Chip
The key is created here.
A general phone runs mail, photos, and a browser at the same time. The security chip on this board has one job: create the private key for your crypto-based assets and refuse to export it.
Security model
The computer is a window. The device is the lock.
Yenao Wallet assumes the laptop at the other end of the cable can be untrustworthy. The private key stays on a dedicated chip. You read the request on the device screen before a signature is made.
Screen
The chip draws what you read.
Malware on a computer can imitate a dialog. It cannot repaint the screen that Yenao drives from inside the device. That screen is the record you check.
Button
Confirmation is physical.
A signature leaves the chip only after you hold the button. If the screen looks wrong, you simply do not hold it. The request stops there.
What the cable is for
USB-C powers the device and carries an unsigned request toward the chip. The private key does not travel back down the cable. What returns, after you confirm, is a signature made inside the hardware.
PIN
You choose a PIN of four to eight digits on the device. The PIN is a gate for the person holding the metal. It is not a copy of the key, and it is not typed into a website.
Recovery phrase
The 24 words are a backup of the key, shown a single time on the device screen. Write them on paper. Store the paper apart from the device. A photograph, a cloud note, or a message thread is the wrong place for those words. If the metal is lost or damaged, the phrase is how the key is restored onto a new Yenao Wallet.
Firmware
When firmware is replaced, Yenao asks the device to show a check on its own screen before the new code runs. You read that check on the hardware, the same way you read any other request.
No radio
The board has no wireless radio. There is no pairing step and no silent path onto the chip. The device is awake when the cable is connected.