What Is Bridging? (A simple overview)

Blockchain technology has the potential to revolutionize the way that businesses and organizations operate, offering increased security, transparency, and efficiency. However, one of the challenges facing the widespread adoption of blockchain is the fact that different networks often operate in isolation, with limited ability to communicate and exchange information and assets.

Bridging in blockchain is a solution to this problem and is like a high-tech game of telephone, allowing two separate blockchain networks to communicate and exchange information and assets. Think of it as a "bridge" or "relay" that serves as a mediator between the two networks, connecting them in a seamless and secure way. The end goal of this connection is blockchain interoperability.

We love this overview from Whiteboard Crypto if you want a quick video about how bridging works.

Benefits of Bridging

A blockchain bridge serves as a gateway linking multiple separate blockchains, allowing for the transfer of data and assets between them. In terms of functionality, a cross-chain bridge converts a native asset from one blockchain into its corresponding asset on a different blockchain.

One of the primary benefits of bridging in blockchain is the ability to expand the reach and functionality of a particular blockchain. For example, an enterprise may want to use a permissioned blockchain for certain internal processes, but also want to connect to a public blockchain to take advantage of its greater security and transparency. By using a bridge, the enterprise can securely link its permissioned blockchain to the public blockchain, enabling it to access the benefits of both networks.

Bridging can also facilitate the exchange of assets between different blockchains. For example, a user on one blockchain may want to send a digital asset you're managing, such as a cryptocurrency, to a user on another blockchain. A bridge can facilitate this transfer by allowing the asset to be "wrapped" in a form that can be recognized and transferred between the two networks.

Types of Bridges

There are several types of blockchain bridges that serve different purposes and operate in different ways. Here are the six main types of blockchain bridges:

1. Cross-chain bridges: A cross-chain bridge is a form of decentralized application that allows the exchange of assets or information between two different blockchain networks that use different protocols and technologies. For example, a cross-chain bridge could allow the transfer of a token from the Ethereum network to the Bitcoin network.

2. Sidechain bridges: Sidechain bridges allow the transfer of assets or information between a main blockchain network and a sidechain. A sidechain is a separate blockchain that is pegged to the main blockchain and can be used to perform specific functions or experiments without affecting the main blockchain.

3. Federated bridges: Federated bridges are operated by a group of trusted parties, known as a federation, who are responsible for validating and facilitating the transfer of assets or information between two different blockchain networks.

4. Hashed timelock contracts (HTLCs): HTLCs are a type of smart contract that allows the transfer of assets or information between two parties in a trustless manner. The transfer is only completed if the recipient can provide a cryptographic proof that they have received the assets or information.

5. Programmable token bridges: Programmable token bridges combine token bridging with arbitrary data messaging capabilities, allowing for the transfer of not just tokens but any type of data between blockchains. This type of bridge can facilitate more complex cross-chain functionality, such as swapping, lending, staking, or depositing tokens in a smart contract on the destination chain.

6. Trust-minimized bridges: These are designed to provide the strongest trust-minimization guarantees, but may be less flexible and more computationally expensive as a result. These types of bridges are often used in use cases that require the highest level of security and trust.

Risks of Bridges

While bridging in blockchain can provide many benefits, it also carries certain risks and challenges. One key issue is the need to ensure the security and integrity of the bridge itself, as it serves as a critical point of communication between the two networks. If the bridge is compromised, it could potentially allow malicious actors to gain access to sensitive information or assets.

Another concern is finality. This is the guarantee that funds on the destination chain will be available once they've been committed on the source chain. Without finality, a reversed transaction on the source chain (like a block reorganization) could cause problems on the destination chain, like creating unbacked bridged tokens.

Final Thoughts

Blockchain bridging is a valuable tool for connecting different blockchain networks and facilitating the exchange of assets and information between them. Bridging to public chains is supported on Kaleido through products such as our NFT Platform.

That being said, there are also other ways that Kaleido can facilitate the process of transferring data between chains. One is our Public Ethereum Tether that allows you to pin state proofs from your Kaleido chain to Public Ethereum. What this means is that hashes, or proof of a transaction, are immutably added to the public blockchain but not the private, sensitive data. Try it today!