Announcements

• Respect people’s privacy
• Interaction and asking questions are encouraged
• Chatham House Rules
• Bitcoin 2025
• Bitcoin Designathon
• BTC in D.C.

Semi-Regular Installment of Bitcoin Trivia!

• trivia

Topics

Urgent

• NBitcoin Crash and fix
  • Miners rolling nonstandard tx version numbers
• NBX Explorer Nix-bitcoin Fix
• Coinbase PII Breach & $20M Ransom

Stats

• Mining Centralization Index
• Cumulative OP_RETURN Output Values
• OP_Return Update
• LN Wallet Marketshare in Japan
• Mempool.Space Lightning

Knots node % growth

• @freeonlineuser
• @SuperTestnet
• @sr_gi
• @lopp

Misc.

• Peach GroupHug
• Musig2 module merged in rust-bitcoin rust-secp256k1
• BIP30 consensus failure vulnerability
• LND 0.19.0-beta.rc4 - new RBF-based fee bumping for cooperative closes
• Standardized backup for wallet descriptors
• script type value 3 for taproot (P2TR) derivations in deterministic multisig wallets with the m/48’ prefix
• Bitkey self-custody
• Coldcard co-sign
• cve-2025-43707/
• Post Quantum Signatures and Scaling Bitcoin
• Removing checkpoints in Bitcoin Core v30
• Hourglass BIP
• 64-bit arithmetic in Script
• Legacy wallet removal

Research

• Round-Efficient Adaptively Secure Threshold Signatures with Rewinding
• Thunderbolt: A Formally Verified Protocol for Off-Chain Bitcoin Transfers
• ECDSA Cracking Methods

Mining

• Parasite Pool

Filter Wars (“Core Dev”s versus “Pleb Podcasters” LARP)

• Relax OP_RETURN standardness restrictions
• PR closed - Remove arbitrary limits on OP_Return (datacarrier) outputs #32359
• Rebuttal arguments against lifting filter limits for OP_RETURN

For

• Pieter Wuille

Against

• Jason Hughes

Recent Developments

• Policy
• F2Pool quietly dropped their minimum relay fee
• Non standard txs mined since last halving
• Brc-20 in op_return
• More non-standard txs and mempool shenanigans
• Cost of sending large op_returns with filters
• Garabageman
• Tx-Pigeon
• Largest OP_Return
• Private Mempool services
• Hop-Return, new op_return based metaprotocol
• Runtime BTC Knots policy changes
• Circumventing filters
• 4kb of data in the control block