📄️ Consensus Verification
Union's underlying security model is based on consensus verification, which is the industry standard for secure bridging. When we bridge, each transaction is verified to originate from the counterparty chain. We can formulate the problem as:
Light client-based bridging is the future of blockchain infrastructure, forming the basis of horizontal scalability. However, just light clients do not take into account many attack vectors and edge cases, for example:
📄️ Permissionless versus Trustless
In web3, many protocols are permissionless in some form or another. It can refer to being able to interact with the contracts directly, without requiring some form of authorization. Ethereum transfers are permissionless for example, as you do not need to be whitelisted to create a wallet and transfer coins. USDC is permissioned, but by default, anyone is allowed to transfer USDC. Wallets can be blacklisted and frozen by Circle, so the contracts are permissioned, and trusted by Circle with full admin rights. CCTP is built on the same principles, open by default, but fully trusted and permissioned.