The Mystery of Hardware Wallet Memory

Hardware wallets are unusual in terms of modern app development. The memory of a hardware wallet is its most critical and vulnerable part, as it is where private keys and other sensitive information are stored. To limit physical attacks and exploits, hardware wallet suppliers intentionally make the memory extremely small. One hardware wallet has only 4kB of available operating memory. In fact, most of that memory is also used for low-level logic and functions such as display, leaving only about 1.5kB for our app's logic.