chris-belcher

https://bitcoin.stackexchange.com/questions/29948/why-doc-says-importing-private-keys-is-so-dangerous

https://bitcoin.stackexchange.com/questions/18619/why-so-many-warnings-about-importing-private-keys

behave un-intuatively

'giving' a key to someone still means you have it

change addresses / paper wallets

chris-belcher

#jsonrpc.py from https://github.com/JoinMarket-Org/joinmarket/blob/master/joinmarket/jsonrpc.py
#copyright # Copyright (C) 2013,2015 by Daniel Kraft <d@domob.eu> and phelix / blockchained.com

import base64
import httplib
import json

class JsonRpcError(Exception):
    def __init__(self, obj):
        self.message = obj

chris-belcher

#Can override these defaults per-section.
[DEFAULT]
#Twisted's default is 30 seconds.
timeout=180
port=6697
#A single channel to join, or a list of channels: #a-bridged-channel,#some-other-channel
channels=#joinmarket
nick=JoinMarketRelay
#Can change to allow more specialized behavior.
username=jmrelay

chris-belcher

https://www.reddit.com/r/Bitcoin/comments/cgryi1/international_energy_agencys_report_on_bitcoin/

78% of bitcoin mining uses renewables https://twitter.com/C_Bendiksen/status/1068221424777814016 apparently because of their cheaper marginal cost

debunking of the nature paper https://twitter.com/nic__carter/status/1056976815032582144

https://twitter.com/Beetcoin/status/935460412262375424

https://hackernoon.com/the-reports-of-bitcoin-environmental-damage-are-garbage-5a93d32c2d7 reddit thread: https://www.reddit.com/r/Bitcoin/comments/almsef/the_reports_of_bitcoin_environmental_damage_are/

chris-belcher

How Wasabi Wallet and Samourai-Wallet-Whirlpool slightly degrade the divisibility of bitcoin

December 2018

I made this claim on twitter recently and many people wanted me to go into more detail.

Lots of privacy tech in bitcoin like coinjoin, coinswap, tumblebit and Lightning Network require many entities to come together to agree to make certain kinds of transactions. This creates a requirement that the right resources (coins) have to be in the right place,

chris-belcher

JoinMarket with off-chain fees

17/01/2019

Problem: Single JoinMarket coinjoins aren't private enough

A single JoinMarket coinjoin often doesn't hide which inputs belong to the maker(s) and which belong to the taker. This is because the coinjoin fee is included on-chain.

To tell apart takers' inputs from makers' inputs, subset matching can be used. The taker's subset is

chris-belcher

Plan to improve the privacy of JoinMarket's tumbler script

24/02/2019

JoinMarket has a tumbler application which aims to send bitcoins in a way that delinks the origin and destination.

I have some thoughts on how and why to improve the tumbler algorithm.

Feel free to bikeshed some of these parameters (averages, counts, etc), as my important points are about other stuff.

chris-belcher

edit: this scheme has serious problems, see the comments

DSPV security - Miner-Resistant Design of Lightweight Bitcoin Wallets

2019/03/21

What are lightweight wallets

Lightweight wallets are ones which are not full nodes. Lots of people use them because full nodes are costly: they cost time to setup/synchronize, education, disk space, bandwidth, RAM and a few other resources.

chris-belcher

Financial mathematics of JoinMarket fidelity bonds

13/7/2019

4/4/2021 (edited fixing formula and adding two graphs)

7/5/2021 (added appendix 1)

To read the context see the main document Design for improving joinmarket's resistance to sybil attacks using fidelity bonds.

chris-belcher

#! /usr/bin/python3

##this file calculates the success probability of a sybil attack on the
# orderbook with fidelity bonds used in joinmarket
# see https://gist.github.com/chris-belcher/87ebbcbb639686057a389acb9ab3e25b

from scipy.optimize import brentq
from time import time
from datetime import timedelta