What is a blockchain bridge?

· 5 min read
What is a blockchain bridge?
A blockchain bridge facilitates interoperability between two independent blockchain networks. 

A blockchain bridge facilitates interoperability between two independent blockchain networks. To achieve interoperability within the blockchain ecosystem, blockchain bridges are essential. Simply put, a blockchain bridge lets you participate in activities on a blockchain network, even if the crypto you hold is on another Blockchain.

Over recent times, the crypto community around the world has come to realise the need for blockchain bridges. Unfortunately, as the number of blockchain networks continues to grow, they remain primarily isolated, like islands with their own communities or economies that can’t transact with each other. The siloed nature of these blockchain networks is a detriment to the very purpose for which these blockchains were created in the first place.

Not only does the lack of interaction between blockchain networks limit decentralisation, but it also restricts the progress of crypto trading activities. Typically, protocols designed for one network only work within that network, limiting their use and lowering their adoption among the masses.


Understanding the meaning of Blockchain is essential before one even attempts to understand the term Blockchain Bridge. Some of the most common blockchain networks include Bitcoin, Ethereum, and Binance Smart Chain. These platforms use varying consensus methods, coding languages, and system regulations.

A blockchain bridge is a protocol that links two isolated blockchains that are economically and technologically distinct to allow communication between them. These protocols serve as a virtual bridge connecting different blockchain ecosystems, like a bridge connecting isolated islands.

As a result, blockchain bridges enable interoperability, allowing communication between digital assets and data maintained on different blockchains. The foundation of the internet is interoperability: To speak with one another, machines worldwide use a standard set of open protocols. Blockchain bridges are necessary for the blockchain ecosystem, where numerous unique protocols exist, to allow for similar ease of sharing data and currency.

Why are blockchain bridges necessary?

One of the most critical constraints on the growth and development of the blockchain industry has been the inability of various blockchains to cooperate and interact with one another. Each Blockchain has its own protocols, smart contracts, coins, and rules. Blockchain bridges assist in bridging these divisions and connecting the disparate crypto ecosystems. Tokens and data can easily be exchanged between blockchains connected to one another.

Blockchain bridges offer further advantages besides facilitating cross-chain transactions. Thanks to them, users can access new protocols on other chains, enabling developers from other blockchain communities to work together. In other words, if the blockchain industry is to become interoperable in the future, blockchain bridges will be essential.

How do blockchain bridges function?

The token transfer is the most typical application for a blockchain bridge. For instance, you might want to send your bitcoin (BTC) to the Ethereum network. One method is to sell your BTC and buy ether (ETH). However, such a transaction would be subject to price volatility and transaction costs.

Alternatively, employing a blockchain bridge can accomplish this goal without selling your cryptocurrency. Instead, the smart contract supporting the blockchain bridge will lock your Bitcoin and create an equivalent amount of Wrapped Bitcoin (WBTC), an ERC20 token compatible with the Ethereum network, when you bridge 1 Bitcoin to an Ethereum wallet. A wrapped token is a tokenised or converted version of a cryptocurrency.

Each wrapped token holds a value that is the same as the original asset it represents, making it interchangeable. As a result, you can easily use a non-native coin on a blockchain for borrowing, lending, and trading. In addition, the tokens are wrapped into a digital vault that allows a non-native token to be operated on the blockchain.

Your desired quantity of Bitcoin is secured in a smart contract, and the corresponding tokens on the destination blockchain network are created or issued. A wrapped token is a cryptocurrency that has been tokenised. It is usually redeemable (unwrapped) at any time and is pegged to the value of the asset it stands for.

This method involves a few steps from the user's perspective. For instance, to use the Binance Bridge, you must first choose the chain from which to bridge and enter the amount. The cryptocurrency will subsequently be deposited to a Binance Bridge-generated address. Finally, Binance Bridge will pay you an equivalent amount of wrapped fiat after the crypto has been transmitted to the address throughout the time range.

Pros and Cons of Blockchain Bridges


The capacity to increase interoperability is the key advantage of blockchain bridges.

They make it possible to transfer tokens, assets, and data between different sidechains, layer 1 and layer 2 protocols, and other blockchains. Users of bitcoin can, for instance, explore the decentralised applications (dapps) and DeFi services of the Ethereum ecosystem using WBTC. The blockchain industry's future success depends on an interoperable sector.

Blockchain bridges also help to increase scalability. Some blockchain bridges can process numerous transactions at once, increasing productivity. For instance, the decentralised two-way bridge known as the Ethereum-Polygon Bridge serves as a scaling option for the Ethereum network. Users can gain from quicker transactions and fewer transaction expenses as a result.


Blockchain bridges do have some restrictions, though. Attackers have taken advantage of several blockchain bridges' smart contracts' weaknesses. Malicious actors have taken enormous amounts of cryptocurrency from cross-chain bridges.

Users of custody bridges may be subject to custody hazards. It is theoretically possible for the central organisation to hide a custodial bridge to siphon off user money. When employing custodial bridges, choose well-known companies with a proven track record.

Transaction rate bottlenecks are an additional potential technical constraint. Large-scale blockchain interoperability may be hampered by a single chain's bottleneck in throughput capacity.

A bridge can help a busy network become less congested. Still, shifting assets to a different chain won't address the problem of scalability because consumers won't always have access to the same collection of dapps and services. The Polygon Bridge, for instance, does not support all Ethereum dapps, which reduces the Polygon Bridge's scaling effectiveness.

Finally, blockchain bridges may expose the underlying protocols to dangers due to the trust gap. Furthermore, since blockchain bridges link many blockchains together, the security of the connected systems is only as strong as its weakest link.

What's the future of blockchain bridges?

The internet's great interoperability is one of the reasons it is a revolutionary system. Enhancing interoperability and wide-scale adoption of the blockchain sector requires blockchain bridges. They have made it possible for consumers to exchange assets between numerous blockchain protocols, which has enabled some crucial improvements. As a result, the number of bridges, users, and overall transaction volume for blockchain bridges has increased dramatically.

As the internet transitions to Web3, the demand for blockchain bridges will probably continue to increase. Future advancements might give users and developers more scalability and efficiency. In addition, there might be creative ways to deal with the security issues of bridges. Building an open, decentralised, and interoperable blockchain space requires using blockchain bridges.


Constant innovation is what propels the blockchain industry's growth. A plethora of alternative layer 1 and layer 2 blockchains are followed by pioneer protocols like the Bitcoin and Ethereum networks. As a result, the number of cryptocurrency tokens and coins has multiplied rapidly.

They require blockchain bridges to be interconnected since they use different regulations and technologies. An ecosystem of bridges connecting a blockchain is more coherent and interoperable, providing prospects for increased scalability and efficiency. The need for a more secure and resilient bridge design is ongoing due to the frequent attacks on cross-chain bridges.