Relay: A Decentralized Encrypted Messaging dApp

Introduction

Welcome to Relay, a decentralized messaging dApp built on the Solana blockchain. In the era of Web3, our goal is to provide a secure and censorship-resistant platform for communication. With Relay, you can send encrypted messages without worrying about central authorities intercepting, leaking, or blocking your communication.

Features

• End-to-End Encryption: Messages are encrypted using your private key and the recipient's public key. This ensures that only the intended recipient can decrypt and read the message.
• Decentralization: Hosted on the Solana blockchain, Relay eliminates the risk of central control or shutdown.
• Privacy and Security: No central authority can access or tamper with your messages.

Use Cases

Anonymous Communication: Relay allows for secure and anonymous communication, protecting user identity.

Resistant to Censorship: Messages cannot be blocked or censored by any central authority.

Data Integrity: Ensures that the message data remains unchanged and secure.

Current Application Web design

Landing Page

Create Your Own Key Pairs

Clicking on "Create Your own Key Pairs" gives your own Public and Private keys.

Each user must generate a keypair (public key + private key) using TweetNaCl. After generating their keys, both users exchange their public keys with each other.

Only public keys are shared. Private keys must remain secret.

Relay App

Click on relay to go to Chat app

Connect Wallet

Currently shows all messages on teh Smart contract but in future it can show only your messages. All encrypted messages will have a Decrypt button to decrypt.

Send Secret Message

Address - can be anything

Message - Secret message to encrypt

Recipient Public Key - Other users public key with whom you want to message secretly.

Your private key -

Your public Key

Example -

After submitting you see on the Chat relay;

Check Txn on Solana Blockchain Explorer

https://explorer.solana.com/address/5ZeMSd6ot2FPBBAt1s4hF3ffKAjNvp1LvFNT62FPqQCi?cluster=devnet

Recipient Viewing the message

Decrypt

Application Detail

Technology Stack

• Solana Blockchain: Ensures decentralized hosting and high transaction throughput.
• TweetNaCl: Utilized for encrypting messages. It provides cryptographic functions to ensure data security.
• Web3.js: Used to connect to the Solana network and interact with smart contracts.
• Phantom Wallet: Integrated for managing user wallets and signing transactions.
• Anchor Framework: Simplifies Solana program development and deployment.

Encryption Process

Relay uses TweetNaCl for encryption:

• Encryption: The sender's private key and the recipient's public key encrypt the message.
• Decryption: The recipient's private key and the sender's public key decrypt the message. This ensures that only the intended recipient can read the message, providing robust security.

UI Architecture

Relay's front-end is built with React, leveraging various libraries for a seamless user experience:

• React Query: Manages data fetching and caching.
• React Hot Toast: Provides user notifications.
• Solana Wallet Adapter: Integrates Phantom Wallet for user authentication.
• Tailwind CSS: For styling components.

Example Imports

javascriptCopy codeimport { useWallet } from '@solana/wallet-adapter-react';
import { LAMPORTS_PER_SOL, PublicKey } from '@solana/web3.js';
import { useQueryClient } from '@tanstack/react-query';
import { useConnection } from '@solana/wallet-adapter-react';
import { TOKEN_2022_PROGRAM_ID } from '@solana/spl-token';
import { Connection, SystemProgram, VersionedTransaction } from '@solana/web3.js';
import { useMutation, useQuery } from '@tanstack/react-query';
import toast from 'react-hot-toast';
import { useTransactionToast } from '../ui/ui-layout';

Anchor and Smart Contracts

Relay uses the Anchor framework for Solana smart contract development. Here's a brief overview of our lib.rs:

rustCopy codeuse anchor_lang::prelude::*;

#[program]
pub mod relay {
    use super::*;
    pub fn send_message(ctx: Context<SendMessage>, message: String) -> ProgramResult {
        let message_account = &mut ctx.accounts.message_account;
        message_account.message = message;
        Ok(())
    }
}

#[account]
pub struct MessageAccount {
    pub message: String,
}

Deployment

Relay is hosted on Vercel and accessible at: Relay dApp

Conclusion

Relay provides a secure, decentralized platform for encrypted messaging, ensuring privacy and freedom from central control. Join us in embracing the Web3 revolution and enjoy secure communication with Relay.