Since the release of the Bitcoin whitepaper in 2008, there has been a lot of development in the industry, leading to widespread adoption. 

The focus of 2021 was on Layer 1s, which has led many to believe that the future of crypto will be multi-chain rather than one winner-takes-all blockchain. However, with the increase in the number and size of different blockchain ecosystems, there is a need for key infrastructure to connect them. This is where blockchain bridges come into play.

Web3 has evolved into a system of Layer 1 blockchains and Layer 2 scaling solutions, each with distinctive capabilities and trade-offs. As the number of blockchain protocols increases, the demand to move assets across chains consequently increases. One way to meet this demand is through bridges. 

What are bridges? 

Since each network has its own set of rules, governance mechanisms, native assets, and data that are incompatible with other blockchains, bridges are necessary for interoperability.

Just like a bridge in the physical world, blockchain bridges connect two networks—in this case, two blockchain ecosystems. Bridges enable communication between blockchains and allow the transfer of information and assets by using each chain's smart contract capabilities.

Wrapped tokens and the bridging process

A wrapped token is a cryptocurrency token that represents another cryptocurrency from a different blockchain or token standard. This token has the same value as the original cryptocurrency. 

Unlike the original cryptocurrency, the wrapped token can be used on non-native blockchains and can later be exchanged for the original cryptocurrency.

When a bridge is created between two blockchains, assets on the original blockchain are locked in a smart contract. At the same time, an equivalent token is minted on the target blockchain. To return to the original blockchain or bridge to another blockchain, the created token must first be burned to prevent a "double spend" effect.

What is Qtum doing?

Our goal in 2024 is to deploy the infrastructure that’s needed for developers to build or integrate Web3 utilities. We’re implementing a bridge that will allow users to wrap and transfer tokens from Ethereum to Qtum and back. We’re also providing a “MetaMask Snap” that will allow users to store and interface with Web3 utilities on Qtum.

The emphasis right now is on a secure method of moving Ethereum ERC-20 assets back and forth between Qtum and Circle’s USDC stablecoin.

We’re deploying the USDC “Bridged Stablecoin Standard” set of contracts on Qtum and Ethereum, which will bring wrapped USDC to Qtum. There will also be the option to bridge any wrapped Ethereum asset to Qtum and back.

The DeFi opportunities that come with a stablecoin are too obvious to mention. What is worth mentioning is the fact that there’s no Qtum/stablecoin liquidity pool on any chain, which gives us the first-mover advantage.

NFTs have been possible on Qtum for some time, but there hasn’t been much traction without a stablecoin. BRC-20 tokens will also be available on Qtum, as the network supports both the UTXO and Accounts model natively. 

Because Qtum is capable of deploying token standards available to UTXO chains, there may be a possibility for Ordinal inscriptions to co-exist in a DeFi environment on a hybrid UTXO/EVM chain like Qtum, which isn’t something the non-UTXO smart contract chains can do without token wrapping or somehow interfacing with a smart contract model. If this method went outside of inscribing satoshis on a UTXO model, it would be BRC-20 in name only.

Concept Art of Qtum Bridge Interface

Latest updates:

• A bridge has been developed to connect the "Circle Bridged USDC" contracts deployed on Qtum testnet and Ethereum Sepolia. 

• The bridge is being audited by Certik. 

• A MetaMask Snap implementation has been developed for the bridge as a Chrome extension.

Development Test Version of “Metamask Snap” being tested with the Qtum Bridge.

Listed below is a demo flow of how users will interact with the testnet bridge:

Go to https://wallet.bridge.qtum.net and create a new snap wallet or import existing private key.

Transfer USDC from Sepolia to Qtum testnet:

1. Open bridge.qtum.net and choose Sepolia as “Chain From.”

2. Connect Metamask

3. Enter the amount and destination address from the snap.

4. Click Transfer.

5. Wait until the transaction is confirmed.

6. You will see a button to connect snap. Connect snap.

7. Click the redeem button to send the transaction via snap.

8. You will see the updated balance on https://wallet.bridge.qtum.net.

Transfer USDC from Qtum testnet to Sepolia:

1. Disconnect the current provider and choose Qtum testnet as “Chain From.”

2. Connect snap.

3. Enter the amount and address on Sepolia.

4. Click Transfer to “send transaction” via snap.

5. Wait until the transaction is confirmed.

6. Click the button to disconnect snap and connect MetaMask.

7. Click the button to redeem USDC.

Note that this is a demo version, and bugs have been found. Here are some known issues:

• You have to disconnect Metamask/Snap and connect again when switching networks.

In some cases, wallet.bridge.qtum.net may evict storage. In this case, just reimport your private key.

Join the Qtum Community

If you are yet to become a part of our community, we invite you to join us and stay updated on the latest developments, participate in discussions, and contribute to the growth of the Qtum ecosystem.

• Qtum Discord

• Qtum Twitter

• Qtum Facebook