SPHINXHybridKey

Introduction

This project is dedicated to the world community as an Open-source Post-quantum blockchain layer 1 project, means anyone can join and contribute based on his/ her passion and skills. SPHINX is a blockchain protocol designed to provide secure and scalable solutions in the post-quantum era.

This repository contains code for the SPHINXKey project, which is a Generating Key, Master key, and Address module for the SPHINX blockchain framework.

Components

In the thrilling era of quantum computers, where we find ourselves in a Super Position between classical and quantum realms, the choice of a hybrid key exchange scheme combining X25519 and Kyber768 holds immense significance. Let's explore why this combination is the perfect fit.

1. Embracing the Best of Both Worlds: X25519, a battle-tested and widely adopted algorithm, provides a solid foundation of proven security and efficient key generation. On the other hand, Kyber768 represents the cutting-edge of post-quantum cryptography, designed to resist attacks from powerful quantum computers. By combining these two exceptional algorithms, we enter a "Super Position" where we benefit from the strengths of both classical and quantum-resistant cryptography.

2. Inspiration from Tech Giants: The widespread adoption of X25519 and Kyber768 by the larger tech community serves as our guiding light and inspiration. These algorithms have garnered trust and confidence from experts and industry leaders, paving the way for their integration into our hybrid scheme. By following in the footsteps of these role models, we embrace a solution that is not only innovative but also aligns with industry best practices.

In this era of immense technological possibilities, the combination of X25519 and Kyber768 in a hybrid key exchange scheme symbolizes our readiness to face the challenges presented by quantum computing. It demonstrates our commitment to leverage the proven track record of X25519 and the promising resilience of Kyber768. Together, these algorithms empower us to navigate the quantum landscape with confidence, ensuring the security and longevity of our cryptographic systems.

The Purpose

The combination of X25519 and Kyber768 in a hybrid key exchange is designed to harness the unique strengths of each algorithm, resulting in a more robust and versatile cryptographic solution.

X25519 is an elliptic curve Diffie-Hellman (ECDH) key exchange algorithm based on the Curve25519 curve. It offers several advantages, including efficient key generation, compact key sizes, and resilience against various common attacks. X25519 excels in terms of both performance and security, making it an ideal choice for key exchange operations.

On the other hand, Kyber768 is a post-quantum key encapsulation mechanism (KEM) that addresses the security challenges posed by quantum computers. It is based on the Learning With Errors (LWE) problem and provides strong resistance against attacks by quantum adversaries. Kyber768 offers a robust security guarantee in a post-quantum computing era when traditional cryptographic schemes may be vulnerable.

By combining X25519 and Kyber768 in a hybrid key exchange, we can leverage the efficiency and security benefits of X25519 while also incorporating the post-quantum resistance of Kyber768. This hybrid approach enables we to strike a balance between immediate performance needs and long-term security considerations. It is particularly advantageous in scenarios where both efficient key exchange and protection against future quantum threats are crucial.

Description and logic;

• X25519 given 128-bit security level
• Kyber-768 given (equal AES-192) mean 192-bit security level

If we merged them it means we will achieve security level nearly 320-bytes, its lightweight enough.

SPHINXKey Namespace

The SPHINXKey namespace provides functions for generating key pairs, calculating addresses, and printing key information. It relies on functionality from other included headers such as Hybrid_key.hpp and Hash.hpp.

Functions

• The code defines a function called performX25519KeyExchange that performs the X25519 key exchange given a private key, public key, and a buffer to store the shared key.

• It defines a structure called HybridKeypair, which holds the merged key pair consisting of a Kyber768 key pair and an X25519 key pair, as well as PKE key pair, and a random number generator.

• The function generate_hybrid_keypair generates a hybrid key pair by generating a Kyber768 key pair, an X25519 key pair, and a PKE key pair using appropriate functions. It returns the generated hybrid key pair.

• The function deriveMasterKeyAndChainCode is used to derive a master private key and chain code from a given seed using the HMAC-SHA512 function. It returns the derived master private key and chain code as a pair.

• There are several utility functions defined, such as deriveKeyHMAC_SHA512 to derive a key using HMAC-SHA512, hashSWIFFTX512 to calculate the SWIFFTX-512 hash of data, and generateRandomNonce to generate a random nonce.

• The function deriveKeyHKDF derives a key using the HKDF (HMAC-based Key Derivation Function) algorithm with SHA256 as the default hash function.

• The function hash calculates the SWIFFTX-256 hash of a given input.

• The function generateKeyPair generates a random private key and calculates the corresponding public key by hashing the private key.

• The function generateAddress generates an address from a given public key by hashing the public key and taking the first 20 bytes of the hash.

• The function requestDigitalSignature requests a digital signature for a given data using the provided hybrid key pair.

• The functions encryptMessage and decryptMessage are used to encrypt and decrypt a message, respectively, using the Kyber768 KEM (Key Encapsulation Mechanism).

• The functions encapsulateHybridSharedSecret and decapsulateHybridSharedSecret are used to encapsulate and decapsulate a shared secret using the hybrid KEM, which combines X25519 and Kyber768.

This code provides a set of functions and structures to support hybrid key generation, key exchange, encryption, decryption, and other cryptographic operations.

The interaction and collaboration between Hybrid_Key.hpp and SPHINXKey can be summarized as follows:

Interactions between SPHINXKey and SPHINXHybridKey Namespaces

1. SPHINXKey Namespace interacts with the SPHINXHybridKey Namespace by calling the function generate_hybrid_keypair from the SPHINXHybridKey namespace. This function generates the hybrid keypair and its corresponding private and public keys.

2. The function SPHINXKey::generateAddress uses the SPHINXHybridKey::SPHINXHash::SPHINX_256 function to hash the public key and generate an address based on the hash. This address is used for smart contract identification.

3. In SPHINXHybridKey::generate_hybrid_keypair, Kyber768 and X25519 keypairs are generated. The function also derives a master private key and chain code using HMAC-SHA512 from a seed value and then derives private and public keys from the master key and chain code using HMAC-SHA512.

4. The SPHINXHybridKey namespace provides functions to encrypt and decrypt messages using Kyber768 for KEM (Key Encapsulation Mechanism).

5. The SPHINXHybridKey::performX25519KeyExchange function performs the X25519 key exchange.

6. The SPHINXHybridKey namespace also includes functions to encapsulate and decapsulate shared secrets using the hybrid KEM, combining the results of Kyber768 and X25519.

Combined Usage: The combined usage of SPHINXKey and SPHINXHybridKey allows for the generation of secure hybrid keypairs that leverage the strengths of both Kyber768 and X25519 cryptographic algorithms. The hybrid keypairs can be used for various cryptographic purposes, including encryption, decryption, and key exchange, making it a versatile and robust cryptographic solution.

The interaction between Key.cpp and Hybrid_key.hpp involves calling functions defined in Hybrid_key.hpp from Key.cpp to perform various operations related to hybrid key generation, key exchange, address generation, and public key calculation. Hybrid_key.hpp provides the necessary functions and data structures to support these operations, and Key.cpp utilizes them to implement the desired functionality.

Note

Every code in the repository is a part of the SPHINX blockchain algorithm, which is currently in development and not fully integrated or extensively tested for functionality. The purpose of this repository is to provide a framework and algorithm for the digital signature scheme in the SPHINX blockchain project.

As the project progresses, further updates and enhancements will be made to ensure the code's stability and reliability. We encourage contributors to participate in improving and refining the SPHINXBlock algorithm by submitting pull requests and providing valuable insights.

We appreciate your understanding and look forward to collaborative efforts in shaping the future of the SPHINX blockchain project.

Getting Started

To get started with the SPHINX blockchain project, follow the instructions below:

1. Clone the repository: git clone https://github.com/ChyKusuma/SPHINXHybridKey.git
2. Install the necessary dependencies (List the dependencies or provide a link to the installation guide).
3. Explore the codebase to understand the project structure and components.
4. Run the project or make modifications as needed.

Contributing

We welcome contributions from the developer community to enhance the SPHINX blockchain project. If you are interested in contributing, please follow the guidelines below:

1. Fork the repository on GitHub.
2. Create a new branch for your feature or bug fix: git checkout -b feature/your-feature-name or git checkout -b bugfix/your-bug-fix.
3. Make your modifications and ensure the code remains clean and readable.
4. Write tests to cover the changes you've made, if applicable.
5. Commit your changes: git commit -m "Description of your changes".
6. Push the branch to your forked repository: git push origin your-branch-name.
7. Open a pull request against the main repository, describing your changes and the problem it solves.
8. Insert your information (i.e name, email) in the authors space.

License

Specify the license under which the project is distributed (MIT License).

Contact

If you have any questions, suggestions, or feedback regarding the SPHINX blockchain project, feel free to reach out to us at [email protected].