Dan @bitgould

Essays & articles

Privacy sans Mixing, Interactive Payment Batching is Better
A description of payjoin as batched transfer settlement infrastructure. I go into how it helps prepare for the next wave of blockspace scarcity while beating blockchain spies' most common tools as a bonus.
Privacy sans Mixing, Tracking Growth in Payjoin Adoption
Documenting payjoin adoption since its introduction in 2018.
Privacy sans Mixing, What Does Privacy Mean
Reckoning Satoshi's writing with bitcoin privacy discourse.
Privacy sans Mixing, Now Accepting Payjoin
On the launch of payjoin.org.
Chaincase, Payjoin Design Flow
A reflection on the first attempt at the private payments bitcoin design challenge.
Chaincase, Interactive Transactions with PSBT
A history of the evolution of Partially Signed Bitcoin Transactions.
Bitcoin Magazine, Using Taproot And FROST To Improve Bitcoin Privacy
My account of a week long threshold signature hackathon for Fedimint. I recount how the team of four of us integrated FROST with Fedimint and how that reduces transaction fees, improves scalability, and increases security.
Chaincase, Lightning Powered Payjoin
Increasing lightning channel funding throughput and privacy with payjoin.
Chaincase, What do you mean 👋 Unlink Bitcoin 👋
Explaining how modern bitcoin privacy quantification falls short and the direction I propose to find better privacy metrics.
dangould.dev, The Ben-Or, Goldwasser, and Widgerson SFE Protocol
Lecture notes I scribed covering BGW Secure multi-party computation during Boston University CAS CS 548 Advanced Cryptography instructed by Ran Canetti on January 29, 2019.
dangould.dev, Multisignature Bitcoin in C#
A walkthrough build of a script multisig wallet in C# using NBitcoin. I gave this workshop at Boston Hacks.
dangould.dev, Tal Rabin: 51% Attacks are Hard
I explain a common misunderstanding of 51% attacks repeated by world class cryptographers at RSA Conference 2019.

Papers I have contributed to

Bitcoin Design Guide, The Payjoin Experience
Yashraj
This case study outlines the incentives and objectives for both senders & receivers, Analyses the payjoin UX on both sides and proposes approaches to design payjoin experiences, [and] proposes specific user flows and, where possible, working designs for the same.
WabiSabi: Centrally Coordinated Coinjoins with Variable Amounts
Ádám Ficsór, Yuval Kogman, Lucas Ontivero, and István András Seres
Bitcoin transfers value on a public ledger of transactions anyone can verify. Coin ownership is defined in terms of public keys. Despite potential use for private transfers, research has shown that users' activity can often be traced in practice. Businesses have been built on dragnet surveillance of Bitcoin users because of this lack of strong privacy, which harms its fungibility, a basic property of functional money. Although the public nature of this design lacks strong guarantees for privacy, it does not rule it out. A number of methods have been proposed to strengthen privacy. Among these is CoinJoin, an approach based on multiparty transactions that can introduce ambiguity and break common assumptions that underlie heuristics used for deanonymization. Existing implementations of CoinJoin have several limitations which may partly explain the lack of their widespread adoption. This work introduces WabiSabi 1 , a new protocol for centrally coordinated CoinJoin implementations utilizing keyed verification anonymous credentials and homomorphic value commitments. This improves earlier approaches which utilize blind signatures in both privacy and flexibility, enabling novel use cases and reduced overhead.
See my contributions on GitHub.
BU JD 792 National Security and Technology: Law and Policy, Cutting through the Click Wrap: A New Framework for Optimal Software Vendor Liability
Jacob M. Berman and Daniel Gould
A software liability framework based on the essential freedoms of software to better manage risks of proprietary software vulnerabilities and promote the proliferation of free and open source software. Copies available upon request.
Despite the enormous growth in the value of the United States software industry in the past twenty years, and the tremendous potential for economic loss associated with the exploitation of software vulnerabilities, vendor liability for reckless software vulnerabilities remains a critically underdeveloped field of law.
…
To combat these issues this article proposes an optimal standard of liability for insecure software, which will encourage proprietors to undertake a higher standard of care without imposing greater burdens on innovation than the value of the harms it prevents. The optimal standard will also promote national security by incentivizing developers to create secure software without chilling innovation. Thus, the article recommends that the United States should adopt a federal statute that imposes liability on proprietors that recklessly, knowingly, or intentionally sell, administer, or distribute insecure software.

Podcast appearances

Stephan Livera Podcast, SLP576 Payjoin Dev Kit for Bitcoin Privacy – Dan Gould
I join Stephan to discuss how Bitcoin privacy could be improved with more PayJoin adoption. What’s more, it might also benefit users in consolidating their wallets or potentially even fee savings. We discuss how this could be integrated into more bitcoin wallets.
- What is a PayJoin?
- How it helps privacy
- Other benefits in efficiency
- Downsides and trade offs
- Changes with the v2 PayJoin protocol
- PayJoin Directory
- Payjoin Dev Kit
Tokyo Citael Builders, Interview with Dan Gould
- Incentives to get effective bitcoin privacy
- Tradde offs and incentives in different modes of communication
- East Asia vs USA as citael locations
Tom & Jerry 發現比特幣, EPI 58 : Payjoin 比特币隐私协议【Dan Gloud】
- 被比特自由貨幣性質所吸引
- Edward Snowden關鍵事件啟發專注比特幣隱私發展
- 以比特幣研發者獲得資助金
- 學習用中文聊比特幣
- 超比特幣化的想法
Pleb UnderGround, Here's How PayJoin Is Solving Bitcoins Privacy Problem! | Guest: Dan Gould | EP 63
BTC Sessions, WHY ARE WE BULLISH? Dan Gould, Lawrence Lepard, Dom Bei Bitcoin - Uncovering Their Bullish Insights
TFTC Podcast, 431: Bitcoin Privacy and the Payjoin Dev Kit with Dan Gould
Marty created a Payjoin Dev Kit FAQ by asking open questions on air. "Dan Gould is a bitcoin developer who is hyper-focused on improving the ability of individuals to transact using bitcoin with better privacy assurances. Recently he launched the Payjoin Development Kit, which aims to make it easy for developers building bitcoin wallets and exchanges to implement Payjoin, which is a way of creating and executing a transaction in a way that perturbs common-input ownership heuristics used by chain surveillance companies to follow people through bitcoin's ledger as they transact. Dan gives a detailed explanation of how PDK works, why it exists, and what it can do for bitcoiners."
Conor Chepnik Podcast, Payjoin🟠🔀
Conor and I sit in person in Boston to share a pleb perspective on Payjoin. We cover Bitcoin privacy basics, what it would take to make adoption standard, incentives to make that happen, and whether some of the cultlike elements of Bitcoin internet culture make it a religion or not. This one was a lot of fun where I get to share more personal values and elicit them from Conor instead of going into technical details.
MineYourBiz, #Bitcoin does NOT include #Privacy - Can PayJoin Improve It?
Where I answer privacy focused Payjoin questions for a wide audience of cryptocurrency enthusiasts. The title's a bit of bait, Bitcoin is pseudonymous by default, of course.
Bitcoin Optech, Bitcoin Optech Newsletter #251 Recap Podcast
Testing HTLC endorsement, standard specifications for LSPs, Challenges with zero-conf channels when dual funding, Advanced payjoin applications, and more. Special guests include @glozow, @actuallyCarlaKC, Severin Bühler and myself.
BOB Radio, Bitcoin Privacy Tools and Practices with Gandlaf21, Dan Gould & Giacomo Zucco
BOB Radio invited me to speak on Bitcoin Privacy Tools and Practices with Gandlaf21 and Giacomo Zucco. Giacomo listed the three main levels of privacy to concern yourself with, and we broke down how to address each one, aiming past controversy to deliver actionable advice.
Global Bitcoin Fest, Meet the Taiwan Bitcoin Community
A marathon twitter spaces in which we dive into the culture of Taiwan and the history of the bitcoin scene there.
Bitcoin Optech, Bitcoin Optech Newsletter #236 Recap Podcast
I cover the Serverless Payjoin proposal to maintain the security of BIP78 payjoin without the server requirement. Bastien Teinturier discusses a method for sending async payments that provide the spender with proof they paid the receiver.
Join the Wasabikas, Chaincase: Next Generation Bitcoin CoinJoin on iOS Mobile
My first ever podcast appearance. Thanks to Max for taking the chance way back.