James Lovejoy on detecting and mitigating double-spends (EP.111)
On The Brink with Castle Island
Release Date: 08/10/2020
Weekly Roundup 09/11/26 (Liquid hack, AI x-risk, Silvergate revisited, can AI leak MNPI?) (EP.739)
On The Brink with Castle Island
Matt and Nic are back for more deals and news. In this episode: We bring back his the theme music Anthropic employees think there’s a 10% chance AI destroys humanity Was Jacob Coxon astroturfed or real? Are Anthropic employees being sincere or cynical? Blockstream’s Liquid sidechain is hacked What does the Liquid hack mean for privacy coins? Hunter Biden launches the $LAPTOP memecoin IONQ says they will be able to crack ECC in two years Ex Silvergate CEO Alan Lane speaks out OpenAI offers a solution to the Navier-Stokes problem Can insider information leak through AI...
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Weekly Roundup 09/04/26 (HuggingFace hack breaks containment, Hyperliquid onshoring, RSA260 factored, is the stablecoin sandwich cheaper?) (EP.738)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: We determine the winner of the bad boys theme song competition Dwarkesh ignites controversy with his OpenAI hack recap What actually happened with OpenAI and Huggingface? Gwern’s and Matt Huang’s short story competition Will AI make us dumb? 200m Americans KYC data has been hacked Prediction markets lawsuit heading to SCOTUS? Robinhood Chain is taking off Strategy is buying Bitcoin again Should Members of Congress be paid more? Cronos suffers a defi hack Revolut gets a bank charter Is the stablecoin sandwich...
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Guy Young (Ethena) on Digital Financial Markets (EP.737)
On The Brink with Castle Island
Wyatt sits down with Guy Young, founder of Ethena, for Guy's third appearance on the pod. In this episode: What has driven Ethena's success and durability? Where is there demand for other yield assets? Where is capital coming from? Is full onchain portfolio construction possible today? Why tokenize financial products at all? Who are the eventual winners? How is Ethena positioning to an evolving onchain yield landscape?
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Weekly Roundup 08/28/26 (BankChain alliance, Goat grazing hedges, SHRINCS, is maximalism over?) (EP.736)
On The Brink with Castle Island
Matt and Nic return for another week of deals and news. In this episode: Matt and Nic consider candidates for the new bad boys intro music 39 state banking associations form the BankChain alliance Blockstream researchers proposed SHRINCS, a PQ signature scheme for Bitcoin How much should depositors care about bank credit risk? Kalshi hosts a prediction market on goat grazing regulation Are trading bot agents getting good? Blockstream proposes SHRINCS for Bitcoin Zcash hits an 8-year high Treasury designates anyone helping Iran’s crypto sector AI watermarking Bad boys theme song...
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Weekly Roundup 08/21/26 (SALT Wyoming, SEC’s Reg Crypto, Tether’s big 4 audit, Crypto Privateers) (EP.735)
On The Brink with Castle Island
Matt and Nic return for another week of news and deals. In this episode: The boys review SALT Wyoming in Jackson Hole Why did Stripe buy Openrouter? Stripe says we have entered the Singularity People are upset about data centers The SEC proposes Reg Crypto governing token issuance The CFTC convenes a crypto roundtable in Washington FASB proposes treating stablecoins as cash equivalent under GAAP World Liberty gets an OCC charter Trump should divest his WLF tokens to push Clarity through Saylor wriggles out of another jam Tether passes a big 4 audit The White House issues a “crypto...
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Weekly Roundup 08/14/26 (Anti-Datacenter sentiment, dinosaur fossil investing, SEC is DIYing Clarity) (EP.734)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: Who is the main character in AI? Why are people so mad about datacenters? Sherrod Brown is back and he’s running against AI Are datacenters being built with Flock? Culturally scarce goods and dinosaurs are rallying The SEC starts to fill the gap left by the Clarity Act FinCEN ends beneficial ownership reporting The CFTC charges a $400m Ponzi operator Are there successful Ponzi schemers? Is Bitcoin at risk from miners transitioning to AI? The collapse of the diamond market
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Weekly Roundup 08/07/26 (Coldcard hack continues, Ethereum mulls an issuance tweak, ai16z winds down, Clarity deadline looms) (EP.733)
On The Brink with Castle Island
Matt and Nic are back with more news and deals. In this episode: Why the Coldcard hack is worse than some major exchange and DeFi hacks What the Coldcard hack told us about the need for open weight models Is self custody over? MSTR sells more Bitcoin An FBI agent steals $1m in crypto NY state sues Kalshi Ethereum considers another change to issuance Ethereum needs to resist the urge to change monetary policy ai16z’s Eliza winds down the merit of reading sci fi The cofounder of Sui leaves for Anthropic Will Anthropic keep the discoveries to themselves? The WSJ gets it wrong on Clarity ...
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Weekly Roundup 07/31/26 (Situational Awareness collapse, Coldcard exploit, latest on CLARITY, Visions of Bitcoin 8 years on) (EP.732)
On The Brink with Castle Island
Matt and Nic are back for another week of news and deals. In this episode: What the novel Hyperion tells us about AI doom Situational Awareness liquidates most of its public book after a sharp AI selloff Will Leo have a second act? Why has AI been selling off? Over 1000 BTC stored in Coldcard wallets were stolen due to bad entropy Where does self-custody go from here? What happened with Coldcard? Political winds are shifting against crypto as midterms loom Strategy continues to strengthen its balance sheet with MSTR common sales An ice cream shop in CA is hedging the weather with Kalshi...
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Weekly Roundup 07/24/26 (BTC Security Consortium, Genesis’ Terra trade, DAT departures, Farewell to BitMEX, Network State drama) (EP.731)
On The Brink with Castle Island
Nic and Matt are back for another week of news and deals. In this episode: The Fat Model Thesis Are OAI and Anthropic in real trouble with Kimi? The Bitcoin Security Consortium is announced to tackle quantum risk Galaxy announces their Quantum Readiness Initiative Clarity is beleaguered in Washington Polymarket and Kalshi keep feuding The SEC settles with Coinbase over Gensler’s lost text messages We uncover some new documents revealing that Genesis inadvertently kicked off the UST depeg Jack Mallers leaves the XXI Capital DAT Movement Labs declares bankruptcy BitMEX finally winds...
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Weekly Roundup 07/17/26 (Teleprompter insider trading, the AI DeFi apocalypse fizzles, NY’s datacenter ban) (EP.730)
On The Brink with Castle Island
Matt and Nic are back with the deals and news of the week. In this episode: Nic licks his World Cup wounds Do Bitcoin Treasury strategies make sense? Trying to make sense of Saylor’s “bitcoin rating” Trump’s teleprompter operator has been trading on what Trump is going to say in his speeches Why do people keep insider trading on prediction markets? Clarity Act odds are trickling down Strategy shores up their balance sheet Is the Bitcoin cycle finally turning? Stripe bids for Paypal The AI DeFi apocalypse didn’t happen Kathy Hochul’s AI datacenter moratorium Why is Anthropic...
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]