Bitcoin Rails | Isabel Foxen Duke

“You can get security in two ways in this world: through power or through privacy.” Obi Nwosu, co-founder of Fedi - the largest application layer built on top of e-cash protocol Fedimint - joins me on the show to discuss its role in protecting what he argues is the single most important feature of digital money: Privacy. Self-custody alone, he argues, “is not enough” for protection against attacks...

“99% of Bitcoin is held idle, not because of lack of interest, but because of lack of trust.” Not long after Ordinals (and BRC20) revitalized the “Bitcoin DeFi” narrative, Babylon Labs seemingly leapt onto the scene with what felt like overnight success – locking several billion dollars of TVL in its “trustless Bitcoin staking” protocol. With some of the most interesting advisors and contributors...

Matt Hill, CEO of Start9 — which is, as of this recording, the largest distributor of retail Bitcoin nodes (aka “pleb nodes”) — joins me to unpack the biggest underlying question of 2025: Who really holds power in enforcing (or disincentivizing) storage of arbitrary data on Bitcoin? Unsurprisingly, Start9 has seen an epic leap in sales with the popularization of Knots as more and more “plebs” are...

It was about four years ago that Facebook’s famous effort at creating its own cryptocurrency and crypto-native payments system (Libra, then Diem) was effectively halted by an unending stream of regulatory scrutiny and compliance blocks. Some leaders of the project went on to create crypto-projects of their own (e.g. SUI and Aptos), however, “Head of Facebook Financial” @davidmarcus, along with Die...

A couple months ago, I co-hosted an X space with Layer Two Labs re: “Should Bitcoiners care about quantum computing?” You can imagine our surprise when (in?)famous tech investor Martin Shkreli arrived to share that he’s been researching this very question for years… and dropped that he’s been personally considering raising funds to hire a team of mathematicians to hack Satoshi’s Coins. In this epi...

Programmable BRC20 tokens, dubbed “BRC2.0,” launched a few short weeks ago after more than a year of building and anticipation. This effort was spearheaded by BRC20 lead-maintainer team Best In Slot, who joined the BRC20 core team after their development of open source Ordinals indexer “OPI,” and solidifying their title as a leading Ordinals infrastructure provider. In this episode, I sat down wit...

As interest in Bitcoin Layer 2s skyrockets, the inclusion of OP_CAT — an opcode enabling concatenation of elements in the Bitcoin stack — has become a key technical upgrade to watch for its potential in the development of trustless bridges. OP_CAT co-author @ethan_Heilman and I sat down to discuss debate around this opcode — including why it’s controversial, the cultural environment shaping its fu...

Co-creator of the Lightning Network, inventor of DLCs, and author of Utreexo—Tadge Dryja is easily one of the most influential developers in Bitcoin’s history. After co-authoring the Lightning Network paper in 2015—leading to the development of what is still easily the most well funded and widely adopted Bitcoin L2 in the world—Tadge continued with some of the most influential Bitcoin research in...

“Most people don’t think about security until it’s too late,” says the Casa co-founder and CSO. One of the most prolific thought-leaders in Bitcoin security and privacy, there are few people who understand the nuances of Bitcoin security quite as deeply - not to mention the OPSEC practices required to protect against wrench attacks, for instance, which are rising globally as Bitcoin price increase...

We love gleefully controversial figures on this show—and Paul Sztorc is no exception. One of the most outspoken and alternative thinkers in Bitcoin, Paul proposed BIP300/301—a softfork mechanizing the creation and removal of trustless Bitcoin sidechains, aka “Drivechains,” in late 2022. While the proposal received diverse reception from prominent Bitcoiners “across the aisle,” it’s clear that acti...

There are few people on the planet more deeply entrenched in ‘Bitcoin Art’ than Rare Scrilla - and few people more influential in its culture and adoption. A key figure in "Rare Pepe" culture, Scrilla pioneered the "Fake Rares" movement, igniting a significant surge in demand for Counterparty assets in late 2021 - nearly eight years after he began recording Bitcoin-inspired hip-hop, influenced by...

The Bitcoin Historian Pete Rizzo has been chronicling Bitcoin longer than almost anyone. Former editor at CoinDesk and Bitcoin Magazine (and more recently the Bitcoin anchor Blockworks), Pete seems to be close to the helm of *the* top crypto media publication at any given time. ------------------------------------------------------------------- In this episode of Bitcoin Rails, Pete and I sit down...

Fred Krueger has always “followed the money” from Finance in the 80s, to software in the 90s, to the internet in 00s… and finally, to Bitcoin. A self-described “opportunist,” it was the networks-effects argument that ultimately set Fred on a heavy Bitcoin-focused path—and more recently opened his eyes to the possibility that “fast chains” too will disrupt the fiat system permanently. In this episo...

After starting full-time in Bitcoin straight out of college (as a co-founder of Blockstream… NBD) Matt Corallo is one of the most long-standing and prolific Bitcoin contributors in the world, having worked on several of its most influential projects—including Lightning, Stratum V2, the original sidechains paper, and more. That being said, he’s arguably best-known in recent history for sounding the...

One of the most influential voices in “Bitcoin Season II,” Udi Wertheimer is one of the most controversial and, perhaps, most misunderstood figures in the Bitcoin community broadly. A self-identified “survivor” of Bitcoin maximalism, Udi’s critiques of Bitcoin-only tribalism – and the suppression of nuanced discussion that arises as a result – made him the perfect spokesperson for post-Ordinals Bi...

BITCOIN RAILS EPISODE #27: Building Rollups on Bitcoin + the Battle for ‘OP_Return’ | with @citrea_xyz founders @0x_orkun and @ekrembal_ The founders of Citrea were unlikely superstars in the Bitcoin ecosystem—a team of 24-year-olds, barely out of school, with most of their prior experience in the Ethereum ecosystem. Yet they have rapidly emerged as one of the leading teams at the forefront of Bit...

The introduction of covenants to Bitcoin has been a long-standing debate—one recently brought back into consideration with the memetically-driven advocacy of “OP_CAT” by the Taproot Wizards. In previous history, the most likely contender for a covenants-enabling OP code was “CTV” (check template verify)—a simpler and more narrow way to enable covenants—that, while once considered radical, is now s...

In early 2024, independent developer Robin Linus published a paper outlining how one theoretically could verify zero-knowledge proofs on native Bitcoin for near-trustless scaling. A feat long considered impossible without a soft fork—the paper went viral, amassing over 3 million views and “nerd-sniping” some of the brightest developers and investors in the space. Since then, a flood of builder eff...

The History of Zero-Knowledge Proofs | with ZK “Godfather” Eli Ben Sasson In 2013, computer science professor Eli Ben-Sasson presented his research on zero-knowledge proofs at a small Bitcoin conference outside of Standford University. The presentation immediately sparked interest from Bitcoin Core developer Greg Maxwell—leading Eli into over a decade of sustained work advancing ZK-based solutions...

Edan Yago has been in the “Bitcoin DeFi” ecosystem since before that term was a thing. An early adopter of Rootstock, Yago developed the “largest DeFi ecosystem in Bitcoin” through DEX @sovryn before becoming obsessed with Zero Knowledge Proofs and the promise of BitVM for enabling more trustless rails into and out of Bitcoin. While Yago has most recently been working on the modular-style BitVM br...

Michael Casey was brought on by MARA to address an often overlooked problem in the world of Bitcoin Layer 2s… they generally don’t contribute much to the security budget of Layer 1 Bitcoin. We often hear concerns about fees being either too high OR too low depending on how you look at it… too high if you’re optimizing for 8 billion people being able to use the network in a self-custodial way—but t...

Stacks was one of the first “Bitcoin L2s” (or “Bitcoin scalers” if you’ll call it that) that has stayed incredibly relevant in the Bitcoin Season 2 era. From conducting the first regulated token sale to becoming a face of the Ordinals ecosystem, Trustmachines COO Rena Shah guides us through the network’s history, and why she believes its positioned to keep both Bitcoin’s network and ethos alive. I...

If you’re following Ordinals, you’ve likely heard the term “OP_CAT,” a proposed Bitcoin opcode popularized by the Taproot Wizards In this episode, I brought on Janusz and Red from Bitcoin Layers to break down what OPCAT is, how it works, and what it makes possible for Bitcoin—hint hint: you’re gonna learn all about ‘covenants’ and their role in trustless bridging in this episode. Of course, this i...

Is Bitcoin going to break? Don’t roll your eyes: quantum computing may be a more realistic threat to Bitcoin than you think, and it may only be a few years away. Thankfully, Bitcoin dev Hunter Beast is preparing us in advance with the thoughtful BIP 360 – an effort to bring post quantum cryptography to Bitcoin. In this episode, we discussed:- How quantum computing threatens your Bitcoin wallet- Th...

Build on Bitcoin (BOB) co-founder Alexei Zamayatin is older than he looks folks: he’s been researching how to build “trustless” Bitcoin bridge architecture since 2018, long before it felt anything close to a mainstream conversation. When Robin Linus came out with BitVM, he believed he found the answer to this impossible problem, and has since poured his efforts into BitVM2 and BOB – a “hybrid L2”...