I keep a diary of all the work I do on bitcoin privacy.
It may also be interesting to my collaborators and donors, and anyone who wants to follow how my projects are going (these days I'm almost exclusively working on developing CoinSwap, see https://gist.github.com/chris-belcher/9144bd57a91c194e332fb5ca371d0964).
Support this work with a donation: https://bitcoinprivacy.me/coinswap-donations
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.
list of links for quick copypasting when debating on forums, also useful as a reading list
this was posted on reddit, link is https://www.reddit.com/r/Bitcoin/comments/7mh8c2/long_live_decentralized_bitcoin_a_reading_list/
some of these links may be subject to linkrot, try looking on archive.org or archive.is
a trip to the moon requires a rocket with multiple stages by gmaxwell https://www.reddit.com/r/Bitcoin/comments/438hx0/a_trip_to_the_moon_requires_a_rocket_with/
JoinMarket has a problem where it assumes different nicknames have different bitcoin wallets. This can be exploited by people running multiple yield generator bots from the same wallet, so they get a higher rate of profit at the expense of de-legitimizing the system for privacy.
A merkle tree is a way of producing a commitment to a set, which can later can prove that elements are contained within the set using only O(logN) data, and only revealing one other element in the set.
For example here is a merkle tree commiting to a set of numbers {6, 3, 9, 0, 8, 4, 7, 2}
25/5/2020
Imagine a future where a user Alice has bitcoins and wants to send them with maximal privacy, so she creates a special kind of transaction. For anyone looking at the blockchain her transaction appears completely normal with her coins seemingly going from address A to address B. But in reality her coins end up in address Z which is entirely unconnected to either A or B.
Now imagine another user, Carol, who isn't too bothered by privacy and sends her bitcoin using a regular wallet which exists today. But because Carol's transaction looks exactly the same as Alice's, anybody analyzing the blockchain must now deal with the possibility that Carol's transaction actually sent her coins to a totally unconnected address. So Carol's privacy is improved even though she didn't change her behaviour, and perhaps had never even heard of this software.