MAP labs - MAPBridge


Team and background:

  • Dr. Chan received the Ph.D. degree in applied mathematics from Illinois Institute of Technology, Illinois, USA in 2017. His research interests include consensus algorithms, P2P protocol, cryptography, blockchain interoperbility.
  • Dr. Seabook is based in Australia and get his Blockchain PhD. from Australian Deakin University. He has more than 15 years of professional software design, architecture and development experiences. He has worked as Chief Technology Officer and Senior Architect in Telstra, Accenture, Qantas, eBay and Citibank.
  • LYU.L holds a master degree from Tsinghua University and also a member of China national blockchain and distributed ledger committee. He has more than 13 years of experience in large-scale computing and algorithm, with many patents such as consensus algorithm and blockchain transaction.

Project and justification

This project deliver a relay bridge to connect CKB and other PoW chains. For most current bridge solutions, it need a relayer group to provide service for SPV verification. Our Map Bridge can provide a functionality that reading cross-chain information can be achieved without a relayer group. The reason for the existence of relayer group is SPV need the relayer group holding all block headers of the blockchain and provide it to any verifier who need such information. Map Bridge can provide a non-interactive, succinct proof which grows sub-linearly. We hope that MAP bridge could help CKB and other blockchains form a borderless, open ecosystem composed of heterogeneous interoperable blockchains.

High level technical specification and implementation

  • MAP-Bridge would implement a new data structure called merkle mountain range(MMR) which contain the information of all confirmed block headers. And the root of MMR would be include in the header of new mined block.
  • Map-Bridge would use ULVP to acquire non-interactive proof of POW verification of the bridged chain. ULVP is a flyclient-type verification module to verify the validity of tail block of a certain blockchain carry heaviest proof of work. The size of proof grows sub-linearly as the length of the bridged chain.
  • Once the header of tail block in a certain blockchain can be confirmed, any block header in this blockchain can be determined through the MMR branch proof, with the fact that the header of tail block contain the root of MMR including all headers.
  • Furthermore if any block header can be determined, any transaction or inner state of certain account could be verified through merkle branch proof similar to SPV(simplified payment verification).
    +Once the cross-chain data reading is complete, MAP Feeder could make sure the following cross-chain event would be triggered and thus achieve chain interoperability.

Timeline and project duration :nut_and_bolt:

Milestone 1 Implement MMR Module and ULVP(ultra-light verification protocol)

Number Deliverable Time Period
1. Implement MMR Trie Structure 1 week
2. Integrate MMR into blockheader and complete chain header storage 1 week
3. Implement ULVP based on MMR 2 weeks

Milestone 2 Implement MAP feeder and MAP-P2P

Number Deliverable Time Period
1. Implement MAP feeder 2 weeks
2. Implement MAP-P2P based on libp2p 2 weeks

Milestone 3 Intergrate ULVP and MAP feeder and complete MAP-bridge.

Number Deliverable Time Period
1. Intergrate ULVP and MAP feeder into MAP-bridge 2 weeks
2. Provide a demo show how MAP-bridge connect CKB blockchain and other POW blockchain. 1 week
3. Make document about the map-bridge 1 week

thank you for your proposal submission! Wanted to share a post that contains some challenges to implementing Flyclient in the block header of CKB, looking forward to your ideas!

Thank you for your prompt reply. We indeed find that adpoting flycilent to different POW consensus blockchain is not an easy issue. Hope we can keep in touch with you and other team to make it work.