A method of operation includes detecting that a wearable device is being worn, receiving a certificate from a primary device over a secure wireless link where the wearable device is paired to the primary device using the secure wireless link, storing the certificate in memory of the wearable device, and sending the certificate, over the secure wireless link, to the primary device to unlock the primary device. The method may further include detecting that the wearable device is no longer being worn, and eradicating the certificate from memory of the wearable device in response to detecting that the wearable device is no longer being worn. In some embodiments, the method may also include detecting that the secure wireless link is disconnected, and eradicating the certificate from memory of the wearable device in response to detecting that the secure wireless link is disconnected. The present disclosure also provides a wearable device.