Blockchain Interoperability
Direct connection
Two-way pegs
Alexei Zamyatin, Dominik Harz dominik.icon, et al.
S&P'19
ChainRelay (generalization of BTCRelay)
Issue: SPV proof
Redeem: Operators need to submit the proof of minting, or get punished (their deposits get slashed).
Dogethereum
No on-chain validation of superblocks. TrueBit-style off-chain validation.
Require two Merkle proofs (proofs of inclusions of transactions / blocks)
Issue: SPV proof
If the operator walk off with “locked” DOGE, any WOW Hodler can then burn WOW in exchange for his ETH collateral. (Described in the section 4.8 of the next paper)
Jason Teutsch (Truebit), Michael Straka (Stanford University) and Dan Boneh (Stanford University)
Improvement of Dogethereum based on: bulletproof with a cryptoeconomic mechanism
Related
Martin Westerkamp (TU Berlin)
Systems for Interoperability
Protocols for continuous interoperation among (potentially multi-)blockchains
Enis Ceyhun Alp, Eleftherios Kokoris-Kogias, Georgia Fragkouli, Bryan Ford (EPFL)
HotOS'19
Zhuotao Liu1,2 Yangxi Xiang3, Jian Shi4 Peng Gao5 Haoyu Wang3, Xusheng Xiao4,2 Bihan Wen6 Yih-Chun Hu1,2
1 UIUC, 2 HyperService Consortium, 3 Beijing University of Posts and Telecommunications, 4 Case Western Reserve University, 5 UC Berkeley, 6 Nanyang Technological University
A developer-facing programming framework (, which is applicable to Sharding) Universal State Model: a blockchain-neutral model to describe dApps
HyperService Language: a high-level language to program dApps
No control-flow operations, dynamic transaction generation (so no re-entrancy)
Universal Inter-Blockchain Protocol (UIP) for parties to co-execute cross-chain dApps
Verifiable Execution Systems provides the service to clients in typical scenarios
Network Status Blockchain as a fallback. stores the state roots of the connected chains. Horizontally shardable.
Insurance Smart Contract: a trust-free code arbitrator
UC proofs of UIP's financial atomicity, accountability, correctness guarantee
Experiment: Ethereum and Tendermint
X-chain verification of transactions: Medium IEEE Access, 2019
Peter Robinson, David Hyland-Wood, Roberto Saltini, Sandra Johnson, John Brainard (Consensys)
Coordination Blockchain: for a global time-out across sidechains. Can be Ethereum main chain or private chain.
Crosschain Coordination Contract: for each cross-chain TX, record the time-out block number and the state (started/commited/ignored)
User (e.g. an enterprise) must 1) run validators on all of the sidechains which the cross-chain transactions touches and 2) an access to a Coordination Blockchain.
Contract locking: contract call fails unless the contract is Lockable
Threshold signature for each validator set of a sidechain
Threshold = $ F + 1($ F= Byzantine fault threshold of e.g. IBFT)
Example: A variable amount atomic swap contract between sidechains unlike the HTLCs-based scheme
Hui Wang (ZhongAn Information Technology Service) et al.
IEEA'17
Kan Luo (Beihang University) et al.
QRS-C'18
Cross-chain communication by three phase commit