Custodian Bridge for Non-BTC Tokens

Background

Vaulta and EVM

We use the Vaulta (https://www.vaulta.com/) blockchain network. The Vaulta blockchain is a next-generation Layer-1 built for speed, scale and finality. Your transfers, swaps, and app interactions happen almost instantly with low (or no) fees.

Vaulta EVM is a powerful feature of the Vaulta blockchain that brings the best of Ethereum's capabilities to the Vaulta ecosystem. It allows you to use popular Ethereum-based applications (dApps) on Vaulta, benefiting from faster speeds, lower costs, and a more eco-friendly environment.

Exsat EVM

Vaulta EVM technology allow entities to run their own EVM layers on the Vaulta blockchain. Exsat runs it’s own EVM layer, the Exsat EVM.

Exsat EVM Mainnet

RPC: https://evm.exsat.network/

Block explorer: https://scan.exsat.network/

Exsat EVM Testnet

RPC: https://evm-tst3.exsat.network/

Block explorer: https://scan-testnet.exsat.network/

Reserved Address

Each Vaulta account has a mapped reserved EVM address. The rule is using the uint64 value of the Vaulta name as the last 8 bytes of the EVM address, and then pad the rest with 0xbb. E.g. the name “eosio.evm” is mapped to “0xbbbbbbbbbbbbbbbbbbbbbbbb5530ea015b900000”

Contracts on Vaulta and EVM can communicate with each other through the cross chain message mechanism. This enable us to programmatically coordinate operations in both domain. The actions will usually be organized in a single Vaulta transaction so that they are atomic.

Please check Brief Intro to the Cross-Chain Communication for more details.

Trustless Bridge

The Vaulta EVM solution contains designs for bridges to move tokens between the Vaulta native and EVM domain. The support for the native token of the EVM and other tokens will be different.

Please check the following docs for more details.

Trustless Bridge for Native Tokens

Trustless Bridge For ERC20 Tokens

The Bridge

Basically, we have a off chain service to connect the custodian service and the contracts on Vaulta. The rest is handled by a bunch of contracts on Vaulta and EVM.

Deposit ERC20 token to user address.

Withdraw ERC20 token.

User Managed by dApp

Deposit ERC20 token to dApp.