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Digital Signature App

Overview

Digital Signature App is a Windows Forms application developed in C# (.NET Framework 4.7.2) that demonstrates the process of creating digital signatures for documents using the ECDSA (Elliptic Curve Digital Signature Algorithm) cryptographic algorithm.

The application allows users to:

• Select a Microsoft Word document (.doc or .docx)
• Enter personal information (name and surname)
• Generate an ECDSA digital signature
• Create a PDF document containing signature information
• Export signature data into a .p7s file

This project was created for educational and research purposes to demonstrate the principles of digital signatures and document integrity verification.

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📋 Features

• ECDSA signature generation using the NIST P-256 curve
• SHA-256 hashing algorithm
• Simple Windows Forms graphical interface
• PDF generation with embedded signature information
• Signature export in .p7s format
• User identity information included in the generated document

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🛠 Technologies Used

• C#
• .NET Framework 4.7.2
• Windows Forms
• ECDSA Cryptography
• SHA-256
• iText 8
• Bouncy Castle

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🧭 Project Structure

DigitalSignatureApp/
│
├── MainForm.cs
├── MainForm.Designer.cs
├── Program.cs
├── App.config
├── DigitalSignatureApp.csproj
│
├── Properties/
│   ├── AssemblyInfo.cs
│   ├── Resources.resx
│   └── Settings.settings
│
└── packages/

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💡 How It Works

1. The user selects a Word document.
2. The user enters their name and surname.
3. The application generates an ECDSA key pair.
4. The selected document is hashed using SHA-256.
5. The document hash is digitally signed.
6. A PDF file is created containing:
   • Signer's information
   • Generated signature
7. A .p7s file containing signature data is exported.

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💾 Installation

Requirements

• Windows 10/11
• .NET Framework 4.7.2
• Visual Studio 2019 or newer

🚀 Build

git clone https://github.com/FullyRealist/DigitalSignatureApp.git

Open:

DigitalSignatureApp.sln

Restore NuGet packages and build the solution.

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🔁 Dependencies

• iText 8.0.3
• Portable.BouncyCastle 1.9.0
• Newtonsoft.Json 13.0.1

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⚠️ Disclaimer

This project is intended for educational purposes only.

The implementation demonstrates digital signing concepts but should not be considered a production-ready electronic signature solution. Additional certificate management, secure key storage, and signature validation mechanisms are required for real-world applications.

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© 2025. Odesa National Maritime University.