Hey there @cryptodad I've tried installing sparrow and nunchuk and Avast keeps alerting me to possible trojans. I've even gone so far as to ensure I've downloaded the packages from official sites (Sparrow- I've checked certificates PGP keys, hashs etc.) and still get possible trojan alerts. Is there an antivirus that specializes with BTC enough to have analyzed the code for false positives etc? thanks in advance.

Because the device requires power. I mentioned that it is connected to a power brick, not my computer. There are battery powered chargers, but I consider this overkill. I'm not worried about hackers in my power outlets.

​​​@@CryptoDadAlthough unlikely it is possible the power brick can collect data from the CC. These days even regular usb cables have been known to have firmware in them that collects data transmitted through them and sends that to the hacker. Coinkite stocks a 9V battery connector to eliminate any doubts

@@CryptoDad why not just use a power bank?

@@pinoyrunningpenguina power bank could have a hacking device attached to it too. /s Amazes me the level of paranoia people have ! Jeez just use a USB instead. Coldcard and Sparrow are both open source. It's not like you are verifying the contents of the SD card and decrypting the hex values of the transaction signature or the PSBT. USB is actually more secure than using an SD card because SD card file can be manipulated as soon as it is connected to your computer. But a USB to sparrow wallet communication cannot be intercepted as easily as modifying a file on external storage.

The cards don't really have to know about new wallets. The cards have the master private key. If you've added new cryptos, using one card, then they will be on the app. When a signature is required from a card, it basically reads the master private key from the card. So any card will work. I'm just kind of spit balling here, but I'm pretty sure that's the essence of how it works. A good question by the way.

The only weakness I can see is if the private key momentarily leaves the secure chip and goes into a flash memory (similar to the Trezor physical hack flaw that was discovered) but I can't imagine that is how the Coldcard works. I'm sure they've learned from that mistake. They must run checksum algorithms on the files on the SDcard to ensure nothing malicious is entering the Coldcard, and the transaction is passed to the secure chip for signing and not the other way around. I don't know, it just mystifies me. I would have thought that passing the transactions via QR codes and a camera would be a better way to go. But then maybe there are malicious QR codes? Anyway, thanks for getting back to me!@@CryptoDad

Not hack but possible to steal data though ever difficult since it’s near field

I noticed that doesn't have any age spots either!

At least the AI version of me does.

@@user-be2nz3nb9q I totally agree. I’m not a huge fan of the cold card, but it is definitely one of the most secure solutions out there and has a big commitment to transparency. However, I would definitely not recommend it for beginners. You should check out my videos covering Ledger and Trezor, they are the most mainstream hardware wallets out there