LLFourn

My review of Practical Schnorr Threshold Signatures Without the Algebraic Group Model

Inline comments

Page 4

However, this is non-trival because we need to consider the PedPoP DKG and the signing protocol together. The rationale behind this is that PedPoP (like Pedersen DKG) lacks the ability to be simulated. Hence, it becomes crucial to examine the combination of the DKG and the signing

LLFourn

Unifing FROST and MuSig

There might be a secure scheme that non-interactively generates a n-of-n FROST key and from there you can interactively turn it into a t-of-n by issuing new shares (i.e. enrolment). I don't really know if this is a useful contribution even if it works. There might be some utility in not having multiple schemes but rather a one size fits all approach.

Idea

MuSig takes a "multiset" of n public keys and outputs a single aggregated key which takes n-of-n secret keys to sign. Set z_i = H(X_1,.. X_i, .. X_n, X_i) for i = 1,2, .. n.

LLFourn

OP_CTV and DLCs

Hi dlc-dev and bitcoin-dev,

tl;dr OP_CTV simplifies and improves performance of DLCs by a factor of a lot.

Introduction

Dryja introduced the idea of Discreet Log Contracts (DLC) in his breakthrough work[1]. Since then (DLC) has become an umbrella term for Bitcoin protocols that map oracle secret revelation to an on-chain transaction which apportions coins accordingly.

LLFourn

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LLFourn

sub MAIN(Int \m, Int \n, Int :$samples = 10_000) {
    my \q = 2 ** 19 - 1;
    my \m-n =  m ** n;

    # experiment should be done over a prime field so that it mirrors reality
    say "q = {q} (is-prime: {q.is-prime})";
    say "samples = {$samples}, m = {m}, n = {n}, m ^ n = {m-n}";

    sub count-collisions(@table) {
        # This line of code:

LLFourn

//! PoC style code for anticipating BIP-340 style signatures for PoC DLC stuff.
//!
//! WARNING this doesn't check that:
//!  1. Public keys have an even Y coordinate
//!  2. Public nonces have a square Y coordinate
//!
//! If the public keys are in the right form, then this should produce valid
//! BIP-340 signatures (to be fully compatible then the tag needs to be set
//! correctly).
//! Add to Cargo.toml:

LLFourn

This is a response I made to the thread that didn't make it into the archive (I think) :https://lists.linuxfoundation.org/pipermail/lightning-dev/2018-December/001752.html

---

Happy new year lightning-dev!

This topic is my main area of research at moment so I'm really happy to see a thread about it. In general I agree with ZmnSCPxj's analysis and conclusions. I'd like to add a couple of ideas to this discussion and would greatly appreciate some early peer review on them :)

HTLCs as American call options

LLFourn

class Rakudo {

    constant File $:install-to;
    constant $:checkout = '2017.07';
    constant File $:clone-to = './rakudo';
    constant GitHub $:zef-repo = 'ugexe/zef';
    constant GitHub $:repo = 'rakudo/rakudo';
    constant Bool $:debug-moar;

    static method install-deps on {

LLFourn

# So you want to pipe shell scripts to docker. But docker runs the container's command as PID 1. 
# Linux doesn't set up signal handlers for PID 1.
# This gives you the following problems:
# 1. The script can't kill itself:
echo 'kill $$; echo "Still alive"' | docker run -i --rm alpine sh 
# 2. You can't kill the script from outside with a normal kill:
echo "sleep 1000" | docker run -i --rm alpine sh & sleep 1 && kill $!
docker ps # it didn't die

#==== Solving problem 1 ====

LLFourn

BEFORE:
A 9.0422700
C 10.6984718
B 10.3635278
a 17.9581401
b 21.61539652
c 27.7105599
HEAD:
A 4.126187
C 4.918153