Concurrency and Privacy Challenges for Multi-hop HTLCs
summary
Proposes replacing a single shared HTLC preimage with an XOR-combined chain of independent hashes plus non-interactive zero-knowledge proofs so intermediaries verify well-formedness without learning payment values; proofs are sent over the anonymous channel and keep contracts mutually independent while remaining compatible with Bitcoin script and SHA-256. Shows liveness requires a trade-off: a global transaction identifier total order yields a non-blocking forwarder but leaks information, so full privacy and non-blocking concurrency are provably incompatible under the model.
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chapters (12)
- 0:00Intro
- 0:24Smart contract ecosystem
- 1:42Payment Channel Networks for Off-chain Transactions
- 2:10Off-chain PCNs Computation Model
- 4:04Hash Time-Lock Contracts for Atomicity
- 4:52Atomic Transactions
- 7:12System and Security Properties
- 9:27Our solution: Multi-Hop HTLC
- 10:17Multi-Hop HTLC: Basic protocol
- 15:20Concurrency in Multi-Hop HTLCs
- 19:59Concurrency Tradeoff
- 21:01Multi-Hop HTLCs: Looking ahead
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