Digital Boarding House Rental Receipt Integrity Verification Using Ethereum Blockchain Hash Anchoring and Midtrans Payment Gateway

Abstract

This study develops a digital boarding-house receipt integrity verification mechanism by integrating the Midtrans payment gateway, SHA-256 hashing, and a smart contract on the Ethereum Sepolia test network. Operational data are stored in a MySQL database, while hashes of 17 receipt attributes are anchored on the blockchain. The system includes a Diagnostic Tamper Engine that uses inter-table relationships to help identify modified attributes. Evaluation consisted of six hash-recording transactions, four database-tampering scenarios, one control scenario, and 32 functional test scenarios. All recording transactions succeeded (6/6; 100%), consuming 576,856 gas per transaction with an average confirmation latency of 14.00 seconds. The average read-verification latency was 277.0 ms. All four tampering scenarios were detected and diagnosed (4/4; a 100% detection success rate), while the control scenario remained verified. All functional test scenarios also passed (32/32; 100%). These results indicate that the proposed mechanism can verify receipt integrity and identify changes under the controlled scenarios tested. The reported 100% rate is limited to these test cases and does not represent accuracy across all possible forms of tampering.