AuditChain Backend

AuditChain is a cryptographically secure banking backend designed for absolute transaction integrity. It implements a tamper-evident audit ledger using SHA-256 hash-chaining at the database layer, combined with AI-powered forensic auditing.

Core Features

• SHA-256 Hash Chaining: Every transaction (Insert/Update/Delete) is cryptographically linked to the previous state via MySQL triggers, creating an immutable ledger.
• Tamper Detection: An internal verification engine that performs recursive chain sweeps to detect unauthorized database modifications.
• AI Forensic Integration: Leverages Google Gemini 2.5-flash to analyze audit breaches and provide human-readable security summaries.
• Role-Based Security: Secure JWT authentication with distinct permissions for USER, ADMIN, and AUDITOR.
• Genesis Block Handling: Robust support for system initialization and genesis hash verification.

Tech Stack

• Framework: Spring Boot 3+
• Database: MySQL 8.0 (utilizing JSON functions and AFTER triggers)
• Security: Spring Security + JJWT
• AI Engine: Gemini AI API
• ORM: Spring Data JPA / Hibernate

Prerequisites

• Java 17 or higher
• MySQL 8.0+
• Maven

Setup & Installation

1. Database Setup:

   • Create a database named AuditChain.
   • Execute the SQL scripts in setup_database.sql to initialize tables and install the unified cryptographic triggers.

2. Configuration:

   • Create a file named src/main/resources/application-local.properties (this file is gitignored).
   • Add your local credentials:

     spring.datasource.password=YOUR_DB_PASSWORD
     jwt.secret=YOUR_LONG_RANDOM_SECRET_KEY
     gemini.api.key=YOUR_GEMINI_API_KEY

3. Build & Run:

   mvn clean install
   mvn spring-boot:run

Security Architecture

The system's integrity is enforced by Database Triggers. Any change to the accounts table automatically generates a new hash in the audit_log table: row_hash = SHA2(CONCAT(tableName, operation, recordId, oldData, newData, changedBy, changedAt, prevHash), 256)

If any manual modification is made to the database bypassing the application layer, the chain breaks, and the Auditor Verification Service will flag the exact record that was tampered with.

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© 2026 AuditChain Labs | Secured by Mathematics.