A core enabler for blockchain or DLT interoperability is the ability to atomically exchange
assets held by mutually untrusting owners on different ledgers. This atomic swap problem
has been well-studied, with the Hash Time Locked Contract (HTLC) emerging as a
canonical solution. HTLC ensures atomicity of exchange, albeit with caveats for node failure
and timeliness of claims. But a bigger limitation of HTLC is that it only applies to a model
consisting of two adversarial parties having sole ownership of a single asset in each ledger …