Trust-minimized bridging: proof-based vs committee-based and DA layers
Thread643 words
Compares proof-based and committee-based bridges on trust minimization and generalizability. Argues proof-based bridges still trust connected chain consensus and that shared DA layers with light clients could enable true trust minimization.
Key claims
Committee-based bridges generalize better, proof-based ones minimize trust more
Validity proof bridges are generally viewed as more secure than fraud proof bridges
Shared DA layers may be the key to trust-minimized cross-chain tech
0/ I recently posted a 馃У on @SuccinctLabs' Telepathy bridge and covered both @LayerZero_Labs & @axelarcore 馃寜
today I want to add some thoughts on trust-minimized bridging & the future of cross-chain interoperability 馃敭
a 馃У (0/22) 馃憞
1/ as the below overview chart that I already used in one of my recent bridging threads shows, there are two main types of bridges (proof based & committee based)
2/ there are pros & cons to both types of bridging solutions. Generally, they can be assessed via two key metrics:
馃敼 Trust minimization (concerning participation, permissionless-ness, collusion & censorship resistance)
馃敼 Generalizability/Customizability of the solution
3/ committee-based bridging solutions tend to have an edge in generalizability, allowing bridging between many chains.
with proof-based systems, the development overhead & degree of complexity involved in expanding to new networks is often higher
4/ it's also worth noting that networks based on Proof-of-Stake (PoS) such as @axelarcore or leveraging decentralized oracle networks (in conjunction with relayers) like @LayerZero_Labs, are often considered more secure than multisig & multi-party computation (MPC) based bridges
5/ in the context of proof-based solutions, validity proof based bridges are often viewed as more secure than fraud proof-based systems
6/ the recent emergence of #rollups has also spawned a new generation of cross-rollup bridges, focused purely on L2 applications. Building on native L1 to #L2 communication (through the rollup contracts), these bridges can provide trust-minimized bridging
7/ wait, what? 馃
"trust-minimization" is a key term in the context of bridging. I will talk about it more later in this thread
8/ but first, it's important to understand that current proof-based and committee-based bridging solutions are not fully trust-minimized
9/ because even with proof based systems need to trust the consensus of the connected chains
x.com/expctchaos/status/1663563768838885380
10/ this need for proofs for consensus on a specific state on the connected chains is primarily due to data availability constraints
11/ this limitation can be mitigated by making bridging chain transactions available on shared data availability solutions like @CelestiaOrg, @eigencloud's #EigenDA or @AvailProject
12/ this allows independent parties to validate cross-chain transactions and related state transitions directly on the DA layer, without having to trust the validators involved in the bridging chains' consensus
13/ this can be done by running a light client for the DA layer(s) that can subsequently perform DAS on the raw data that rollups post to the DA layer. This will enable the system running the light client to verify state information of other rollups build on that DA layer
14/ for true trust minimization, it's not just about making data available, but also about ensuring efficient validation. Thus, an independent party must be able to fetch the cross-chain transactions and reproduce state transitions in a time- and cost-effective manner
15/ an instance of true trust minimization can be seen with rollup bridges. Here, the rollup chain makes data available on the main chain (like #Ethereum) by posting its transactions and corresponding state transitions
16/ trust minimization across heterogenous chains with different consensus mechanisms remains a challenge. However, shared data availability layers may significantly influence the future of trust-minimized cross-chain technology
17/ for instance, @CelestiaOrg describes trust-minimized bridges as those requiring no intermediary, committee, or honest majority assumption to ensure fund security. Existing examples include bridges between #Ethereum and rollups built upon it
18/ with @CelestiaOrg and other data availability layers, we can anticipate trust-minimized bridging amongst "clusters" of #rollups at an unprecedented scale
For more insights, consider reading this post 馃憞blog.celestia.org/clusters/
19/ if you want to learn more about how DA layers like @CelestiaOrg, @AvailProject or @eigencloud's EigenDA work? 馃
check my 馃У below 馃憞
x.com/expctchaos/status/1663213648121307141
20/ if you want to know more about light client-based state verification via zero-knowledge proofs as a solution to the bridging problem, check my thread below 馃憞
x.com/expctchaos/status/1663563723146145798
21/ and @LayerZero_Labs is covered here 馃憞
x.com/expctchaos/status/1648038651178409984
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