Welcome to the NZRT Wiki Podcast. Today we’re looking at Chain Fusion & Cross-Chain.

Let’s start by unpacking what chain fusion actually means, because the term gets used in a couple of different ways. At its most specific, Chain Fusion is a concept from a platform called the Internet Computer Protocol, or ICP. ICP’s version of chain fusion lets smart contracts running on its network directly read and write to other blockchains — like Bitcoin, Ethereum, or Base — without relying on external bridges or trusted third parties. More broadly though, you can think of chain fusion as the idea of weaving multiple independent blockchains into a single piece of smart contract logic. One contract, multiple chains, all coordinated simultaneously.

So how does ICP actually pull this off? There are two key technologies at play. The first is called Threshold ECDSA, or tECDSA. What this means in practice is that an ICP smart contract — called a canister — can hold and control cryptographic keys in a distributed way. No single node holds the complete private key. Instead, it’s split across many nodes using threshold cryptography, and they cooperate to sign transactions. The result is that an ICP canister can own and operate an Ethereum wallet natively — signing and broadcasting Ethereum transactions — without any centralised custodian or external bridge involved.

The second technology is HTTP Outcalls. This lets ICP canisters reach out to external web services directly from within the smart contract environment. That includes Ethereum and Base node endpoints. So a canister can check token balances, read contract events, and react to on-chain activity happening on those other networks.

If you picture the architecture, an ICP canister sits in the middle. On one side it’s reading state from Base or Ethereum through a service like Alchemy. On the other side it’s signing and broadcasting transactions back to those networks via the distributed key scheme. For NZRT, this is technically exciting because it could allow autonomous token operations without a centralised server or private key holder — but it’s pre-mainnet for our use case, so it stays on the radar rather than the immediate roadmap.

Now let’s talk about something more immediately relevant — the bridge between Base and Ethereum mainnet. NZRT currently deploys the ITSL token on Base, which is Coinbase’s Layer 2 network built on the OP Stack. Understanding how assets move between these two networks matters for things like migrating liquidity or accepting revenue payments from mainnet wallets.

The native connection is called the OP Stack Canonical Bridge. Moving assets from Ethereum mainnet down to Base takes roughly one to three minutes. Moving assets the other way — from Base back up to mainnet — takes seven days. That delay exists because OP Stack uses an optimistic rollup model, where transactions are assumed valid but anyone can challenge them during a fraud proof window. It is the core security model of the system.

If you need faster movement from Base back to mainnet, third-party bridges can help. There are three worth knowing about. Across Protocol uses an intent-based model and is known for being fast and low cost. Stargate, built on LayerZero, uses unified liquidity pools and supports many chains. Hop Protocol is purpose-built for OP Stack Layer 2 networks. The trade-off with any of these is that you’re accepting additional trust assumptions beyond the canonical bridge — the canonical bridge has no extra counterparty risk, while third-party bridges introduce their own smart contract risk.

For cross-chain messaging more broadly, there are three major protocols to understand. The first is Chainlink CCIP, the Cross-Chain Interoperability Protocol. It uses Chainlink’s oracle network to validate and relay messages across chains. It’s enterprise-grade and well-suited to regulated environments and high-value transfers, though it comes at a higher cost and requires paying fees in Chainlink’s own token.

The second is LayerZero. It supports over seventy chains and uses what are called Decentralised Verifier Networks to attest messages. One of its standout features is the Omnichain Fungible Token standard — OFT — which lets an ERC-20 token like ITSL exist natively on multiple chains at the same time rather than being wrapped or bridged. That makes it a compelling option if ITSL ever needs to expand beyond Base.

The third is Wormhole. It uses a network of nineteen validators and is particularly strong for projects that need to reach non-EVM chains like Solana, Sui, or Aptos. It had a significant exploit in 2022, though the funds were fully repaid.

So where does all of this leave NZRT? For ITSL, the current recommendation is to stay single-chain on Base until the mainnet launch is complete. If investor demand grows to the point where wholesale investors want to buy ITSL without bridging from Ethereum mainnet, LayerZero’s OFT standard is the leading candidate to evaluate after launch. On the consulting side, cross-chain architecture is a genuine billable advisory area for ICS — helping clients choose between these protocols, integrate CCIP for regulated token transfers, or design multi-chain token architectures from the ground up.

That’s it for this episode of the NZRT Wiki Podcast. Thanks for listening.