How do you prove it can't be reached by wifi? Turning wifi off doesn't prove wifi cannot be used by an attacker via some sort of exploit.
How do you prove it can't be reached by bluetooth? Turning bluetooth off doesn't prove bluetooth cannot be used by an attacker via some sort of exploit.
My airgapped laptops had the wireless components physically removed for both Bluetooth if there was any, and for the Wi-Fi. My airgapped computers always had motherboards with no wireless connectivity at all. I agree, if it is simply an 'Airplane Mode' switch on a screen then it is useless.
I saw this Software Wallet designed for turning old Smart phones in to 'Hardware Wallets'. I would never use that. A Smart phone has a SIM card, Bluetooth, Wi-Fi, NFC, what not. So many ways it can transfer information to the external World, which should be a concern.
How do you prove every line of code running on that computer is safe and cannot be used by an attacker to steal your coins? Not just every line of code in the app. Every line of code on that machine, period, including the OS.
I can not really prove much as I do not have the knowledge to audit a code on my own. I could use 'AI', but that would be less trust worthy than humans who audit the code and even if it was just as reliable, to me it would be just like trusting a human audit of the same code.
However. Installing an encrypted Open Source Linux distribution and pairing it with an Electrum install, how can an attacker realistically steal my Bitcoin?
I am talking particularly about average users, not about people who are stalked by the CIA, NSA or which ever other Three Letter Agency. For that threat level you would need hell of a lot more paranoia.
If plausible deniability is a worry, a gigantic 15 inch laptop or an enormous computer case with an encrypted Linux install would be one quick way to get your first bat to the face by the attacker. But then you can always have a normal Linux install with normal Open Source software and files on it so if the attacker opens it up there is no thing to get out of it, and then you can have a small, hidden, encrypted USB Linux install that you plug in when ever you want to boot in to the Electrum install.
Part of the point of hardware wallets like Trezor is that a single-purpose device helps keep you safe by removing security risks introduced by other uses, such as wifi, bluetooth, apps, extraneous code, etc (this is also why I'd never use a Trezor model with bluetooth. Why add that risk?).
I agree. These 'modern designs' with wireless connectivity have been a big worry for me for a long time. I believe Ledger was first with their Nano X, and then it became a competition for who can bring most wireless features and the best design while still being able to offer the same level of security. It defeated the purpose of a Hardware Wallet. If I can back up my Seed in a cloud service and I can transfer Bitcoin using Wi-Fi or Bluetooth, I could as well simply carry all my Bitcoin on a Hot Wallet. It would be the same!
Trezor at least kept two separate paths for people who prefer wireless connectivity and people who prefer the classic way. I lost my interest in Hardware Wallets many years ago however as I always simply went back to my Electrum setup instead.
-----
I do hope you do not understand me wrong. By the way it looks, you are about as paranoid as me when it comes to this technology. I do not deny that a Seed Signer is a solution for people who want top notch security for their Bitcoin, particularly now when even devices like Trezor are found with implants. It is really bad and uncertain times we are living. I however feel like an airgapped setup is also a great solution, for multiple reasons.
A lot of people have old technology in their home, which means all they need for this setup is to get one of their old laptops or computers, identify each component and remove any wireless one physically from it, install an encrypted Open Source Linux distribution and then install Electrum.
Satoshi created an alternative to Fiat, to Banks, a way for the unbanked to be their own Bank. I see my approach as a way to fulfill that, by making it possible for people who already own the older technology in their home to build their own Bank from scratch with no extra investment other than time. You recycle an old device, giving it great use.
I know many people who still own computers or laptops from before Bitcoin even existed. The oldest computer I tried to airgap was a pre 2005 build. It took about two to three minutes from pushing the Power button to loading Electrum but after that it would work with no problems at all. While a Seed Signer does seem to have a lot of cool features and is a viable, affordable solution to secure your Bitcoin, is it not wrong to spread the word that an airgapped Electrum install is 'reckless' in comparison to it?