New Version of BIP 360 Just Hit The Mailing List

Hello everyone!

I’m excited to share that the BIP 360 team has completed a major update, reflecting months of work to make the proposal clearer, more readable, and more accessible to the entire Bitcoin community.

We have been working on a clean rewrite of the BIP, led by our new coauthor Isabel Foxen Duke. Our goal was to present the proposal’s motivation, rationale, and technical details in a way that is readable by developers, cryptographers, and non-technical bitcoiners interested in quantum-resistance strategies for Bitcoin.

We also felt the BIP deserved certain linguistic clarifications in light of the substantive technical changes made by coauthor Ethan Heilman earlier this year.

At its core, the BIP introduces a new Bitcoin output type that is both Tapscript-supportive and resistant to hypothetical long-exposure attacks on Elliptic Curve Cryptography (ECC). We have renamed this output type Pay-to-Tapscript-Hash (P2TSH) to reflect its construction more clearly.

Additionally, we’re working on follow-up proposals to introduce post-quantum signature schemes that may protect Bitcoin addresses from short-exposure attacks (that is, attacks on public keys while a transaction is in the mempool). P2TSH addresses will be well suited to integrate these signature schemes, laying the technical groundwork for future post-quantum signatures schemes in Bitcoin.

• We brought in Isabel Foxen Duke as our third coauthor to ensure the fullest clarity and to present the proposal’s motivation, rationale, and technical details as readably as possible.

• The proposed output type is now called Pay-to-Tapscript-Hash (P2TSH).

• P2TSH is Tapscript-supportive and removes the quantum-vulnerable keypath spend.

• The new output type lays the technical groundwork for future post-quantum signature schemes.

• We are developing quantum-resistant signature schemes and plan to introduce them in future proposals to protect Bitcoin from short-exposure quantum attacks.

• P2TSH will enable wallet optionality at spend time allowing Bitcoin users the choice of ECC as usual or ECC+PQC hybrid cryptography (so there is never a reduction in security)

• BIP 360 now includes complete test vectors in Python and Rust.

I want to thank everyone who takes the time to read, review, comment, and contribute. In particular, I’m grateful to everyone who’s participated on the Bitcoin BIPs repo on GitHub. I’m truly appreciative of all the time that Jon Atack, Murch, D++, Ava Chow, and many others have put into this so far. I’m particularly proud of how many amazing female contributors we’ve had so far, and we need to continue to encourage their contributions in our community.

I’m looking forward to reviewing all thoughts on the new work. This is the foundational critical work needed to make sure that Bitcoin is prepared for the future and our chance to address the quantum FUD once and for all.

While we still have many more challenges ahead, we believe BIP 360 is the next right action, paving the way towards a robust, multi-proposal quantum mitigation strategy for Bitcoin.

It’s also worth noting that today just so happens to be the 1 year anniversary of BIP 360 getting its BIP number courtesy of Jon Atack.

Thank you for your time,

Hunter