Hardware token

A hardware token is typically small enough to be carried in a pocket or purse and often is designed to attach to the user's keychain. Some may store cryptographic keys, such as a digital signature, or biometric data, such as a fingerprint minutiae. Some designs feature tamper-resistant packaging, while others may include small keypads to allow entry of a PIN or a simple button to start a generating routine with some [display]] capability to show a generated key number. Special designs include a USB connector, RFID functions or Bluetooth wireless interface to enable transfer of a generated key number sequence to a client system.