As public blockchains continue to expand rapidly, the vision of a multi-chain future has become an undeniable reality. But this growth comes with its own set of challenges, the most pressing of which is liquidity fragmentation.
Addressing this challenge head-on, Bifrost has developed the innovative SLPx tech stack, providing a pathway towards omnichain liquid staking. By establishing Bifrost-Polkadot as the hub, Bifrost manages the liquidity in an unified way. Other chains utilize remote calls to interact with liquid staking module through cross-chain messaging.
By integrating SLPx, users gain the convenience of minting, redeeming, and swapping vTokens directly on their native chains without the need to bridge assets explicitly. For example, Astar holders can directly mint vASTR on Astar Network or Soneium, without having to bridge tokens to Bifrost.
This seamless experience is enabled by Polkadot’s native XCMP (Cross-Consensus Message Passing) protocol. Bifrost ensures these cross-chain interactions remain transparent and secure, thanks to Polkadot’s shared security model.
Limited Chain Abstraction
Bifrost has already achieved limited "chain abstraction" between Polkadot parachains, but has taken a more conservative approach when it comes to fully supporting other heterogeneous chains.
The primary reason for this is that the cross-chain infrastructure connecting Polkadot with broader heterogeneous chains is not yet mature. While multi-signature cross-chain bridges that support Polkadot and heterogeneous chains have been around for some time, these cross-chain solutions present centralization risks. We look forward to the support of native trustless bridges.
Progress Towards Trustless Bridges
To achieve better interoperability and the ultimate goal of "chain abstraction," many communities are working toward improvements:
Ethereum, in an upgrade called Altair, added a new consensus step. After the Altair upgrade, every 256 epochs (roughly 27 hours), Ethereum will select a committee of 512 validators responsible for signing finalized block headers. Light clients only need to verify that 2/3 of the committee has signed to validate a block header. To further reduce verification costs, Ethereum employs BLS (Boneh-Lynn-Shacham) technology to aggregate the signatures from the committee into a single signature.
Polkadot, to better support cross-chain bridges, developed a finality tool on top of the GRANDPA consensus, known as BEEFY (as of writing, BEEFY’s code is still being finalized). After the Polkadot relay chain block is finalized by GRANDPA, the BEEFY consensus adds MMR roots to the block header and performs an additional round of consensus signing. With BEEFY, light clients will only need to validate the BEEFY signature, without delving into the complexities of GRANDPA. The most important feature of BEEFY’s signature format is that it is fully compatible with Ethereum, facilitating validation on the Ethereum side.
Here Comes Hyperbridge
The evolution now hinges on bridge engineering breakthroughs. Snowfork previously proposed a sampling algorithm to reduce verification costs, though this approach has not been implemented. The sampling algorithm sacrifices accuracy in exchange for reduced verification costs. Hyperbridge has taken over and implemented a more thorough solution to scale light client verification.
HyperBridge’s approach involves:
- Using Parachain Cores as computational units to distribute block header verification tasks across multiple cores for parallel processing.
- Aggregating verification structures of multiple chains into a single ZK proof using recursive SNARK circuits, enabling low-cost validation on the target chain. This principle is akin to ZK Rollups.
- Using KCG’s Verkle Trie structure, HyperBridge reduces the state proof size by over 90%, supporting batch verification.
- Permanently storing all validated block headers and historical states, so that light clients can asynchronously request specific historical data via the ISMP protocol, without needing real-time synchronization of the entire chain data.
HyperBridge currently supports bridging between Polkadot Parachains and Ethereum, BNB Chain, BASE, Gnosis, Optimism, and Arbitrum, with plans to support more EVM and non-EVM chains.
With HyperBridge's support, vDOT and vBNC can now be traded on Ethereum, BNB Chain, Base, Arbitrum, and Optimism, allowing participation in DeFi opportunities. In the future, based on Bifrost’s SLPx techstack, users will be able to mint, redeem, and swap vDOT, vBNC, and other vTokens on EVM chains.
A Borderless DeFi Future
The expansion of advanced cross-chain infrastructure like HyperBridge’s ZK-based light clients will gradually erase blockchain boundaries. Anyone accessing Bifrost from any chain will experience minting and circulation of vTokens as naturally as sending an email—the underlying HyperBridge ZK proof engine operates silently, while the front-end interaction is entirely "chain-agnostic."
The boundaries between chains will fade into the background, with Bifrost and HyperBridge paving the way for this future. When users no longer perceive the existence of "cross-chain" operations, decentralized finance will finally open the door to the mainstream world.