In this post, I will describe how to bridge assets from one blockchain to another without having too much trust in any single party. We will focus on trustless, decentralized systems that don’t use third parties or central validators.
If safety is your concern when it comes to transactions between chains, this article is going to highlight trustless assumption approaches to bridging assets.
Overview
In blockchain and DeFi ecosystems, the term “bridging” entails the transfer of assets or data from one blockchain to another. The Ethereum, Solana, and Polygon ecosystems operate independently, which makes the existence of bridges critical for interoperability as they assist in cross-chain communications.
Most of these bridges are built on centralized validators or trusted third parties which leads to risks and challenges of censorship, fraud, or theft. Hence, the goal is to explore evolving bridge designs that seeks to use minimal trust assumptions without sacrificing any security or efficiency.
The Importance of Trust Assumptions
Trust assumptions outline how much a user has to depend on external people or systems to ensure that a bridge is functioning correctly and securely. Users in high trust systems have to depend on validators or relayers acting in good faith.
However, history has shown that this form of trust is fragile, with numerous bridges being hacked, including the Ronin and Wormhole exploits which resulted in hundreds of millions in losses. Trust minimization focuses on reducing the reliance on intermediaries by creating bridges that are more secure and decentralized.
Framework for Trust-Minimized Bridging
In order to do bridging with minimal trust, there are specific design and security principles developers and users must adhere to:
1. Employ Light Clients or Zero Knowledge Proofs
Light clients allow the verifying of one blockchain’s state from another without relying on a trustful entity. Ethereum’s light client, for instance, can confirm the occurrence of certain transactions on other chains using headers and Merkle proofs.
ZKPs (Zero-Knowledge Proofs) also ensure confirmation of information without the need to share all data, for example claiming that a particular blockchain’s information is valid.
By using succinct proofs that can be verified on-chain, zkBridge and zkSync are almost achieving entirely trustless bridges.
2. Avoid Centralized Sets of Validators
A large portion of bridges are built on top of a multisig wallet or a small group of validators that watch over one chain and authorize transactions on the other.
This creates a very noticeable trust bottleneck. It is much better for bridges to have multi validator sets that focus on avoiding collusion through mechanisms like proof-of-stake consensus and incentivized game theory.
For instance, the IBC (Inter-Blockchain Communication) protocol within Cosmos supports trust-less direct verification of consensus states between chains, which enables them to confirm each other’s consensus state without resorting to trusted third parties.
3. Emphasize Open Source and Transparent Operations
All trust-minimized systems must operate in a fully transparent manner. Everything from bridge code to its processes needs to be open-sourced, so thorough audits can be performed, giving the public the chance to evaluate and confirm their operations. Regular security audits and bug bounties provide additional security measures.
This level of transparency ensures that all system flaws, along with the gaps that can be exploited for trust dependencies, are laid bare and therefore helps boost user confidence while providing systems the chance to strengthen their ecosystems.
4. Restrict Duration of Holding Bridged Assets
Even trust-minimized bridges come with their own risks, therefore users should ensure that they do not hold large amounts of bridged assets for longer durations of time.
Counterparty risk is always introduced when wrapping assets like wBTC on Ethereum. Users should favor native asset transfers via canonical bridges and infrastructures like Chainlink’s CCIP that are designed to minimize exposure to wrapped or synthetic tokens.
Emerging Solutions to Bridging That Reduced Trust
There are several new solutions that actively work towards minimizing trust in bridging:
- IBC (Inter-Blockchain Communication): Allows direct communication between chains within the cosmos ecosystem using minimal assumptions.
- zkBridge (Polyhedra, Succinct): Enables secure message passing with zero-knowledge proofs.
- Chainlink CCIP: Strives for secure universal cross-chain communication and provides strong failover mechanisms.
- LayerZero: Gives trust a minimum bound with the introduction of the “Ultra Light Node” model.
These projects focus on cryptographic assurances as opposed to social or institutional trust for building newer generation of bridges.
Final Thoughts
At this stage, the ability to securely and reliably connect disparate systems and platforms with minimal trust dependencies is critical for the establishment of a robust multi-chain future.
All current implementations remain deeply tethered to the well-marked paths of technical and usability challenges, albeit in a defined direction: centralization around intermediaries is being abandoned in favor of cryptographic trustlessness.
From this perspective, it includes every end user who must be active in avoiding using recommended bridges that do not embrace transparency and decentralization.
For developers, it’s a unique opportunity to pioneer community-driven infrastructure fostered on minimal trust, solid guarantees, and decentralization. Only at such a stage will the burgeoning blockchain ecosystem gain true interoperability.
