Experiences Working on Layer 2 Scalability Solutions Corné Plooy Amiko Pay Experiences Working on Layer 2 Scalability Solutions Corné Plooy

A network of channels Lightning model De-centralized Internet

Nodes and Channels Lightning model De-centralized Internet

Different channel types Lightning model De-centralized Internet

Channel types Done: Ripple-style IOU “channel” Work In Progress: true Lightning channel Lightning developers: side chain Amiko Pay: emulation by escrow service More important than complexity: Missing features These things are required for Lightning

Issues / Thoughts Software complexity Transaction malleability The routing details really matter Economic modeling of the network More important than complexity: Missing features These things are required for Lightning

https://github.com/cornwarecjp/amiko-pay Thank you https://github.com/cornwarecjp/amiko-pay

Emulation by escrow services A+B TCD TCD TCD A OP_RETURN A 2 of A+B+E B A B This is the Amiko Pay microtransaction channel OP_RETURN: secure hash → Transaction Conditions Documents Time-out, transaction hash etc. 2-of-3 locked amount Normally: update by Alice / Bob Alternative: 3rd transaction signed by escrow

Required for Lightning Network Fixes for transaction malleability New SIGHASH types Lock time evaluation in script “OP_CHECKLOCKTIME” Relative lock time Optional: necessary for unlimited-lifetime micro- transaction channels More important than complexity: Missing features These things are required for Lightning

Very rough storage estimate $10 000 savings per person $1 per small transaction ___ / 10 000 unspent transactions per person 10 billion people 100 bytes per transaction ___ x 1016 bytes = 10 000 TByte = block chain size (when using block chain pruning!) Also: 10 GByte per block Hard disks: max density ~3 nm → 10 nm^2 → 1 m^2 hard disk surface → ~100 surface layers (expensive!) IF 100% of disk is used for block chain Flash:max density ~100 nm → much worse Only possibility: 3D structures (e.g. holographic)

100 x 100 TByte

Very rough storage estimate 1 channel per person 10 billion people 100 bytes per transaction ___ x 1012 bytes = 1 TByte = block chain size → Factor 10 000 reduction! Also: 10 MByte per block → Factor 1000 reduction! Hard disks: max density ~3 nm → 10 nm^2 → 10 mm^2 hard disk surface → small fraction of hard disk