How far away is a quantum computer that can break Bitcoin? In the second episode of The Quantum Bitcoin Podcast, Bitcoin historian Pete Rizzo and co-host Nathan Jeffay put the series' central question to Ethan Heilman, the Cloudflare researcher and Bitcoin cryptographer who co-authored BIP-360, the proposal that put quantum security on Bitcoin's agenda.
Episode two maps the threat itself: how Heilman went from dismissing quantum computers as science fiction to treating them as a this-decade problem, why he refuses to name a date, what the idea of Q-Day gets wrong, which parts of Bitcoin are actually exposed and which survive untouched, and why the NSA, the banks, and nearly half of web traffic have already gone post-quantum while Bitcoin debates. It closes with the warning signs to watch for, and why whoever breaks the cryptography first may choose to stay silent.
The Quantum Bitcoin Podcast is a series examining the quantum threat to Bitcoin, designed to be watched in sequence. Each episode opens with a discussion between the hosts, presents extended interviews with expert guests on a single key question, and closes with a recap of how the evidence has changed their thinking.
Presented in partnership with Starkware.
CHAPTERS
00:00 Cold open
01:00 What this episode covers
01:30 Rizzo and Nathan set up the question
05:49 Meet the expert: Ethan Heilman
06:16 From sci-fi to serious: how Heilman changed his mind
09:11 Why no one can give you a date
12:40 The state of quantum hardware in 2026
17:11 Q-Day: why there is no single moment
20:29 What post-quantum cryptography actually is
22:29 Why mining and SHA-256 survive
26:37 The real target: Bitcoin's signatures
29:46 Is there any science behind 2030?
31:22 Who has already migrated: the NSA, the banks, the web
33:22 Store now, break later
34:31 Why an attacker would listen, not steal
39:15 Choosing Bitcoin's post-quantum signatures
48:28 Tsunami warnings and the final signal
57:00 Recap: what we learned about the quantum timeline
GUESTS
Ethan Heilman is a researcher at Cloudflare and a Bitcoin developer and cryptographer whose work goes back to the earliest days of the project. He is the creator of TumbleBit and a co-author of BIP-360, the proposal that put post-quantum security on Bitcoin's development agenda.
FOLLOW
The Quantum Bitcoin Podcast: https://www.youtube.com/@QuantumBitcoinPodcast
Pete Rizzo: https://x.com/pete_rizzo_
Starkware: https://starkware.co/
Ethan Heilman: https://x.com/Ethan_Heilman
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