PIN Protection on Cypherock X1
Cypherock X1 has a unique mechanism with regards to PIN protection. Cypherock uses an alphanumeric PIN system that a user can choose between 4-8 characters to add an extra layer of protection on top of each of the 4 wallets the user creates on Cypherock X1. When the PIN is generated, the hash of the PIN is created to encrypt all 5 cryptographic parts in Cypherock X1.
The double hash of the PIN is stored on each X1 Card and is used to fetch the cryptographic parts stored on the respective X1 Card. When a user enters a pin on the X1 Vault, the double hash of the PIN is calculated and sent as input to the X1 card to compare against the stored value in the X1 Card. On successful verification, the cryptographic part is retrieved from the X1 card. The X1 Vault has access to PIN (and its subsequent hash) only for the session of time in its RAM. No information about the PIN is permanently stored on the X1 Vault. Whenever a user enters a PIN it is erased right after it's used.
PIN protection on the X1 Card also comes with an exponential time function. This means that a series of wrong guesses on the PIN can lead to the wallet being locked for up to 100 years. To learn more about the locking mechanism, refer to Cypherock's Github page dedicated to talking about the locking mechanism with PIN protection.