CipherFlow System

📝 Description

CipherFlow System is a Windows console application written in C that provides file encryption, file decryption, task scheduling, and secure TCP file transfer.
The system is based on a custom password-driven algorithm combining with a dynamic versioning mechanism, a non-linear permutation process, and a reliable file transfer protocol built with Winsock.

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📦 Features

• 🔒 File Encryption
  Encrypts one or multiple files using a password and a version.
• 🔓 File Decryption
  Decrypts encrypted files using the correct password and version.
• ⏳ Scheduled Encryption
  Schedule file encryption at a specific date and time.
• ⏳ Scheduled Decryption
  Schedule file decryption at a specific date and time.
• 📤 File Transfer (New in v1.3)
  Securely send files to another computer over TCP.
• 📥 File Reception (New in v1.3)
  Receive files from another computer through CipherFlow's built-in transfer protocol.
• 🌐 Multilingual Support
  Dynamic language switching (French / English)
• 🛡️ Safety Protection
  Prevents accidental file overwriting or deletion.

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💻 Technical Features

• Dynamic handling of multiple files with secure memory allocation
• Input validation (password, version, IP address, Port, and file paths)
• Scheduling system based on system date and time
• Password strength estimation based on character repetition
• Reliable TCP file transfer using Winsock
• Guaranteed data transmission with send_all() and recv_all()
• Automatic transfer progress display
• Dual-language display (EN / FR)

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🔐 Encryption Mechanism

The system relies on a custom algorithm composed of several steps:

• Key generation from password and version
• Data transformation based on the generated key
• Non-linear permutation using version-adjusted key values

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🌐 File Transfer Protocol

CipherFlow v1.3 introduces a built-in TCP file transfer system.

Features include :

• Reliable TCP communication
• Automatic sender/receiver connection
• Guaranteed transmission of all file data
• Transfer progress monitoring
• Support for files of virtually any size
• Network error handling
• Automatic reconstruction of the received file

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🎨 Console Interface

• Progressive text rendering
• Color effects and “Matrix-style” animations
• Windows alerts using MessageBox()
• Dedicated network connection interface
• Real-time transfer progress
• Improved console layout

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🧠 Learning Objectives

This project helps practice:

• File handling in C (fopen, fclose, getc, fprintf)
• Dynamic memory management (malloc, calloc, free)
• Use of struct for data organization
• Console UI + Windows popups integration
• TCP socket programming with Winsock
• Client/Server architecture
• Reliable file transfer protocol implementation

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⚙️ Technologies

• App : Console application (CLI)
• Language: C
• Compiler: GCC (MSYS2/MinGW-w64)
• Operating System: Windows
• Networking: Winsock (TCP)
• Windows API: User32, Shell32
• Resource System: Windows Resource Compiler (.rc)

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🛠️ Build & Compilation

Bash
windres resource.rc -O coff -o CipherFlow.res

gcc main.c function.c CipherFlow.res -o FILE_CRYPTER.exe -luser32 -lws2_32 -lshell32

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▶️ Execution

Bash
./FILE_CRYPTER.exe

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📋 Requirements

• Windows 10 or later
• MSYS2 (for compilation)
• GCC (MinGW-w64)
• Windows SDK (Resource Compiler)

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⭐ Use Cases

1️⃣ Personal Data Protection :

• Secure sensitive files (passwords, private documents, confidential data)
• Encrypt data before storage or sharing

2️⃣ Security Automation :

• Schedule encryption/decryption tasks
• Reduce manual intervention

3️⃣ Data Loss & Leak Prevention :

• Protect files from unauthorized access
• Secure files before transfer

4️⃣ Secure File Transfer :

• Send files securely between Windows computers
• Transfer encrypted files over a local network
• Share large files through CipherFlow's built-in protocol

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📁 Supported File Types

All file types are supported, including binary and text files.

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⚠️ Important Notes

• Works on Windows only.
• Correct password and version are required for decryption.
• Scheduled encryption works even if the file does not exist yet.
• Sender and receiver must use the same TCP port.
• File transfer requires an network connection between the device.
• Encrypted files use the .cflow extension.

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🔥 Future Improvements

• Transfer authentication
• End-to-end encrypted communication
• Transfer resume support
• Multi-file transfer
• Graphical User Interface (GUI)
• Logging and monitoring system

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📚 Documentation

For a detailed explanation on how to use:

• 👉 View Full User Guide

📄 License

This project is licensed under the

🌍 FRENCH VERSION