Meta Description: Blockchain bridges facilitate the transfer of assets and data between two independent chains with vastly differing technological underpinning
Any Web3 protocol with its eyes set on real interoperability would, without a doubt, include developing and deploying bridges to other networks, just as did Polkadot.
What is a blockchain bridge?
Blockchain bridges facilitate the transfer of assets and data between two independent chains with vastly differing technological underpinnings. No two bridges are ever the same, and they are grouped based on the level of centralization that they offer.
On one hand, there are fully centralized bridges controlled by some third party that each chain must trust, and on the other, they can be decentralized. It is somewhat unsurprising that Polkadot prefers this latter way.
Centralized bridges have traditionally been a massive source of theft since their intermediaries are known to misuse cash in their custody. These early prototypes of bridges were hamstrung by their reliance on third-party data and a lack of regulatory control.
Why does Polkadot need external bridging?
Bridges play an important role in the success of Polkadot throughout Web3, not just in maintaining and exploiting its own ecosystem. They allow Polkadot to reach out of its walled garden, which is important because Polkadot needs to help its users interact with all the other wonderful stuff out there.
Level Layer 0 or Layer 1 blockchains coexist in independent contexts, under different regulations. Bridges tear down walls with the opening of:
Consensus mechanisms
This isolation forbids the native intercommunication between them, and an asset cannot be readily flowed across the chasm.
Interchain Transfer
Allows users to transfer assets across different blockchain networks without any hassle.
Diverse dApp access
The unique characteristics of all different chains can be harnessed by the dApps themselves to enhance their functionality and create the possibility for innovation.
User Accessibility
Bridges aid in the discovery of new platforms and in leveraging blockchain ecosystems.
BEEFY – an important milestone
You may have seen mentions of BEEFY floating around in the various Polkadot-themed social media accounts and wondered what it is.
BEEFY stands for "Bridge Efficiency Enabling Finality Yielder." It finally went live on Polkadot only recently, and the news sent ripples of excitement through the ecosystem.
The protocol allows swift connection between the central Relay Chain of Polkadot and "foreign" blockchains, like Ethereum. This allows members of remote networks to verify the finality proofs created by Polkadot's Relay Chain Validators. Or, to put it simply, the clients on the Ethereum network ought to be able to verify that the Polkadot network is in some state.
This incurs excessive expenses in storing all information needed to verify the status of the remote chain. BEEFY offers a lightweight and efficient solution to both challenges.
BEEFY – an upgrade on GRANDPA
BEEFY is constructed on top of the already existing protocol of GRANDPA and uses a consensus extension and a light client protocol to make available a more dynamic solution with smaller consensus justifications and improved communication between nodes.
It improves the efficiency and reliability of cross-chain communication within the Polkadot ecosystem by providing a lightweight solution that works with a wide range of target chains.
A significant milestone: bridging to Kusama
Polkadot has been hosting the Bridge Hub system parachain since 2023.
It has all bridges in its runtime, which enables it to have secure bridging with other networks. Its security relies solely on the Relay Chain. The governance is directly derived from the DOT token.
Significantly, it has already hit one notable milestone by serving as a launchpad for the Polkadot <> Kusama bridge, the very first trustless bridge for the ecosystem and among the most secure designs in space.
This bridge will be a milestone in blockchain technology, acting as a relevant example of full interoperability in practice. It realizes the concept of the interlinked blockchain environment without any fractures.
Use of the bridge
It demonstrates how any form of an asset living on-chain can easily be transferred between Polkadot and Kusama networks, furthering liquidity enhancement and opening new paths to decentralized applications.
What makes the Polkadot <> Kusama bridge so important is beyond what, at this very moment, it can do. It sets a very strong precedent for all future blockchain developments, saying that there is the ability to do more complex and more integrated blockchain applications. The challenge and considerations taken while developing it brought very valuable lessons for consumers and developers alike, contributing to the debate over scalability, security, and user experience in blockchain technology.
There are also all the technical elements within the Bridge Hub to allow developers to experiment with an array of further bridging possibilities using Polkadot as the source (or origin).
Snowbridge: A Trustless Path to Ethereum
The Snowbridge is another of the central bridging updates to the Polkadot ecosystem and one that is long-anticipated. It is a team-led effort at Snowfork with the backing of Parity Technologies.
Currently, all Ethereum assets in the Polkadot ecosystem flow through bridges dependent on third-party signatures, still the normal approach across Web3: bridge or governance signatures from private keys, token-holders, or validators that fit neither the Polkadot nor Ethereum validator sets.
What does this mean?
This means that currently, all of the parachains and dapps in the Polkadot ecosystem, through which these assets flow, are hampered by their trust model with third parties, and not just the Polkadot Relay Chain for security—a detrimental influence on the entire scope of Polkadot.
Snowbridge's methodology is completely trustless, only relying on signatures from first-party Polkadot and Ethereum validators, and totally transparent, permissionless, and auditable blockchain logic. It uses the same Bridge Hub as the Polkadot <> Kusama bridge. With Snowbridge's impending launch, huge potential opens up for Polkadot to expand into a new wave of engagements with Ethereum.
Hyperbridge: An alternative way forward
Polytope Labs invented the Hyperbridge technology, short for 'hyper-scalability bridge'. This bridge, in a nutshell, is designed to provide safe and state-proven interoperability across all blockchains and consensus protocols—not just Polkadot <> Ethereum. It works by using its own chain that verifies cryptography on behalf of other blockchains.
A secure bridge
Polytope Labs creates a secure bridge between blockchains by verifying consensus, faults in consensus, state proofs, and state transitions. This is, however, a complex set of operations, always prone to threats of centralization or attacks due to human error.
What Polytope does is create an architecture-enabled coprocessor model by shifting computational weight off-chain and only bringing on-chain the cryptographic proofs of execution. Through numerous parachains, the burden is distributed and Polkadot takes the role of the computing layer, minimizing bottlenecks.
It is for that reason that according to the grandiose aspirations of Hyperbridge, Polkadot will serve as Ethereum's data availability layer.
Conclusion: Polkadot’s Bridge-built future
Blockchain Bridges are critical lifelines in the intricate web of interconnected blockchain networks. Polkadot is devoted to investigating issues in a way that enables trustless and decentralized bridging while maintaining Relay Chain-level security and scalability.
To this aim, it has already opened up the Polkadot <> Kusama bridge, and with Snowbridge and Hyperbridge perhaps coming on quickly, there is much for both the existing community and future users to look forward to. Polkadot's approach to bridging in Web3 is truly pioneering and groundbreaking, and it is likely to stand the test of time.
Frequently asked questions
What are blockchain bridges?
Blockchain bridges move assets and data from one independent blockchain network, using different technologies and consensus procedures, to another. They are used to communicate and interoperate with different blockchains otherwise separated.
Why are blockchain bridges important for Web3?
Bridges are an implementation strategy that would allow interoperation between blockchains, thereby giving users the capability to transfer assets, access a host of decentralized applications, and discover new platforms. In effect, this drives innovation but makes blockchain ecosystems more usable and productive.
How does Polkadot bridge with other chains?
Polkadot aims to provide bridges that are decentralized and trustless; this means no third-party middlemen. This means that Polkadot achieves greater security and efficiency in cross-chain communication during interactions with other blockchain networks.
