Union completes trusted setup to pave the way for trustless cross-chain DeFi

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Union just set a new record for zero-knowledge infrastructure. Its Groth16 trusted setup ceremony closed with 4,664 verified contributions — surpassing Manta Network’s 2023 record — and another 4,590 are still in the queue. This establishes the cryptographic foundation for validating consensus and cross-chain messages with succinct validity proofs.

Trusted setup ceremonies are crucial to zero-knowledge proving systems. Union enables it to act as a “blockchain of blockchains,” offering verifiable message passing and asset transfers across Ethereum, Cosmos, Arbitrum, Babylon and even Bitcoin L2s — all without relying on centralized actors.

Union Chief Technology Officer Cor Pruijs emphasized the significance: “Union’s circuit having the largest Groth16 trusted setup ceremony ever means that it has the smallest honesty assumption of all.”

“Honesty assumption” refers to the minimum number of participants who must act honestly (i.e. not leak or reuse their private randomness) for the resulting cryptographic parameters to remain secure.

Ethereum’s KZG Ceremony for the Proto-Danksharding upgrade used to scale rollups holds the record for most participants in any trusted setup. However, that ceremony’s computational demands were far lower, making Union’s scale even more impressive.

Despite the complexity of such cryptographic pipelines, contributors needed only to queue up and complete the computation when their turn came, with each result verified and added sequentially to the setup.

While Ethereum’s KZG setup was limited to data availability for rollups, Union’s underpins full cross-chain consensus verification. The design bears modular features:

1. CometBLS, a modified CometBFT, is a data-light consensus mechanism that aggregates validator signatures for efficient onchain verification.
2. A permissionless prover network, Galois, generates zk proofs in under seven seconds.
3. Voyager (a decentralized relayer system) moves proofs and state data between source and destination chains.

The result is trust-minimized interoperability that works across execution environments — be it EVM, CosmWasm, SVM or MoveVM. That’s a gamechanger for developers building across chains who want fast finality and unified liquidity without compromising on security.

For comparison, Wormhole relies on a multisig model governed by a fixed set of 19 “Guardians,” where messages are only valid if signed by a supermajority (13/19). Axelar uses a validator-based architecture secured by economic incentives, and requires its nodes to run full chain nodes for each connected network.

Union’s approach inherits core principles from the Inter-Blockchain Communication (IBC) protocol but effectively virtualizes IBC through zk proofs. This architecture removes reliance on whitelisting actors, and lets the interop layer scale horizontally across chains without replicating full node infrastructure, according to Union Labs CEO Karel Kubat.

“The key solution here is actually generating a [zero-knowledge proof] for your consensus updates instead of doing it in the contract itself…So if a network has 100 validators, 1000, or a million, it doesn’t really matter, because the ZKP has a constant cost associated with it,” Kubat said on the 0xResearch podcast earlier this year.

It also allows for permissionless solvers: Any participant can monitor chains, generate consensus proofs and submit them to the network.

For even faster settlement, Union supports intents, enabling solvers to front capital and fill user transactions almost instantly. Partners like Aori route these fills, with solvers taking on the finality risk. That should serve both latency-sensitive apps and more high-value, security-conscious use cases. Importantly, both are possible using one API, thus unifying general message passing and intents in a single integration.

Kubat expects Union will be about as cheap as Across Protocol, with only around 20 transfers occurring at the same time. “That’s actually quite amazing with all of the cryptography happening under the hood,” he said.

After quietly supporting Babylon Genesis with a proof-of-authority testnet, next up is Union’s mainnet. For crypto natives, the potential implications are frictionless, cross-chain dapps without fragmented UX or trust in multisigs. If Union delivers on its promises, this might be the first interop layer that actually feels like using one unified chain.

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