Quantum Computers Don't Exist w/ Brandon Black

In this episode, Rob and I sit down with Brandon Black (aka Rearden Code) for a deep dive into the quantum-computing debate around Bitcoin. We unpack why Brandon thinks the more useful framing is not “post-quantum” but “post-secp256k1,” and why Bitcoiners should care less about sci-fi narratives and more about understanding the actual cryptographic assumptions that protect coins today. Along the way, we revisit the now-legendary conference panel on quantum risk, talk through exposed pubkeys, xpub leakage, multisig, Taproot, Lightning force closes, and the difference between a theoretical break and an economically viable attack.

We also spend a lot of time sizing risk correctly. Brandon helps us separate slow, visible cryptographic degradation from the far less likely “everything breaks tomorrow” scenario, and we explore how incentives change depending on whether the attacker wants profit, strategic advantage, or chaos. The conversation eventually zooms all the way out to math, physics, and engineering: Shor’s algorithm may exist on paper, but building a machine that can actually matter for Bitcoin is still a very different question. If you want a rigorous, grounded conversation about quantum threats, elliptic curves, MuSig2, FROST, and how to think clearly instead of panicking, this is a great one.

The legendary panel:  https://www.youtube.com/watch?v=wbJkODcrz7Q

• Magic Internet Math: https://magicinternetmath.com/
• Brandon Black speaker profile: https://sv23.adoptingbitcoin.org/speakers/brandonblack/
• James O'Beirne: https://jameso.be/
• BIP 360: https://github.com/bitcoin/bips/blob/master/bip-0360.mediawiki
• BIP 327 (MuSig2): https://github.com/bitcoin/bips/blob/master/bip-0327.mediawiki
• BIP 340 (Schnorr Signatures for secp256k1): https://github.com/bitcoin/bips/blob/master/bip-0340.mediawiki
• BIP 341 (Taproot): https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki
• BIP 32 (Hierarchical Deterministic Wallets): https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki
• BIP 39 (Mnemonic code for generating deterministic keys): https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
• FROST Protocol (RFC 9591): https://www.rfc-editor.org/rfc/rfc9591.html