The point of airgapping isn't that QR'sbor SD cards are inherently more secure than USB or Bluetooth. It's that the amount of data is far more limited and easier to audit with lower tech methods.
If you ask me floppy disks would be even better, as SD cards have firmware that could be an attack vector. But floppies are prohibitively hard to implement in 2026.
You're The Voice | by Efrat Fenigson
Trezor's CTO on the Cold Card Hack: Randomness, Trust, and What Comes Next - Tomáš Sušánka | Ep. 153
By Efrat Fenigson
Aired Aug 7, 2026 · 1h 1m · Last boosted Aug 7, 2026
Chapters
Show Notes
Tomáš Sušánka is the CTO of Trezor, where he has worked since 2017. Tomáš joins Efrat for an urgent, unscripted conversation days after the Cold Card hardware wallet hack, in which a flawed random number generator left seed phrases vulnerable and resulted in more than 1,500 bitcoin stolen from affected users. Drawing on questions submitted directly by the Bitcoin community, Tomáš walks through what entropy actually is, how Trezor's own four-source random number generation works, why open-source visibility alone does not guarantee security, and what practical steps everyday self-custody users can take to reduce how much they have to trust any sing...
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Nostr Community
Everyone who has boosted Trezor's CTO on the Cold Card Hack: Randomness, Trust, and What Comes Next - Tomáš Sušánk… on Nostr, ranked by sats sent, all time.
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Cykros
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Other Episodes This Community Boosts Other shows' episodes boosted by people who boosted this episode
Nostr Boosts:1.6k
CykrosAug 18, 2026
1.6k A million times yes.
Thank you for addressing this in the right way. You're one of the only podcasts that hasn't responded to Coinkite with yet more bad options.
Very much excited that Learning Bitcoin From The Command Line is getting a new edition too -- long overdue.
Nostr Boosts:1k
CykrosJul 22, 2026
1k Re:other nodes and making news, you're clearly not watching Eric Voskuil on Twitter. Libbitcoin 4 just did IBD in 14 minutes on a consumer connection (with assumevalid height of 950k) and 55 min for full validation. Older than Knots, and older than Core being called, well, Core.
They slept for a good few years but are waking up with a vengeance.
May 19, 2025
Nostr Boosts:1k
CykrosMay 19, 2025
1k Thanks for removing the friction from consuming Mises.
Sep 21, 2026
Aug 24, 2026
Nostr Boosts:580
CykrosAug 24, 2026
580 Welcome back Walker, congrats on the bigger family
Also, xpubs will only give unhardened addresses.
That said, I expect a Venn diagram of people who didn't roll dice and people using hardened addresses is probably two separate circles.
Jul 16, 2026
Nostr Boosts:580
CykrosJul 17, 2026
580 This is sweet, thanks for covering this. Been getting excited listening to @npub1v25jqj332… talk about Stratum v2 for a while now. Nice to see it in action.
Nostr Boosts:580
CykrosJul 9, 2026
580 Welcome back
Sep 21, 2026
Nostr Boosts:500
CykrosSep 21, 2026
500 People would hit me with things suggesting Slackware to a Linux beginner, but you seem keen on appropriately following documentation, and it's got some of the best documentation, and very vanilla software which makes using upstream documentation easy to use too.
Some key audio thoughts too.
https://web.archive.org/web/20260426090835/https://blog.sla…
Doing your work you may want more than the standard pulseaudio back end.
Sep 17, 2026
Nostr Boosts:500
CykrosSep 18, 2026
500 Robinhood's 'tokenization' sounds more like an Exchange Traded Note (ETN) that is just a liability of Robinhood and traded on chain. These aren't new, but putting them on chain is.
The SEC is talking more about trading actual stock ownership using the chain as a ledger.
Very different despite the similar performance in ideal circumstances. If the stock goes up but robinhood goes under, you are out, while with the shares the SEC is talking about, you're good. Maybe a little market downtime, but you'd just get regular shares with SIPC coverage.
Nostr Boosts:500
CykrosSep 10, 2026
500 'Rear admiral' 😅
Tom Luongo calls him Big Gay Patton.
Still amused Trump brought us the highest ranking gay man in American history.
Sep 1, 2026
Nostr Boosts:500
CykrosSep 2, 2026
500 The outernet stuff you're looking for the name of is Reticulum I suspect. Works over lora, Bluetooth, wifi, TCP/IP, ham radio (illegally -- its encrypted), wires...pretty much whatever you want.
FIPS is another cool one you should all look at. Turns your npub into an IPv6 address. Talk to @npub1dergggklk… and Max Hillebrand
Aug 26, 2026
Nostr Boosts:500
CykrosAug 26, 2026
500 Hope this counts as a replacement for lost sponsor revenue per this listener.
Aug 4, 2026
Nostr Boosts:500
CykrosAug 4, 2026
500 The cloak and dagger shit with Switck is heating up. People were already looking for a reason for this to be inside. Still not totally convinced but it looks sketchy as fuck.
Never been more glad I had fun playing dice games with my bitcoin.
Jul 23, 2026
Nostr Boosts:500
CykrosJul 23, 2026
500 Boston Bitdevs is coming up on July 30 at MIT Building 4. Be sure to RSVP through bostonbitdevs.org (or with the link if David wants to put it in notes).
https://app.evento.so/e/evt_3M48gmwDKdbzNc63
Come with questions!
Jun 26, 2026
Nostr Boosts:500
CykrosJun 27, 2026
500 One of the best WBD's yet. Dines' coverage of the Eurodollar mechanics here and the shift that happened with LIBOR to SOFR is something far too few people are talking about (Luongo notwithstanding).
May 6, 2025
Nostr Boosts:500
CykrosMay 7, 2025
500 MOAR LUONGO
Dec 29, 2024
Nostr Boosts:500
CykrosDec 30, 2024
500 One of the best podcasts on the technical sides of Bitcoin I've encountered. Helps explain why IBD is taking forever on my raspi 4.
Sep 9, 2026
Nostr Boosts:430
CykrosSep 9, 2026
430 The thing about Bitcoin wallets is, you can have more than one. Soapminer? You're paying Lightning. Rent? Maybe a hot wallet, or single sig. Retirement savings? Multisig offsite. Generational wealth? You're adding miniscript.
You don't keep are your fiat in your pocket. Don't do it with your Bitcoin either.
Nostr Boosts:400
CykrosJan 6, 2026
400 Welcome back! Your break sounds like it was good. Missed your updates.
Mar 20, 2026
Nostr Boosts:210
Nostr Boosts:100
CykrosSep 22, 2026
100 Cutting out other forms of collateral is where stablecoins can drive up treasury demand. Currency swaps and other credit instruments are huge in repo markets, as is rehypothecation of the same underlying collateral. Stablecoins don't hold claims on treasuries, they hold treasuries. They don't hold gilts and forex swaps, they hold treasuries.
There are problems that come with some of the solutions here, as there mist be as the whole game of fiat is a game of jenga. But short to moderate term they can seem to cannibalize demand for other collateral and chains of rehypothecation in order to reduce treasury yields.
Sep 21, 2026
Nostr Boosts:100
CykrosSep 21, 2026
100 Infinite divisibility would be cool but floating point math is all sorts of problematic.
Infinite divisibility is trivial on L2+ though as it is.
Sep 14, 2026
Nostr Boosts:100
CykrosSep 14, 2026
100 He doesn't believe there was ever a major improvement to Bitcoin, but wants payment rails.
Yea, tell me you don't understand Segwit without saying so, especially while touting Lightning's use. Not surprised here.
Sep 10, 2026
Nostr Boosts:100
CykrosSep 11, 2026
100 The worst possibly blow arguably would have been nonce reuse. That'd have hit even the dice crowd.
Sep 2, 2026
Nostr Boosts:100
CykrosSep 10, 2026
100 ACK to more students coming out. Did you not hear @npub1fhmmgwe6f… say there's free food?😄
But seriously pushing the conversation back into classrooms and engaging other academics helps engage more valuable resources. Student engagement disporportionaly can help move the needle. Besides, the more you're into bitcoin when you're a student, the more you're retired when you're 45-50.
Nostr Boosts:100
CykrosSep 9, 2026
100 OpenArena is still out there and the zoomers can get off my lawn if they think I'm giving it up.
All the Q3 stuff is free on archive.org too, including team arena.
Fortnite is very centralized and permissioned. But Minecraft would work. Java version anyway, Idk about bedrock version.
Nostr Boosts:100
CykrosSep 8, 2026
100 A hard fork WILL be what saved bitcoin, if it is saved. If only because of the 2106 problem requiring it.
Sep 8, 2026
Nostr Boosts:100
CykrosSep 8, 2026
100 'Nobody runs an electrum server' 🤡
Let's just pretend EPS and electrs don't run trivially on a raspberry pi alongside your full node.
Sep 3, 2026
Nostr Boosts:100
CykrosSep 4, 2026
100 I don't get why everyone says random generation was the most important task. It'd have been a better signer than any on the market if it didn't have an RNG at all.
It was a task that if you're gonna do has to be done right though.
Aug 26, 2026
Nostr Boosts:100
CykrosAug 27, 2026
100 A hung jury isn't an acquittal, it's a mistrial. Jurors aren't voting, they're deliberating to arrive at consensus. If they can't, it's a do over.
Double jeopardy only applies if a verdict is reached.
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