CryptoWave

Make crypto payments with NFC and Vouchers for larger adoption along with Gasless features.

Overview

CryptoWave enables seamless crypto payments through NFC and Vouchers. The project focuses on enhancing adoption by introducing gasless transactions and innovative features.

Features

1. Bonds (Vouchers)

   • Create vouchers locking tokens in contracts.
   • Redeem vouchers using a SecretKey.
   • Redeem vouchers gasless

2. NFC Pay

   • Spend and accept crypto using NFC.
   • No KYC required.
   • Build your own NFC payment devices.
   • Spending limits onchain

Integrations

1. Biconomy

   • Gasless transactions with ERC2771 relayed during voucher redemption.
   • Users never pay fees.
   • Transaction with Biconomy Relay

2. Chainlink CCIP

   • CrossChain Messaging from supported chains (Sepolia) to the base chain.
   • CCIP Message & DataFeed Integration
   • Transaction Explorer

3. LayerZero

   • CrossChain Messaging for other EVM chains (Scroll, Mantle, Zkevm, Polygon, Celo, Linea).
   • Deposits are processed via Layerzero cross-chain messaging from Mumbai to Base Testnet.
   • LayerZero Transaction Explorer

4. NFT.Storage

   • Create IPFS hash to transfer signed messages between NFC devices.
   • Accommodate larger data in bytes data size.
   • IPFS Hash for NFC Data
   • Corresponding JSON with spender address and messageHash.

5. Chainlink Datafeed

   • Determine USD value of user-deposited tokens to issue $ value on NFC payment chain. If datafeed is missing use default value

How Bonds Work

Bonds are created seamlessly across various blockchain networks, offering the flexibility to be redeemed on the same chain where they were initiated. The process involves the following key steps:

1. Token Deposit:

   • Users deposit allowed tokens to create a bond.

2. Supplying Unique Key - "secretKey":

   • Users supply a unique key called "secretKey" during the bond creation process.

3. Hash Generation:

   • A Keccak256 hash is generated from the provided secretKey.

4. On-Chain Storage:

   • The generated hash is securely stored on the blockchain as part of the bond creation transaction.

5. Redemption Process:

   • When redeeming a bond, users provide the secretKey.
   • The system verifies if the hash of the provided secretKey matches the stored hash on the blockchain.

6. Gasless Transaction with Biconomy SDK:

   • The redemption transaction is executed seamlessly and gaslessly using the Biconomy SDK.
   • Users receive back their initial tokens upon successful redemption.

This process ensures a secure and gas-efficient bond creation and redemption experience across different blockchain networks.

How NFC Payments Work

NFC (Near Field Communication) payments on the base chain serve as the payment chain, holding a USD value in user balances on the contract. The process involves several key steps:

1. Balance Loading:

   • Users can add money to their balance by supplying approved assets on multiple chains.
   • Chainlink data feed is utilized to determine the USD value of the user's assets.

2. Cross-Chain Messaging:

   • A cross-chain message is sent to the base chain (payment chain) to update the user's balance.

3. Spend Limit Feature:

   • Users can set a custom spend limit, ensuring controlled spending within their wallet balance.
   • The spend limit is less than the loaded balance and is suitable for tap payments.

4. Unique Hash Generation:

   • Upon setting the spend limit, users receive a unique hash associated with their NFC card.

5. NFC Card Tap for Payment:

   • Users tap their NFC card to initiate payments up to their set spend limit.
   • The irreversible nature of blockchain transactions is managed through this secure process.

6. Transaction Verification and Centralized Relayer:

   • An API is maintained to verify spending limits on-chain.
   • The transaction is processed using a centralized relayer for swift confirmation.
   • The limitUsed variable is updated to ensure users never exceed their set spend limit.

This comprehensive approach ensures a secure, user-controlled NFC payment experience, where users can confidently tap their cards for convenient and controlled transactions.

Chain Deployments (Bonds)

• Goerli testnet
• Mumbai testnet
• ZkEvm testnet
• Celo testnet
• Mantle testnet

Chain Deployments (NFC Wallet Deposits)

• Sepolia
• Mumbai Polygon
• Mantle
• Celo
• ZkEvm
• Arbitrum
• Scroll
• Linea
• Base (This acts as Payment chain)

Deployment Addresses Bonds

Goerli Testnet

Contract Address	DAI	USDC	LINK
0x5013d127469B5088E4B4576b51C7D6303ADa9D20	0x8E89aB6F92B0Cdf99be9FFcee448df8198F8EaE7	0x67BFa3C931d3e6C73BFBEA2C87257B4C36839875	0xb598418856fcF1b865D2fc8d82e22Dfb9a8fCE5a

Mumbai Testnet

Contract Address	DAI	USDC	LINK
0x5013d127469B5088E4B4576b51C7D6303ADa9D20	0x67BFa3C931d3e6C73BFBEA2C87257B4C36839875	0xb598418856fcF1b865D2fc8d82e22Dfb9a8fCE5a	0x8E89aB6F92B0Cdf99be9FFcee448df8198F8EaE7

Zkevm Testnet

Contract Address	DAI	USDC	LINK
0x5013d127469B5088E4B4576b51C7D6303ADa9D20	0x67BFa3C931d3e6C73BFBEA2C87257B4C36839875	0xb598418856fcF1b865D2fc8d82e22Dfb9a8fCE5a	0x8E89aB6F92B0Cdf99be9FFcee448df8198F8EaE7

Celo Testnet

Contract Address	DAI	USDC	LINK
0x5013d127469B5088E4B4576b51C7D6303ADa9D20	0x8E89aB6F92B0Cdf99be9FFcee448df8198F8EaE7	0xb598418856fcF1b865D2fc8d82e22Dfb9a8fCE5a	0x67BFa3C931d3e6C73BFBEA2C87257B4C36839875

Mantle Testnet

Contract Address	DAI	USDC	LINK
0x5013d127469B5088E4B4576b51C7D6303ADa9D20	0x67BFa3C931d3e6C73BFBEA2C87257B4C36839875	0xb598418856fcF1b865D2fc8d82e22Dfb9a8fCE5a	0x8E89aB6F92B0Cdf99be9FFcee448df8198F8EaE7

NFC Deposits Addresses:

Sepolia Testnet:

NFC Deposit Address	LINK	DAI	USDC
0xb598418856fcF1b865D2fc8d82e22Dfb9a8fCE5a	0xd2F474D09B552C0C2cACC330d29440E622FE5917	0x90e413963e68b90153F8370924Bd0FB6d504B778	0xCE60598B9320D47e78f8B60eCF7F6a9e5986a161

Mumbai Testnet:

NFC Deposit Address	LINK	DAI	USDC
0x90e413963e68b90153F8370924Bd0FB6d504B778	0xCE60598B9320D47e78f8B60eCF7F6a9e5986a161	0xe12A2d74E17659Cca2c111257992BA68eA42Ba77	0x80c4F3957E75686593A91e146503f2aa9A5FDe23

Mantle Testnet:

NFC Deposit Address	LINK	DAI	USDC
0xD3ae32608fd2a86CF5a4652Ab4E6A08f4509f685	0x90e413963e68b90153F8370924Bd0FB6d504B778	0xCE60598B9320D47e78f8B60eCF7F6a9e5986a161	0x80c4F3957E75686593A91e146503f2aa9A5FDe23

Celo Testnet:

NFC Deposit Address	LINK	DAI	USDC
0x80c4F3957E75686593A91e146503f2aa9A5FDe23	0x90e413963e68b90153F8370924Bd0FB6d504B778	0xCE60598B9320D47e78f8B60eCF7F6a9e5986a161	0xe12A2d74E17659Cca2c111257992BA68eA42Ba77

Zkevm Testnet:

NFC Deposit Address	LINK	DAI	USDC
0x90e413963e68b90153F8370924Bd0FB6d504B778	0xCE60598B9320D47e78f8B60eCF7F6a9e5986a161	0xe12A2d74E17659Cca2c111257992BA68eA42Ba77	0x80c4F3957E75686593A91e146503f2aa9A5FDe23

Arbitrum Testnet:

NFC Deposit Address	LINK	DAI	USDC
0x5013d127469B5088E4B4576b51C7D6303ADa9D20	0x8E89aB6F92B0Cdf99be9FFcee448df8198F8EaE7	0x67BFa3C931d3e6C73BFBEA2C87257B4C36839875	0xb598418856fcF1b865D2fc8d82e22Dfb9a8fCE5a

Scroll Testnet:

NFC Deposit Address	LINK	DAI	USDC
0x90e413963e68b90153F8370924Bd0FB6d504B778	0x8E89aB6F92B0Cdf99be9FFcee448df8198F8EaE7	0x67BFa3C931d3e6C73BFBEA2C87257B4C36839875	0xd2F474D09B552C0C2cACC330d29440E622FE5917

Linea Testnet:

NFC Deposit Address	LINK	DAI	USDC
0x8E89aB6F92B0Cdf99be9FFcee448df8198F8EaE7	0x67BFa3C931d3e6C73BFBEA2C87257B4C36839875	0xb598418856fcF1b865D2fc8d82e22Dfb9a8fCE5a	0xd2F474D09B552C0C2cACC330d29440E622FE5917

NFC Payment Base

NFC Wallet: 0x5013d127469B5088E4B4576b51C7D6303ADa9D20

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