Post-Quantum Bitcoin Signatures (+ their tradeoffs) | ETHAN HEILMAN & JONAS NICK

According to BIP 360 co-author, Ethan Heilman, Bitcoin needs a minimum of two soft forks to become quantum resistant: P2MR (or an output type that can safely execute PQ signatures) + a post-quantum checksig (signature scheme).

Ethan and the BIP 360 team (including myself and Hunter Beast) introduced the P2MR part via a BIP 360 update late last year—but the question remains, what’s the most appropriate PQ signature scheme for Bitcoin?

They all have substantive tradeoffs, but hash-based signatures seem to be leading technical discourse—likely due to recent optimizations by Jonas Nick and the broader Blockstream⁩ research team.

It was an honor to sit down with both of these men - arguably the two most influential and productive cryptographers in Bitcoin quantum mitigation right now - for an in-depth review of the leading PQ signature schemes and a temperature check on Bitcoin’s post-quantum planning process.

TBH, if you want to skip the noise and jump straight to the signal on quantum, this is the interview to watch.

In this episode, we discuss:

• What needs to happen at the soft fork, infra and mitigation levels to fully quantum-harden Bitcoin
• Recent updates to BIP 360 + breakdown of the leading hash-based signatures schemes for Bitcoin (SHRINCS + SHRIMPS)
• Why we may actually get consensus around a stateful scheme for Bitcoin
• Comparisons of hash-based signatures vs Lattice and Isogeny-based schemes
• Assessing the risks of both waiting too long, and acting too fast (and why quantum is a better threat to be facing than a potential classical attack)

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