Skip to content

Instantly share code, notes, and snippets.


Adam Gibson AdamISZ

View GitHub Profile
AdamISZ /
Last active Oct 24, 2020
How to set up a local dev environment on regtest with btcpayserver and joinmarket for interoperability testing of payjoin

Setup paying hot wallet btcpayserver to joinmarket all on one machine, on regtest:

  1. Follow installation instructions from scratch as per: (note, there is another setup description, but it is specifically for coding and debugging, using visual studio, here:

  2. after the docker-compose up dev command specified there, run dotnet run --launch-profile Bitcoin from BTCPayServer directory (should not need to change any config)

  3. Load to get the BTCPayServer UI

  4. Create an Admin account (check the option) with a random email and password. New screen should show 'Regtest' and 'Server Settings'.

AdamISZ / API-Joinmarket
Created Jul 31, 2020
Thoughts on an RPC API for Joinmarket
View API-Joinmarket
Some blue sky thinking about Joinmarket architecture (this is about the "client" side of "client-server" in the sense used in the name of the repo; there, the "server" is the communications daemon which can run somewhere else, and I'm not suggesting changing that).
Though the idea has cropped up several times (because it is a very natural concept in software engineering, and is widely used), I started today thinking again about having something like an RPC API for a Joinmarket long-running daemon (this would be *another* daemon to the one mentioned above). Let's call it jmwalletd to distinguish from existing joinmarketd (badly named in retrospect), and called that because as you see below the idea is to bundle the services around the wallet.
The reason I started thinking about it today again, was because of SNICKER; and I'll use that as an example of how this might create benefits (along with some benefits that would exist without new functionality).
Imagine then that runs as a service or simi
AdamISZ /
Created Jun 7, 2020
Possible maker taker roles in ba29e.. JM tx
#!/usr/bin/env python3
""" This represents a brief check of mainnet transaction:
in particular, assuming the four inputs identified below as "known_ins",
i.e. there is an assumption they are co-owned by one entity, this identifies
possible combinations of the other inputs, with this set of inputs,
that matches the change output according to taker/maker role, applying a sudoku.
AdamISZ /
Last active Jun 7, 2020
Ring signatures for de-linked fidelity bonds

Fidelity Bonds in an Anonymity set

If timelocked outputs are used as fidelity bonds, there is some inevitable degradation in the anonymity of users of a system that requires such bonds. Part of this would be entirely unavoidable - in that when the utxo is spent, the CLTV nature of the scriptPubKey must be revealed, and in most scenarios this would probably watermark that the utxo was being used for a fidelity bond purpose. But what might be avoided is the tracing, or linking, of a particular utxo used repeatedly for the same purpose.

Concrete case: Joinmarket maker

To make the issue clearer, consider the specific case of Joinmarket, and the recent proposal on fidelity bonds by Chris Belcher [1]. Here, the fidelity bond would be used to sign an ephemeral identity used on a message channel. The user, having committed funds to the bond, would perforce re-use that same bond every time he reconnects to the trading pit and so what is currently a completely ephemeral identity (it can be changed as often as

View SNICKER_BIP_draft.mediawiki

  BIP: ??
  Layer: Applications
  Title: SNICKER - Simple Non-Interactive Coinjoin with Keys for Encryption Reused
  Author&#58; Adam Gibson <>
  Comments&#45;Summary&#58; No comments yet.
  Comments&#45;URI&#58; &#45;
  Status&#58; Proposed
  Type&#58; Informational
  Created&#58; &#45;

AdamISZ /
Created Jul 1, 2019
Simple Python script to find Joinmarket type transactions in blocks
#!/usr/bin/env python
from __future__ import print_function
Find/count JM transactions in blocks.
Ensure your joinmarket-clientserver virtualenv (jmvenv) is activated,
make sure your Bitcoin Core node is available and joinmarket.cfg is appropriately set.
Pass start and end block number:
`python 400000 400200`.
AdamISZ /
Created Apr 27, 2019
Multiparty symmetrical Schnorrr scriptless script swap (SSSSS)

General idea; generalise the Schnorr scriptless script atomic swap of A Poelstra to multiple parties.

We consider 3-party case with trivial generalisation. Parties are Alice, Bob, Charlie, A, B, C. Payment destinations are D_x. Transactions are TX_x. Adaptor signature secrets are t_x (scalar), T_x (point). Signatures are "sigma", adaptor signatures will be marked with '.


AdamISZ /
Created Apr 16, 2019
Tool to get keys from pre-2017 Joinmarket (no segwit or BIP39) if Bitcoin Core is not available.
from __future__ import (absolute_import, division,
print_function, unicode_literals)
from builtins import * # noqa: F401
import os
from optparse import OptionParser
from jmbase import jmprint
from jmclient import load_program_config, open_test_wallet_maybe
def get_wallet_path(file_name, wallet_dir):
# TODO: move default wallet path to ~/.joinmarket
AdamISZ /
Last active Mar 6, 2019
Compressed tx transfer

Looking for optimally minimal data transfer to send a transaction.

Just throwing this out there; I'm sure we can do better.

Some stuff should be pre-agreed by anyone following this protocol. For example:

  • Preagreed: script type (say legacy P2PKH)
  • Preagreed: version 1, locktime 0, sequence maxint-1, fee 10K sats (tweak this later)

Receiver has address AR, requests X sats.

AdamISZ /
Created Dec 27, 2018
Basic payjoin/p2ep protocol for Joinmarket wallets

Described here is a variant of what has previously been published under the name "P2EP" or Pay-to-endpoint, in which A pays B but B contributes utxos, i.e. it's a coinjoin-payment.

I'm using the term "payjoin" here to refer to using that idea, but not including a URI/endpoint specific to B, and not allowing (as a merchant would) arbitrary payments, which opens up certain problems around snooping attackers (more on this below). So payjoin just means "A pays B but B actively participates and passes across utxos as extra inputs".

I'll defer a more features-focused and non-tech friendly description of what this means to a later blogpost.

You can’t perform that action at this time.