S17 E22: Jeremy Rubin on CTV, Char & Building on Bitcoin

Jeremy Rubin is the author of BIP 119 (OP_CTV, Check Template Verify) and co-author of BIP 348 (CSFS, Check Sig From Stack). More recently, he started working on Char: a decentralized shared sequencer for Bitcoin layer 2s.

In this episode, which we recorded at the LayerTwo Labs booth during the Bitcoin 2026 conference in Las Vegas, we talk about the challenges involved in improving Bitcoin and why Jeremy chooses to be a relentless builder even in an adversarial environment.

Time stamps:

00:00:48 Podcast Introduction and Sponsors

00:03:02 Jeremy Rubin's Bitcoin Journey

00:03:24 Introduction to Check Template Verify (CTV)

00:04:44 The Philosophy Behind CTV

00:06:40 CTV for Congestion Control

00:07:57 CTV for Self-Custody Vaults

00:09:35 The Failed Activation of CTV

00:11:25 The "Technical Consensus" Debate

00:13:45 FUD and Misinformation Campaign

00:17:45 Blockstream's Role in Bitcoin Development

00:21:44 The Inevitability of CTV

00:26:04 The State of the Bitcoin Ecosystem

00:28:20 Bitcoin Maximalism and Cypherpunk Spirit

00:29:34 Learning from Other Projects

00:31:52 Bitcoin Cash's Technical Progress

00:35:39 The "Small Blocker" Paradox

00:37:34 Cultural Barriers to Building

00:39:24 The Future of Bitcoin and Freedom

00:43:08 Paul Sztorc's Ecash Fork

00:49:06 Confiscating Satoshi's Coins

00:58:51 The Problem with OP_CAT

01:01:56 Security Practices at Conferences

01:06:01 What Excites Jeremy About Bitcoin Today

01:09:01 On Being a "Difficult" Personality

01:12:20 Introduction to Char

01:15:04 Why Use Proof of Stake?

01:18:38 Final Thoughts on Agency and Freedom