RubenSomsen

Liquid P2P Loans

This is a variation of the Hodl Hodl contract design for Liquid, but without an arbitrator (not counting Liquid itself). It's pretty simple and similar ideas exist, but it seemed interesting enough to write up and spur some conversation.

I'll begin by explaining the high level concept. For the full details, please examine the steps in the diagram below.

Concept

A contract where the Borrower puts up 1.5x collateral (e.g. 1.5 L-BTC) in order to borrow another asset (e.g. $10k USDT, if we assume that's the price of 1 L-BTC). The borrower can reclaim the collateral if they pay back the loan before expiry. If expiry is reached, the collateral goes to the Lender.

Use cases

• Spending L-BTC without necessarily selling, which

RubenSomsen

SAS: Succinct Atomic Swap

Works today with [single signer ECDSA adaptor signatures][0], or with Schnorr + MuSig.
Other than the explanation below, there's also a diagram and a video.

 
Advantages:

• Requires merely two on-chain transactions for successful completion, as opposed to four
• Scriptless, and one of the chains doesn't need to support timelocks
• Can be used for efficient privacy swaps, e.g. [Payswap][1]

RubenSomsen

Introduction

I'm Ruben Somsen, Bitcoin Sorcerer. I do protocol design in order to enhance Bitcoin.

I'm sponsored by Spiral, Superlunar/Gemini, HRF, and am currently working on Silent Payments with Josie and assisting Davidson with the implementation of Proof-of-Work fraud proofs into Floresta.

I also help maintain the bitcoin-dev mailing list, am a BIP editor, co-hosted the Unhashed Podcast, founded the Seoul Bitcoin Meetup in 2014, actively co-organizing BitDevs Amsterdam, and on the layer two funding sub-committee of OpenSats.

You can find me on Twitter, Mastodon, and Telegram. You can also join [this Te

RubenSomsen

Blind Merged Mining with covenants ( sighash_anyprevout / op_ctv )

Update: the content of this gist is also explained in this Spacechains video.

This write-up was also published on bitcoin-dev.

Blind Merged Mining (BMM) is the idea of committing the hash of another blockchain into a unique location on the Bitcoin blockchain, and paying a Bitcoin fee to miners for the privilege of deciding this hash and capturing the fees inside the other blockchain. Since miners don’t have to know what the hash represents and are simply incentivized to choose the highest bidder, it requires no extra validation on their part (“blind”). This idea was originally conceived of by Paul Sztorc, but required a specific soft fork. [0]

In essence, BMM is a mechanism that allows external blockchains (altcoins, tokens) to outsource their mining to the Bitcoin blockchain. Instead of burning electricity with ASICs, th