🔐 FintechEncryption

🚀 Enterprise Hybrid Encryption Library for Secure FinTech Application/Api

FintechEncryption is a lightweight .NET library that provides secure data encryption and decryption using Hybrid Cryptography.

It combines:

• 🔑 AES-256-GCM for fast symmetric encryption
• 🔐 RSA-2048 OAEP for secure key exchange
• ✍️ SHA256 Digital Signature for message integrity

This approach is widely used in banking systems, payment gateways, and fintech APIs.

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✨ Features

✔ Hybrid Encryption (AES + RSA) ✔ AES-256-GCM authenticated encryption ✔ RSA-2048 OAEP key exchange ✔ SHA256 Digital Signature verification ✔ Secure random key generation ✔ Lightweight and dependency minimal ✔ Multi-framework support ✔ Easy integration into existing APIs

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📦 Supported Frameworks

This library supports multiple .NET frameworks:

Framework	Supported
.NET Framework 4.8	✅
.NET Standard 2.0	✅
.NET 6 / 7 / 8	✅
ASP.NET MVC	✅
ASP.NET Core	✅
Console Applications	✅

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📥 Installation

Install via NuGet Package Manager

Install-Package FintechEncryption

or using .NET CLI

dotnet add package FintechEncryption

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🔑 Hybrid Encryption Architecture

🔐 Security Design

The library follows industry-standard cryptographic practices:

Component	Algorithm
Data Encryption	AES-256-GCM
Key Exchange	RSA-2048 OAEP
Signature	SHA256withRSA
Random Generation	SecureRandom

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🔁 Secure Communication Use Case

A common real-world scenario is secure communication between two systems, such as:

• 🏦 Bank ↔ Payment Gateway
• 🏢 FinTech Platform ↔ Partner API
• 🛒 Merchant System ↔ Payment Processor

Each system generates its own RSA key pair, then exchanges public keys to enable secure encrypted communication.

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🔑 Step 1: Generate Key Pairs

Each system generates its own RSA key pair.

System A (Sender)

var systemAKeys = KeyGenerator.GenerateRSAKeys();

string systemAPublicKey = systemAKeys.PublicKey;
string systemAPrivateKey = systemAKeys.PrivateKey;

System B (Receiver)

var systemBKeys = KeyGenerator.GenerateRSAKeys();

string systemBPublicKey = systemBKeys.PublicKey;
string systemBPrivateKey = systemBKeys.PrivateKey;

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🔄 Step 2: Exchange Public Keys

Both systems securely exchange public keys.

System	Shares	Keeps Secret
System A	Public Key	Private Key
System B	Public Key	Private Key

Example:

System A → sends PublicKeyA to System B  
System B → sends PublicKeyB to System A

Private keys must never be shared.

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🔒 Step 3: System A Encrypts Data

System A encrypts the payload using:

• its private key (for signing)
• System B's public key (for encrypting AES key)

var encryptionService = new EncryptionService();

string encryptedPayload = encryptionService.EncryptData(
    plainTextData,
    systemAPrivateKey,
    systemBPublicKey
);

Encrypted data can now be sent over:

• REST APIs
• Message queues
• Webhooks
• Secure channels

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🔓 Step 4: System B Decrypts Data

System B decrypts the message using:

• its private key (to decrypt AES key)
• System A's public key (to verify signature)

var decryptionService = new DecryptionService();

string decryptedPayload = decryptionService.DecryptData(
    encryptedData,
    systemBPrivateKey,
    systemAPublicKey
);

System B can now safely process the data.

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🔐 Security Guarantees

This hybrid encryption model provides:

Security Property	Description
🔒 Confidentiality	Only the receiver can decrypt the message
✍️ Integrity	Message cannot be altered without detection
👤 Authentication	Confirms the sender's identity
🔑 Secure Key Exchange	AES key protected by RSA

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📡 Communication Flow

System A                           System B
---------                         ---------

Generate KeyPair A                Generate KeyPair B

PublicKeyA  -------------------->  PublicKeyA received
PublicKeyB  <--------------------  PublicKeyB shared

Encrypt using:
PrivateKeyA + PublicKeyB

Encrypted Payload  ------------->  Receive Payload

                                   Decrypt using:
                                   PrivateKeyB + PublicKeyA

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The payload is encrypted before transmission to ensure high-level API security.

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⚠️ Exception Handling

FinTechEncryption uses a custom exception EncryptionException for all encryption and decryption related errors.
Applications using the library should catch this exception to safely handle failures.

Example Usage

using FinTechEncryption;

try
{
    var decryptionService = new DecryptionService();

    string decrypted = decryptionService.DecryptData(
        encrypted,
        receiverPrivateKey,
        senderPublicKey
    );

    Console.WriteLine("Decrypted Data: " + decrypted);
}
catch (EncryptionException ex)
{
    Console.WriteLine("Encryption operation failed: " + ex.Message);
}
catch(Exception e)
{
    Console.WriteLine("Exception Error: " + e.Message);
}

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🚀 When To Use This Library

Use FintechEncryption when building:

• FinTech APIs
• Payment gateway integrations
• Secure partner APIs
• Banking systems
• Sensitive data exchange services
• Enterprise API platforms

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🤝 Contributing

Contributions are welcome!

Steps:

1. Fork the repository
2. Create a feature branch
3. Commit your changes
4. Open a Pull Request

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📜 License

This project is licensed under the MIT License.

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⭐ Support

If you find this project useful:

⭐ Star the repository 🐛 Report issues 💡 Suggest improvements

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🔗 Keywords

dotnet encryption
hybrid encryption
aes rsa encryption
fintech security
secure api encryption
api payload encryption

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