The Project

Overview

This project consists of two main products designed for users interacting with the Solana blockchain:

1. Wallet Creation: Users can create their own cryptocurrency wallet using Web3Auth, currently supporting only the Solana blockchain.
2. Link-based Crypto Sharing: Users can create a secure link to share cryptocurrency with others, leveraging cryptographic techniques to ensure the safety and integrity of the transaction.

Product 1: Wallet Creation

Introduction

This feature allows users to create a Solana wallet easily using Web3Auth. Web3Auth simplifies the onboarding process by abstracting away the complexity of key management, enabling users to create and manage their wallets without directly dealing with private keys. Importantly, this project is non-custodial, meaning private keys are never stored by the platform, ensuring that users have full control over their funds.

How Web3Auth Works

Web3Auth is a decentralized authentication infrastructure that provides a seamless user experience by integrating with OAuth providers (like Google, Facebook, etc.) and social logins.

Internal Key Management and the Torus Network

Web3Auth uses the Torus Network for decentralized key management. Here’s how it works:

1. Private Key Sharding:

   • When a private key is generated, it is broken into multiple shards.
   • These shards are distributed across different nodes in the Torus Network.

2. Decentralized Storage:

   • Shards are stored on a decentralized network of nodes, ensuring no single entity has control over the full key.
   • This decentralization reduces the risk of a single point of failure.

3. Threshold Decryption:

   • The private key can be reconstructed using a threshold number of shards, even if some nodes are compromised or offline.
   • This method ensures the security and availability of the private key.

4. Social Login Recovery:

   • If a user loses access to their device, they can recover their wallet by logging in via the same social OAuth provider.
   • The Torus Network reassembles the private key using the required number of shards upon successful login.

The Torus Network

The Torus Network is the backbone of Web3Auth’s decentralized key management:

• Decentralized: Multiple independent nodes manage the shards, preventing central control.
• Secure: Threshold cryptography ensures the private key remains secure, even if some nodes are compromised.
• Scalable: The network can handle a large number of users, ensuring fast and efficient key reconstruction and transaction signing.

Key Benefits

• User-Friendly: Simplifies wallet creation for non-technical users.
• Secure: Distributes key management across multiple nodes, reducing the risk of key compromise.
• Non-Custodial: Users have full control over their private keys, as they are never stored on the platform.
• Scalable: Supports a large number of users with minimal configuration and setup.

Product 2: Link-Based Crypto Sharing

Introduction

This feature enables users to generate a link that contains a cryptographic keypair, allowing them to share cryptocurrency with others securely. The recipient of the link can access the funds associated with the keypair.

Core Concepts

• Coinwala Cryptography: The system uses cryptographic methods to encode a keypair within a URL, allowing the secure transfer of funds.
• Key Derivation Function (KDF): A Key Derivation Function is used to generate a cryptographic keypair from a password and a salt.
• Sodium Library: The libsodium library is used for various cryptographic operations.

Code Breakdown

Below is an explanation of the main components used in the implementation:

Constants and Defaults

• DEFAULT_HYPERLINK_KEYLENGTH: The length of the cryptographic key used to generate the wallet (32 bytes, equivalent to 256 bits).
• DEFAULT_ORIGIN: The default URL origin for the generated link.
• HYPERLINK_ORIGIN: A configurable origin for the generated link, allowing for environment-specific URLs.
• HYPERLINK_PATH: The path appended to the origin to create the final URL.
• VERSION_DELIMITER & CURRENT_VERSION: Define the versioning scheme used in the URL, enabling backward compatibility and validation.

Helper Functions

• getSodium(): Loads the libsodium library asynchronously, ensuring that cryptographic operations can proceed once the library is ready.
• kdf(): The Key Derivation Function takes a password and salt as inputs and returns a cryptographic key of the specified length.
• randBuf(): Generates a secure random buffer of the specified length using the libsodium library.
• pwToKeypair(): Converts a password and salt into a cryptographic keypair using the key derivation function.

CoinWala Class

The CoinWala class is the core of the link-based crypto sharing functionality:

• Properties:

  • url: The generated URL containing the cryptographic information.
  • keypair: The Solana keypair derived from the password and salt.
  • salt: The salt used in the key derivation process.

• Methods:

  • create(): Generates a new CoinWala instance with a random password and salt, derives the corresponding keypair, and encodes the information into a URL.
  • fromUrl(url: URL): Parses an existing URL to extract the password and salt, regenerates the keypair, and returns a CoinWala instance.
  • fromLink(link: string): Convenience method to create a CoinWala instance from a string link.

Example Usage

1. Creating a New Link:

   const newLink = await CoinWala.create();