Brief content
A blockchain bridge is a protocol that connects two blockchains to ensure interaction between them. If you own bitcoins but want to participate in DeFi activity on the Ethereum network, Blockchain Bridge will allow you to do so without selling your bitcoins. Blockchain bridges are fundamental to achieving interoperability in the blockchain space.
Introduction
To understand what a blockchain bridge is, you need to first understand what a blockchain is. Bitcoin, Ethereum and BNB Smart Chain are among the main blockchain ecosystems based on different consensus protocols, programming languages and system rules.
A blockchain bridge is a protocol that connects two economically and technologically separate blockchains to ensure interaction between them. These protocols function as a physical bridge connecting one island to another, with the islands being separate blockchain ecosystems.
Thus, blockchain bridges provide what is called interoperability. This means that digital assets and data hosted on one blockchain can interact with another. Interoperability is a cornerstone of the Internet: devices around the world use the same set of open protocols to communicate with each other. In the blockchain space where there are many different protocols, blockchain bridges are necessary to provide a similar ease of exchange of data and value.
Why do we need blockchain bridges?
During the development and expansion of the blockchain space, one of the most significant limitations is the inability of different blockchains to work together. Each blockchain has its own rules, tokens, protocols and smart contracts. Blockchain bridges help change these structures and connect isolated cryptoecosystems. An interconnected network of blockchains can ensure a seamless exchange of tokens and data between them.
In addition to the possibility of cross-chain transfers, blockchain bridges provide other benefits. They allow users to access new protocols on other chains. They also allow developers from different blockchain communities to collaborate. In other words, blockchain bridges are the most important component of the interoperable future of the blockchain industry.
How do blockchain bridges work?
The most common use of a blockchain bridge is token transfer. For example, you want to transfer your Bitcoin (BTC) to the Ethereum network. One way is to sell your BTC and then buy ether (ETH). However, this transaction will require a transaction fee and will be subject to price volatility.
But you can achieve this goal by using a blockchain bridge without selling your cryptocurrency. When you convert 1 BTC through the bridge to an Ethereum wallet, the bridge blockchain contract will lock your BTC and create an equivalent amount of Wrapped BTC (WBTC), which is an ERC20 token compatible with the Ethereum network. The amount of BTC you want to transfer is fixed in a smart contract, and equivalent tokens are issued or minted on the destination blockchain network. A wrapped token is a tokenized version of another cryptocurrency. It is tied to the value of the asset it represents and can usually be exchanged for it (deployed) at any moment.
From the user's perspective, this process takes several steps. For example, to use Binance Bridge, first select the chain you want to convert from and specify the amount. Then deposit the cryptocurrency to the address generated via Binance Bridge. Once the cryptocurrency is sent to the address within the time window, Binance Bridge will send you an equivalent number of wrapped tokens on another blockchain. If you wish to convert your funds back, you simply follow the reverse process.
What types of blockchain bridges are there?
Blockchain bridges can be categorized according to their functions, mechanisms and levels of centralization.
Custodial and non-custodial bridges
Blockchain bridges can be divided into two types: custodial (centralized) and non-custodial (decentralized).
Custodial bridges require users to trust a central organization for the proper and secure operation of the system. Users should do thorough research to ensure that this organization is trustworthy.
Non-custodial bridges operate in a decentralized manner, relying on smart contracts to manage the locking and minting processes of cryptocurrency, eliminating the need to trust the bridge operator. In this case, the security of the system is only as reliable as its underlying code.
Types of blockchain bridges by function
Another classification is how the blockchain bridge functions. Some examples are wrapped asset bridges and sidechain bridges.
Wrapped asset bridges provide crypto-compatibility, such as bringing Bitcoin to the Ethereum network by converting BTC to Wrapped BTC (WBTC), an ERC20 token compatible with the Ethereum network. Side-chain bridges connect the main blockchain with its child side-chain, ensuring compatibility between them. They are necessary because the main blockchain and the sidechain may have different consensus mechanisms. One example is the xDai Bridge, which connects the Ethereum mainnet to the Gnosis Chain (formerly the xDai blockchain), a stable payment sidechain based on Ethereum. xDai is secured by a different set of validators than those supported by the Ethereum network. xDai Bridge makes it easy to transfer value between two chains.
Types of blockchain bridges by mechanisms
There are one-way bridges and two-way bridges. With one-way bridges, users can only convert assets to one target blockchain, but not back to its native blockchain. Two-way bridges allow you to convert assets in both directions.
Advantages of blockchain bridges
The most important benefit of blockchain bridges is the ability to improve interoperability.
They allow the exchange of tokens, assets and data between different blockchains, both between layer 1 and 2 protocols, and between different sidechains. For example, WBTC allows Bitcoin users to use decentralized applications (dapps) and DeFi services of the Ethereum ecosystem. The interoperable blockchain sector is critical to the future success of the industry.
Another benefit of blockchain bridges is improved scalability. Some blockchain bridges can handle a large number of transactions, increasing efficiency. For example, the Ethereum-Polygon Bridge is a decentralized two-way bridge that works as a scaling solution for the Ethereum network. As a result, users can benefit from faster transactions and lower transaction costs.
Risks of blockchain bridges
At the same time, blockchain bridges have certain limitations. In the past, attackers exploited the smart contract vulnerability of some cross-chain bridges and misappropriated huge amounts of cryptocurrency.
Custodial bridges may expose users to custodial risk. A centralized organization that owns a custodial bridge can theoretically steal users' funds. When using custodial bridges, choose well-known brands with a long-standing reputation.
Another potential technical limitation is transaction speed. A single-chain bandwidth problem can hinder the overall interoperability of blockchains.
While a bridge can reduce load on a busy network, moving assets to another network does not solve the scalability problem, as users will not always have access to the same set of decentralized applications and services. For example, some decentralized Ethereum applications are not available on Polygon Bridge, which limits its scaling efficiency.
Finally, blockchain bridges can expose the underlying protocols to risks associated with inconsistent security levels. Because blockchain bridges connect different blockchains, the overall security of interconnected networks is only as strong as its weakest link.
What is the future of blockchain bridges?
The Internet is a revolutionary system in part because of its high interoperability. Blockchain bridges are critical to increasing interoperability and mass adoption of the blockchain industry. They enabled some important innovations by allowing users to exchange assets between many blockchain protocols. Blockchain bridges have grown significantly in number, number of users, and total volume of transactions.
The need for blockchain bridges will likely continue to grow as the Internet moves toward Web3. Future innovations can provide greater scalability and efficiency for users and developers. Innovative solutions may be developed to address safety risks associated with bridges. Blockchain bridges are an integral part of creating an interoperable, open and decentralized blockchain space.
Results
The development of the blockchain industry is driven by constant innovation. There are pioneering protocols, such as the Bitcoin and Ethereum networks, which have spawned many alternative layer 1 and layer 2 blockchains. The number of cryptocurrencies and tokens has grown exponentially.
With separate rules and technologies, they need blockchain bridges to be interconnected. A bridged blockchain ecosystem is more cohesive and interoperable, enabling better scalability and efficiency. In connection with numerous attacks on cross-chain bridges, the search for a safer and more reliable bridge design continues.