Join Web3 Developers Underground on Wednesday, August 5th for an emergency technical breakdown of the Coldcard RNG failure—what actually broke, and whether your coins are at risk.
~1,816 BTC (~$114M) has been swept from about 5,294 Bitcoin addresses as of 3 August, across four suspected waves. It is still climbing. The wallets were ColdCards.
Almost every headline calls this a breach. It wasn’t. A March 2021 build-configuration error routed seed generation to a software PRNG instead of the hardware RNG. Seeds carried ~40 bits of entropy instead of 128. Attackers regenerated the keys offline — they never had to steal anything.
We called this session in 48 hours. One hour, three speakers, live Q&A.
The Panel
🎤 Avishay Yanai, Co-Founder & CEO, Soda Labs — cryptographer, PhD Bar-Ilan, ex-VMware Research. On the cryptography: what 40 bits of entropy costs an attacker.
🎤 Boaz Bechar, Ex-Citi | Open Source Developer — on what code review misses, and what a treasury on affected devices does this week.
🎤 Shauli Rejwan, Managing Partner, Masterkey VC · Co-Founder, Web3 Devs Underground — on what changes for anyone shipping security-critical code.
Moderated byAmit Shilo, Community Manager.
What we’ll argue about:
- Was this a hack, a bug, or negligence?
- Five years in a public repo — does “many eyes make bugs shallow” survive this?
- Does this prove self-custody doesn’t work?
- Nobody tested that the RNG output came from the RNG. Tooling, culture, or incentives?
And early on, the practical part: a live decision tree so you can tell whether your own coins are at risk.
Agenda (Israel time):
19:00 – 19:04 | Opening remarks and how to ask questions
19:04 – 19:09 | Round 1: what actually happened — three views
19:09 – 19:16 | Are your coins at risk? Live decision tree
19:16 – 19:38 | Rounds 2 & 3: how it broke, and was it avoidable
19:38 – 19:48 | Round 4: what changes now
19:48 – 19:58 | Audience questions
19:58 – 20:00 | One takeaway from each speaker
No price talk. No wallet recommendations. No attribution guesswork. Zero shilling, as always.
💡 Backed by Masterkey VC
Masterkey Venture Capital is a global early-stage fund focused on deep tech and Web3 infrastructure. With over five decades of experience in cryptography, infrastructure, cybersecurity, and energy, Masterkey backs visionary founders building the decentralized technologies of tomorrow.
Stay Connected
🐦 Twitter: https://x.com/Web3_Devs
📌 Telegram: https://t.me/web3devs_underground
🌐 Website: https://www.web3devs.org/
🔗 Linktree: https://linktr.ee/web3devsunderground
📺 YouTube: https://www.youtube.com/@web3devsunderground
Wednesday, August 5, 2026
🕔 Time: 7:00 PM – 8:00 PM IST
📍 Online
Live on X, YouTube & LinkedIn
✨ Web3 Developer Underground Israel is for those who are keen on developing and coding groundbreaking Web3 projects, smart contracts, and exploring the vast capabilities of related technologies.
Find Hotels Web3 Developers Underground Meetup