Back to Home
Security Documentation
Security Documentation

Learn More About Our Security

Complete user documentation on how our Polygon Card system works, with a focus on security and the critical importance of protecting your private key.

1.System Overview

Understanding the fundamentals of our Web3 virtual card system

What is a Web3 Virtual Card?

Our Web3 virtual card is a decentralized payment solution that combines the convenience of traditional credit cards with the security and transparency of blockchain technology. Unlike traditional cards, your virtual card is represented by a unique NFT (Non-Fungible Token) and is secured by cryptographic keys that only you possess.

Key Features

  • Decentralized: No central authority controls your card or funds
  • NFT Ownership: Each card is a unique NFT minted to your wallet
  • Private Key Access: Only you can access your card data using your private key
  • Transparent: All transactions are recorded on the blockchain
  • No KYC Required: Get started instantly without identity verification

2.How It Works

Step-by-step guide to getting and using your virtual card

1

Connect Your Wallet

Start by connecting your Web3 wallet (MetaMask, WalletConnect, or Coinbase Wallet). This wallet will be used to receive your card NFT and manage your funds. No personal information or KYC verification is required - your wallet address is your identity.

2

Configure Spending Limits

Set your spending limits to control how much you can spend per day, per month, and per transaction. These limits help protect your funds and give you control over your card usage. You can adjust these limits later if needed.

3

Claim Your Card

When you claim your card, two critical things happen:

  • A unique NFT is minted to your wallet, proving ownership of your card
  • A private key is generated and displayed to you - SAVE THIS IMMEDIATELY
4

Access Your Card Data

To view your card details, manage settings, or check your balance, you'll need to use your private key. This ensures that only you can access your card information, even if someone else has access to your wallet address or NFT.

3.Private Key: Your Digital Identity

Understanding the most critical aspect of your card security

What is a Private Key?

A private key is a cryptographic string of characters (64 hexadecimal characters) that serves as your unique digital signature. Think of it as the master password to your card - it's the only way to decrypt and access your card's sensitive information, including:

  • Card number and CVV
  • Transaction history
  • Card settings and limits
  • Balance information

How to Store Your Private Key Safely

Recommended Methods

  • Write it down on paper and store in a safe or safety deposit box
  • Use a hardware wallet or secure password manager
  • Create multiple secure backups in different physical locations
  • Encrypt it and store the encrypted version separately

Never Do This

  • Store it in a screenshot or photo on your phone
  • Save it in an unencrypted text file or email
  • Share it with anyone, even "support" staff
  • Store it in cloud storage without encryption

Why We Don't Store Your Private Key

For your security, we use a zero-knowledge architecture. This means:

  • We never see or store your private key on our servers
  • Your card data is encrypted and can only be decrypted with your private key
  • Even if our systems are compromised, your data remains secure
  • You have complete control and ownership of your information

4.Unique Card NFT

Your card as a Non-Fungible Token on the blockchain

What is the Card NFT?

When you claim your virtual card, a unique NFT (Non-Fungible Token) is automatically minted to your connected wallet. This NFT serves as proof of ownership and represents your card on the blockchain. Each card has a unique Token ID that distinguishes it from all other cards.

What the NFT Proves

Ownership

The wallet that holds the NFT owns the card

Authenticity

The NFT is verifiable on the blockchain

Uniqueness

Each card NFT is one-of-a-kind

Transferability

You can transfer the NFT to another wallet (which transfers card ownership)

5.Security Best Practices

Essential security measures to protect your card and funds

Protect Your Private Key

  • •Store it in multiple secure locations
  • •Never share it with anyone
  • •Use hardware wallets for additional security
  • •Verify backups regularly

Protect Your Wallet

  • •Use strong wallet passwords
  • •Enable two-factor authentication where possible
  • •Keep your wallet software updated
  • •Be cautious of phishing attempts

Monitor Your Card

  • •Regularly check your transaction history
  • •Set appropriate spending limits
  • •Review card activity frequently
  • •Report suspicious activity immediately

General Security

  • •Use secure networks when accessing your card
  • •Keep your devices updated
  • •Be wary of suspicious links or emails
  • •Verify website URLs before entering information

6.Card Management

How to manage and use your virtual card

Accessing Your Card

To access your card information, you'll need to:

  1. Connect the wallet that holds your card NFT
  2. Enter your private key to decrypt and view card data
  3. View your card number, CVV, balance, and transaction history

Updating Spending Limits

You can update your spending limits at any time by accessing your card with your private key. Changes take effect immediately and help you maintain control over your spending.

Adding Funds

You can add funds to your card by transferring USDC (or other supported tokens) to your card's address. The funds will be available immediately once the transaction is confirmed on the blockchain.

Using Your Card

Your virtual card works like a traditional Mastercard. You can:

  • Add it to Apple Pay or Google Pay
  • Use it for online purchases
  • Make in-store purchases with contactless payment
  • Withdraw cash from ATMs (where supported)

7.Frequently Asked Questions

Q: What happens if I lose my private key?

A: Unfortunately, if you lose your private key, you will permanently lose access to your card data. We cannot recover it because we never store it. You would need to create a new card. This is why it's critical to store your private key securely in multiple locations.

Q: Can I recover my private key if I forget it?

A: No. Private keys cannot be recovered. This is a fundamental security feature of blockchain technology. If you lose your private key, there is no way to recover it. Always keep secure backups.

Q: What if someone steals my NFT?

A: If someone gains access to your wallet and transfers your NFT, they would own the card, but they still cannot access the card data without your private key. However, you should immediately report the theft and consider creating a new card if your wallet is compromised.

Q: Can I transfer my card to another wallet?

A: Yes, you can transfer the NFT to another wallet, which transfers card ownership. However, the new owner will still need your private key to access the card data. If you're transferring ownership, you should also securely transfer the private key.

Q: Is my card data stored on the blockchain?

A: No. Only the NFT ownership and transaction records are stored on the blockchain. Your card number, CVV, and other sensitive data are encrypted and stored off-chain. Only your private key can decrypt this information.

Q: What tokens can I use with my card?

A: Currently, cards are funded with USDC (USD Coin) on the Polygon network. You can add USDC to your card at any time. Support for additional tokens may be added in the future.

Q: Are there any fees?

A: Card creation is free. Standard blockchain transaction fees apply when adding funds or making transactions. There are no monthly fees or hidden charges.