Cupcake: smartphone‑based signing device.

[satscraper]

I have recently come across an interesting solution called Cupcake , which allows you to turn the old Android or iOS smartphone or tablet into the air‑gapped hardware signing device ^{aka cold wallet}.

Unlike  Cryobrick , which we discussed earlier, Cupcake is completely free, open‑source, air‑gapped, and not tied to any specific mobile device.

 I think this solution is worth considering for anyone who cannot afford to buy a dedicated hardware wallet.

The accompanied software client for Cupcake-based signing device is well known Cake Wallet.

The technical deep‑dive can be found here.

The latest firmware release is v.1.1.0.

[SFR10]

which allows you to turn the old Android or iOS smartphone or tablet into the air‑gapped hardware signing device ^{aka cold wallet}.

For those who'd like to try this approach, it's better to use a phone with hardware-level secure enclaves ^{[e.g., older entry-level Android phones tend to lack them]}.
^{- Even though they mentioned in the latter part of the "Security at rest" section that for phones without such things, they'll "enforce a multi-layered secure storage approach, capable of preventing most types of attacks", there's always going to be some risks!}