James Lovejoy on detecting and mitigating double-spends (EP.111)
On The Brink with Castle Island
Release Date: 08/10/2020
Walt Smith (Standard Crypto) on VC Investing in Bitcoin (EP.666)
On The Brink with Castle Island
Walt joins the podcast to discuss the current state of Bitcoin and what is investable in and around the Bitcoin ecosystem. In this episode: Austrian economics and Bitcoin Bitcoin's strengths and limitations when it comes to innovation and durability The modern role of decentralization and trust Whether nation-states will fully adopt BTC The role of Bitcoin in network states Owning BTC and other cryptoassets directly vs in equity wrappers Assessing the monetary value of cryptoassets BTC for payments?
info_outline
Weekly Roundup 09/12/25 (Hyperliquid stablecoin, CBOE continuous futures, stablecoin interest) (EP.665)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: We reminisce about the fork wars Figure goes public Gemini is slated to list The Winklevoss Quintenz drama rumbles on DAT updates CLARITY updates The fight over stablecoins paying interest continues Prediction markets and sports betting SwissBorg is hacked The CBOE is launching BTC and ETH “continuous futures” Harberger taxes
info_outline
Austin Federa (DoubleZero) on Building a Better Internet (EP.664)
On The Brink with Castle Island
Wyatt sits down with Austin Federa, the founder of DoubleZero to discuss the hardware systems that underlie blockchains and the internet. In this episode: Building a newer, better fiber network How and why much of internet hardware infrastructure is antiquated Why software innovation has taken precedent over hardware innovation Vertical integration and who has access to the best hardware systems Why hardware innovation requires startups and new entrants Why blockchains demand faster, reliable bandwidth Why a token framework offers a better incentive mechanism
info_outline
Weekly Roundup 09/05/25 (Stripe’s Tempo, NASDAQ tightens rules on DATs, WLF vs Sun) (EP.663)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: We review the US Open The Clippers scandal Fantasy football and the efficient market hypothesis Tax treatment of sports betting on Poly versus sports betting apps Are prediction markets more efficient than bookies? Galaxy launches a tokenized version of their stock NASDAQ is adding supervision rules for DATs Is it over for the DATs? World Liberty Fi launches and gets into a fight with Justin Sun Gemini files to go public Stripe releases details around their Tempo L1 Some academics have an explanation for why MSTR...
info_outline
Daniel Lev (Coinflow) on Stablecoin Payments (EP.662)
On The Brink with Castle Island
Wyatt sits down with , the founder of , to discuss the evolution of payments amidst a wave of stablecoin-enabled innovation. In this episode: Lurking legacy issues of payment networks How our current payment networks benefit end users but not merchants Types of merchant profiles and who stands to benefit Creating faster settlement Marketplace models and better rails How blockchain can reduce fraud and help businesses know their customers
info_outline
Weekly Roundup 08/29/25 (Stablecoins in CDMX, DAT issues, GDP on the blockchain) (EP.661)
On The Brink with Castle Island
Nic and Matt return for another week of news and deals. In this episode: Nic reviews the stablecoin conference in Mexico City Will the banks obsolete stablecoins? Some DATs are having trouble The government is putting GDP on the blockchain The CFTC opens the door to US customers trading on non-US exchanges Trump fires Lisa Cook Can the Fed be considered “independent” Google is developing a blockchain A BNB DAT gets delisted Tether is building on Bitcoin via RGB How does insider trading work in prediction markets?
info_outline
Sandy Kaul (Franklin Templeton) on Onchain Asset Management (EP.660)
On The Brink with Castle Island
Wyatt sits down with , head of digital assets at Franklin Templeton, to cover Sandy's work with the CFTC and DTCC and creating sandboxes for onchain financial markets. In this episode: How wallets stand to become the hub of asset management Lasting policy for crypto Protecting consumers in an open financial system
info_outline
Weekly Roundup 08/22/25 (SALT Jackson Hole, Wyoming Stable Token, Fed drama) (EP.659)
On The Brink with Castle Island
Matt and Nic are back with another week of news and deals. In this episode: Wyoming releases a stabletoken “FRNT” Matt’s bear encounter Bowman and Waller’s speeches at Jackson Hole Eric Trump’s Bitcoin prediction Is there an example of a DAT that makes sense? Should DATs trade at a persistent premium? Figure is going public Bullish goes public Is Saylor cornered? Quintenz’ nomination The DoJ decriminalizes writing open source code Is Polymarket cooked? Does a trial by a jury of your peers make sense? Content mentioned: Reducible Errors,
info_outline
Cupid & Hercules (Groom Lake) on Preventing and Responding to Cybercrime (EP.658)
On The Brink with Castle Island
Wyatt sits down with the founders of In this episode: How social engineering attacks are being used to exploit companies in crypto and beyond How companies can better protect themselves and be vigilant of these exploit attempts The future of cybersecurity software for crypto
info_outline
Luke Xie (SatLayer) on The Next Generation of Bitcoin Yield (EP.657)
On The Brink with Castle Island
Wyatt sits down with , cofounder of for a conversation about Bitcoin yield. In this episode: What makes financial markets for BTC unique How BTC DeFi will evolve, in the backdrop of the broader macro environment DeFi vs CeFi financial systems for BTC
info_outlineJames Lovejoy, recent MEng MIT grad and former graduate researcher at the MIT Digital Currency Initiative, joins the show to talk about his masters thesis and associated project focusing on detecting double-spends in proof of work cryptocurrencies. Previously, little data was collected in a systematic way to detect double-spends and reorganizations across many cryptocurrencies. James' project sheds light on previously unknown security properties of PoW. In this episode:
- How James came to work on Vertcoin
- Why James thinks ASIC resistance is valuable
- James' blockchain monitoring project and why it matters
- Why reorgs are challenging to detect
- Why investigating the economic damage of reorgs is difficult
- How James noticed a 51% attack in progress on Vertcoin and intervened to save Bittrex money – and how this can be replicated
- Why understanding Nicehash is critical to detecting and dealing with 51% attacks
- James' critiques of dominant theoretical models of PoW security
- How James found reorgs and counterattacks happening on BTG in real time
- Why exchange processes like KYC might actually help protect blockchains from reorgs
- How permissionless trading and leverage makes certain blockchains more vulnerable to attacks
- Rules of thumb for confirmation requirements for exchanges
- The issue with calling coins "Nicehash-able" – and why it's likely a lowball
- How exchanges can proactively mitigate the risk of 51% attacks and what they should be targeting
- How BTG developers finally defeated deep reorgs
- Whether James is confident in the long-term prospects of PoW
- Whether James still believes in GPU mining
Content referenced in this episode
- James Lovejoy, An Empirical Analysis of Chain Reorganizations and Double-Spend Attacks on Proof-of-Work Cryptocurrencies
- Raphael Auer, Beyond the doomsday economics of “proof-of work” in cryptocurrencies
- Eric Budish, The Economic Limits of Bitcoin and the Blockchain
- Hasu, Prestwich, and Curtis, A model for Bitcoin's security and the declining block subsidy
- Carlsten, Kalodner, Narayanan, Weinberg, On the Instability of Bitcoin Without the Block Reward
- Moroz, Aronoff, Narula, Parkes, Double-Spend Counterattacks: Threat of Retaliation in Proof-of-Work Systems
- Judmayer et al, Pay-To-Win: Cheap, Crowdfundable, Cross-chain Incentive Manipulation Attacks on Cryptocurrencies
- Liao and Katz, Incentivizing Blockchain Forks via Whale Transactions
- James Lovejoy and David Vorick, ASICs and cryptocurrencies: benefits and drawbacks [debate]
- Nic Carter, It's the settlement assurances, stupid [blog]
- Elaine Ou, Cryptocurrency Deals can Always be Erased, for a Price [article]