RubenSomsen

SwiftSync

Near-stateless, fully parallelizable validation of the Bitcoin blockchain with hints about which outputs remain unspent. All other inputs/outputs are efficiently crossed off inside a single hash aggregate that only reaches zero if validation was successful and the hints were correct.

15-minute talk summarizing the protocol

Introduction

Validation is at the heart of Bitcoin. Any improvements in validation speed will have a direct impact on the scalability of the system, including everything that is built on top of it. For this reason improving validation performance may be one of the most important things we can do.

RobinLinus

OP_CAT Enables Scalar Multiplication for EC Points

CAT can reduce curve point scalar multiplication to a subtraction in the scalar field.

Subtraction of field elements can probably be emulated in less than 250 (?) opcodes. For now, let's assume we had an (emulated) opcode, op_scalar_sub, for subtracting two elements of the scalar field of secp256k1.

Given secp's generator G, we want to compute for some scalar r the point R = rG

That is possible by hacking it into a Schnorr signature (R,s) for the key P = xG = 1G = G

RubenSomsen