Introduction to Hash Time Lock Contracts (HGLCs) in the Lightning Network

In Episode 7, we chat with Nadav Kohen of Suredbits and discuss payment points as an alternative to HTLCs on the Lightning Network.

In this conversation we cover:

• Payment points (1:55)
  - Blog post part 1
  - HTLCs (2:00)
• Timelocks (4:16)
• HTLC drawbacks (5:38)
  - Payment decorrelation
  - Wormhole attack presented in Anonymous Multi-Hop Locks for Blockchain Scalability and Interoperability (6:35)
• Point time lock contracts (PTLCs) (9:50)
  - Adaptor signatures on Schnorr
• Proof of payment (13:25)
• Invoiceless transactions (15:05)
• Hashes, pre-images, and HTLC mechanics (16:35)
• Onion analogy (18:55)
• PTLC mechanics (19:30)
• Why don’t we use PTLCs today? (22:15)
• Lightning in Scriptless Scripts posting by Andrew Poelstra March 2017
• Improving proof of payment (26:10)
• Stuckless payments (30:46)
• Spam on Lightning (35:46)
• Selling Signatures and Schnorr signatures off the main chain (36:55)
• Contingent payments (39:20)
• Escrow contracts (41:28)
• Atomic multiparty setup and payment renegotiation (46:02)
• ETA of payment points (48:02)

Thanks as always to Matthew Zipkin for the sound engineering.