Announcements

• Respect the privacy of participants
• Meetups are never recorded. We want everyone to feel comfortable participating and discussing the scheduled topics, anonymously if they wish
• (Probable) Location change for next bitdevs: La Cafebreria
• Join our Signal Group

Acknowledgements

• Thanks to Vinteum and Bitcoin Paraguay for the support

Warmup

• Buy Bitcoin from ueno? 🤔
• BIP-110 fail

Bitcoin (Core, protocol, wallets)

• BIP-54 / consensus cleanup: Murch-Zawy time-warp mitigation
  • Bitcoin Core #35949
  • Bitcoin Optech summary

Privacy / Cryptography / Research / Security

• Fedimint Lightning gateway fund-loss vulnerabilities
  • Report
  • Sweep
  • Security release: v0.12.1, also fixed in v0.11.3
  • Technical fixes: payment validation, timelocks and state-machine recovery
  • Actual incoming HTLC value vs sender-declared forwarding amount
  • Proposed gateway solvency checks and circuit breakers
• Liquid consensus inflation bug and ~4,000 BTC peg-out
  • Technical discussion
  • SideSwap incident report
• Babilonia: probabilistic CoinJoin disguised as covert betting
• BTCPay Server security follow-up
  • BTCPay Server 2.4.4 security update
  • API-key, LND and deployment hardening
  • Estimate of lost funds on August hack
• A case study of AI for security auditing

Lightning and L2

• Depots: probabilistic penalties for massively scalable self-custody