collusion with cloudproviders To address these challenges this projectproposes a BlockchainBased Decentralized PublicAuditing BDPA system for secure cloud storageverification The system leverages blockchaintechnology to eliminate dependency on centralizedauditors by enabling decentralized verificationthrough smart contracts Users generateauthentication tags using identitybasedcryptography and upload data to the cloud Duringauditing a decentralized commitreveal mechanismgenerates random challenges and the cloud serverresponds with proof of data possession Theblockchain network verifies this proof withoutaccessing actual data ensuring privacypreservation Audit results are permanentlyrecorded on the blockchain providing transparencyand tamperproof logging The proposed systemimproves reliability scalability and resistanceagainst malicious attacks while maintainingefficient verification with minimal communicationoverhead Experimental evaluation demonstratesthat the system effectively prevents data tamperingensures secure auditing and enhances trust in cloudstorage services Overall integrating blockchainwith cloud auditing provides a robustdecentralized and privacypreserving solution formodern data integrity verification Copyright (c) Journal of Science Engineering Technology and Management Science. All rights reserved 2026