In this chapter the security challenges raised by wearable technologies concerning the authenticity of information and subjects are discussed. Following a conceptualization of the capabilities of wearable technology, an authenticity analysis framework for wearable devices is presented. This framework includes graphic classification classes of authenticity risks in wearable devices that are expected to improve the awareness of users on the risks of using those devices, so that they can moderate their behaviors and take into account the inclusion of controls aimed to protect authenticity. Building on the results of the application of the framework to a list of wearable devices, a solution is presented to mitigate the risk for authenticity based on digital signatures.