James Lovejoy on detecting and mitigating double-spends (EP.111)
On The Brink with Castle Island
Release Date: 08/10/2020
Bernardo Bilotta (Stables Money) on Stablecoin Fintech in APAC (EP.640)
On The Brink with Castle Island
Wyatt sits down with , founder of In this episode: Stablecoin usage in APAC, for saving, spending, and beyond Retail adoption that bleeds into institutional adoption The forward-looking path for stablecoin finance
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Weekly Roundup 06/27/25 (Bitcoin for mortages, Fiserv adopts stables, Fed drops reputation risk) (EP.639)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: Golden age of prediction markets NYC mayor’s election What’s happening with Canton? The FHFA says crypto can be a qualifying asset for mortages Our thoughts on the market structure bill The significance of the Fiserv stablecoin pilot $500m public access vehicle for BNB The Fed drops reputational risk in bank supervision EO for debanking is rumored Kraken HQ is moving to Wyoming Texas buys Bitcoin Will banking hours be obsolete?
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Josh Frank (The Tie) on Crypto Market Intelligence (EP.638)
On The Brink with Castle Island
, the founder and CEO of joins the show. In this episode we discuss: The origin story behind The Tie and how Josh approached founding the business. The digital asset data market. How sentiment data has evolved in the digital asset industry. The buy-side landscape for digital assets and how Josh sees that evolving in the coming years. The Canton Network and how The Tie is working with this new protocol. To learn more about The Tie visit their .
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Luca Prosperi (M0) on a Universal Stablecoin Platform (EP.637)
On The Brink with Castle Island
Ria sits down with , CEO and Co-Founder of , a universal stablecoin platform that enables customization while preserving interoperability across assets. In this episode, we cover: Lessons from MakerDAO Drawing inspiration from the dual banking system Building a base asset that is decentralized, permissionless and ossified Issuing opinionated assets via wrapping and extensions while maintaining interoperability
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Weekly Roundup 06/20/25 (GENIUS passes, Nobitex Hack, FUD dice retrospective) (EP.636)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: The GENIUS Act passes the Senate Should GENIUS be stapled to market structure? Bessent thinks stablecoins could be $3.7T by 2030 Stablecoin FUD Will stablecoins destabilize the US Treasury market JPM's stablecoin FUDs JPMD's deposit token will launch on Base The future of stablecoin yield in the US Circle hits a $50b market cap Yellowcard partners with Visa in Africa Kraken will launch a token for their Ink L2 Are Walmart and Amazon looking at their own stablecoins? An Iranian crypto exchange is...
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Santi Alvarado (XFX) on Improving FX for Stablecoins (EP.635)
On The Brink with Castle Island
Sean is joined by Santi Alvarado, CEO/Co-Founder of , to cover their seed raise and how money moves cross border. In this episode: Background of Santi and how he made his way into crypto How legacy FX settlement operates today How XFX enables more liquidity for cross border payment companies
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Greg Genega (KPMG) on Crypto Auditing (EP.634)
On The Brink with Castle Island
Wyatt is joined by , Digital Asset and Blockchain leader at KPMG, for a conversation on the state of crypto auditing. In this episode: How KPMG works with crypto companies and protocols Relevant new innovations in the crypto space What to look out for as a new founder
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Weekly Roundup 06/13/25 (Stripe buys Privy, Stablecoin FUD, Rogue Traders) (EP.633)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: Stripe acquires wallet infrastructure company Privy for an undisclosed sum Fireblocks’ stablecoin data Stablecoin FUD Were mnemonic phrases a local maxima? Bullish and Gemini have filed preliminary paperwork for IPOs Soc Gen is launching a USD stablecoin We look at some infamous rogue traders Gamestop’s bitcoin strategy is a flop DTCC is looking at issuing a stablecoin
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Weekly Roundup 06/06/25 (Circle IPO, Singapore rules, Trump wallet?) (EP.632)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: Circle goes public and has an explosive first day The IPO window is open Circle’s vision for CPN is launching a token Will cannibalize Solana? JPM will let clients use Bitcoin ETFs as collateral Strategy introduces new offerings Magic Eden’s strange Trump wallet app announcement Truth Social Bitcoin ETF A K Pop Bitcoin access vehicle Korea’s cultural renaissance Singapore’s abrupt change in posture
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Isha Varshney (Celo) on Stablecoin Adoption Across Markets (EP.631)
On The Brink with Castle Island
Wyatt sits down with from the to talk stablecoins. Covered in this episode: Payments in Kenya and Sub-Saharan Africa Stablecoin usage and USDT The future of non-stable tokens
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]