Trustless Ethereum Bridge

Trustless Ethereum Bridge

Next Date
November 22, 2021 → February 14, 2022
Ganesha UpadhyayaJenya PiskunovAaron Li
Live on Testnet

Progress update

Currently there are several pending tasks that needs to be completed (along with estimates) listed below:

  1. EIP-1559 update to ethereum pow verification [3 days]
  2. Limited header storage in smart contracts [1 day]
  3. Handling forks & building canonical chain for ethereum light client & TokenLockerOnHarmony to use canonical chain [5 days]
  4. Merging two redundant merkle libraries [3 days]
  5. Batch header receive functionality [1 day]
  6. MMR hardfork PR, addressing comments, getting it merged [5 days] @Ganesha Upadhyaya
  7. Unit test completion [1 week]
  8. Relayer & frontend completion [2 weeks] @Jenya Piskunov

Total #days: 39, Work resuming this week (Jan 3, 2022)

Revised launch date: TBA (will be updated by Jan 17, 2022)

Ethereum Bridge: trustless and efficient asset transfers among PoW-PoS chains

We are building a bridge for applications to access assets on Ethereum while enjoying fast transactions on Harmony. Our bridge architecture is industry leading, being gas efficient and seamless between Proof-of-Work and Proof-of-Stake chains. Inspired by Flyclient (already deployed in ZCash), our light client uses Merkle Mountain Range (MMR) and epoch syncing. Later we may employ zero-knowledge proofs such as Plonk to further compress the states of these heterogeneous chains.

Testing instructions

Weekly milestones

9/6-9/13: bug fix & localnet testing Done

  • Fixed a bug in the MMR proof generation logic related to siblings node computation. Added node index to MMR Proof RPC response and modified GetProof RPC to return MMR proof with respect to an input block number to 3872. The 3872 PR is almost ready for review this week and testnet testing.

9/13-9/30: v1.0.0 [Pre-alpha] functionality completing & unit tests DONE

  • Finalize MMR Hardfork PR 3872 and get it reviewed/merged
  • Finish HarmonyLightClient & tests
  • Migrate to hardhat with upgradability
  • Upgradable LightClients and Provers (both Harmony & Ethereum side)

9/27-TBD: v1.0.1 [Pre-Alpha] functionality completing & unit tests In-Progress

  • complete unit tests for lightclient, prover and bridge contracts on both sides
    • prover: validating header, transaction inclusion, receipt, account, log, code
    • lightclient: checkpointing, relayer add/remove, threshold
    • bridge: deposit, withdraw, execute
    • upgradability: both lightclient & bridge, gnosis-safe ownership
  • fix bridge cli & tools - DONE
  • gas cost estimation experiments for relayers and users
  • begin audit (internal+external)

10/11-TBD: v1.0.2 [Alpha] bridge ecosystem deployment In-Progress

  • specs & docs @Ganesha Upadhyaya
  • relayer client, dashboard @Jenya Piskunov
    • client: includes both eth and hmy rleays, js client with docker build, aws kms for signing key management
    • admin dashboard: list all withdraw requests from users, show relay cost, profit, trigger client to relay
  • bridge frontend & explorer @Jenya Piskunov

10/11-TBD: v1.0.3 [Alpha] testnet deployment

  • deploy eth components on harmony testnet, run kovan testnet relayer, full functionality testing
  • deploy hmy components on kovan testnet, run hmy testnet relayer, full functionality testing

10/18-TBD: v1.0.4 [Beta] mainnet deployment