Developers advance post‑quantum plans as Bitcoin Core 31.0 lands; fees and throughput stay muted

May 9, 2026 — Bitcoin protocol work around post‑quantum outputs and a proposed migration/sunset plan advanced into public review as Bitcoin Core 31.0 reached release candidates; on‑chain activity and miner revenues remain subdued, keeping short‑term market frictions low.

Developer snapshot: what shipped and what’s in review

• Bitcoin Core 31.0 completed release candidates in March–April and published release notes and binaries; the release includes the new mempool model and multiple RPC/usability changes relevant to node operators and wallet implementers. Release notes.
• BIP‑360 (Pay‑to‑Merkle‑Root / P2MR) is specified in the BIPs repository as a new output type intended to remove Taproot key‑path exposure and reduce long‑term public‑key surface for future quantum‑resistance concerns; wallet and library maintainers should review the spec and upstream test vectors. BIP‑360 (mediawiki).
• BIP‑361 (Post‑Quantum Migration & Legacy Signature Sunset) is a multi‑phase draft that proposes a time‑boxed migration and an eventual sunset of legacy ECDSA/Schnorr spends for vulnerable UTXOs; it sets tentative activation mechanics and describes phased incentives and guardrails. BIP‑361 draft.
• PSBT / silent‑payment plumbing (BIP‑376) — a pull request formalizing PSBT fields to support silent‑payment spending flows — is active and referenced in Core testing and Optech notes. Implementers should track the PR and testnet vectors. BIP‑376 PR.

“This proposal follows the implementation of any post‑quantum (PQ) output type and introduces a pre‑announced sunset of legacy ECDSA/Schnorr signatures.” — BIP‑361 abstract

Data: on‑chain throughput and fee market (24h / 7d / 30d context)

Public fee and throughput indicators show a calm fee market as these protocol discussions progress. Median recommended fee tiers remain near the low levels seen since 2024: mempool.space’s fee chart shows sat/vB bands clustered at single‑digit values and a low mempool backlog, indicating little short‑term congestion pressure for typical transactions. mempool.space (mempool & fee tiers).

Confirmed transactions per day have trended modestly higher versus early 2025, but fee revenue as a share of block reward is still low compared with historical congestion periods. For transaction counts and broader throughput context, see Blockchain.com’s transactions per day chart. Transactions/day (Blockchain.com).

Mining and security context

Hash‑rate remained elevated through Q1–Q2 2026, with weekly public aggregators reporting averages in roughly the 900–1,050 EH/s band; sustained hashing protects against short windows of reorg risk but also raises the bar for any soft‑fork coordination. Network hash‑rate (Blockchain.com).

On May 2, 2026, public reporting noted a ~2.30% mining difficulty drop — a modest correction that slightly eases miner pressure on short notice. Because BIP‑361 explicitly ties incentives and fee economics to migration timelines, even small adjustments in miner economics can affect upgrade cadence and relay/mining policy decisions. May 2 difficulty report (KuCoin).

Practical takeaways — What this means

• Traders & PMs: treat post‑quantum migration as a multi‑year tail risk with asymmetric impact; monitor stated activation windows (e.g., BIP‑361 timestamps) and avoid knee‑jerk positioning on speculative dates.
• Custodians & exchanges: draft migration mechanics in BIP‑361 and the P2MR output in BIP‑360 require concrete rehearsals and playbooks. Begin testnet migrations and custodial reconciliation plans now if proposals advance toward activation.
• Wallet & infra teams: review Bitcoin Core 31.0 release notes and the BIP‑360 / BIP‑376 specs; add CI tests for P2MR spending paths and the new PSBT fields to ensure forward compatibility.
• Node operators & miners: run current RCs in staging and track miner policy changes; miner relay/mining policy could become an economic lever if activation windows are tightened.

Next checks for technical and risk teams: watch the bitcoin/bips repository for PR updates and testnet sign‑off on P2MR implementations, follow Bitcoin Core announcement channels for any changes to release parameters, and monitor mempool fee trends for user responses to upgrade windows. Relevant primary documents and repositories: Bitcoin Core v31.0 release, BIP‑360, BIP‑361, and the BIP‑376 PR.