Re: [bitcoin-dev] Detailed protocol design for routed multi-transaction CoinSwap

2020-08-20 Thread Nadav Kohen via bitcoin-dev
Hey Chris and all, Looking good :) I have one major concern though >q = EC privkey generated by maker >Q = q.G = EC pubkey published by maker > >p = nonce generated by taker >P = p.G = nonce point calculated by taker > >R = Q + P = pubkey used in bitcoin transaction > =

Re: [bitcoin-dev] Revisiting squaredness tiebreaker for R point in BIP340

2020-08-12 Thread Nadav Kohen via bitcoin-dev
Hello Pieter and all, I am one of the maintainers of Bitcoin-S[1] and I maintain our secp256k1 bindings (via JNI) as well as our (inefficient) bouncy castle fallback implementations of all secp256k1 functionality we depend on including Schnorr signatures. In light of this new information that

Re: [bitcoin-dev] Statechain implementations

2020-04-03 Thread Nadav Kohen via bitcoin-dev
Hey all, So my main concern with the proposal as written is that the Statechain Entity (SE) can untraceably scam its users with the following attack: 1) Buy the utxo (have it transferred to a key it knows), this first step can be skipped if the utxo was created by the SE. 2) Transfer the UTXO to

Re: [bitcoin-dev] Smart Contracts Unchained

2019-04-18 Thread Nadav Kohen via bitcoin-dev
Hi all! I've been thinking a lot about how to add the benefits that lightning provides in terms of privacy and speed to the smart contracts unchained setup. The high-level idea is to utilize the fact that a lightning channel already has on-chain funds locked up, and if parties cooperate, some of