DigitalSignature – Java Client Application

Overview

Digital Signature and Verification Tool is a Java-based desktop application designed to securely sign, verify, and manage digital documents.
The project implements cryptographic mechanisms for electronic signatures using RSA keys and X.509 certificates, ensuring document authenticity and integrity.

Key Features

• Digital signing and verification of PDF and DOCX documents
• RSA key pair generation and certificate handling
• Signature validation using public key cryptography and certificate verification
• Extraction of signer information (name, date of birth) from certificates
• Document preview, manipulation, and automatic saving of signed files
• Multithreaded operations for signature verification and email distribution of signed documents

Technologies Used

• Java SE (JavaFX) – User interface
• iText & Apache POI – PDF and DOCX file processing
• Java Security API – Cryptographic operations (RSA, X.509)
• JDBC & MySQL – Data persistence and signature logs

Purpose

Developed as a university project to demonstrate practical knowledge of:

• Java programming
• Cryptography
• Secure document handling

Author: Toni Krištić
Faculty Project – Digital Contract Signing and Verification Tool

University - Tehničko veleučilište u Zagrebu/University of Applied Science in Zagreb