Learn in the textbookThe 7 Elements of Information Security
DefinitionAuthenticity (真正性) is the property that users, information and communication partners can be confirmed to be genuinely who or what they claim to be.
ExplanationAuthentication, which confirms identity, prevents impersonation, where someone pretends to be another person. What gets checked is not limited to people; it also covers the devices on the other end and the origin of received data.
AnalogyIt is close to checking a courier's uniform and staff ID to make sure they really work for the delivery company before opening the door.
Memory hookThe Japanese 真正 combines "true" and "right". Authenticity comes from authentic (genuine) and belongs to the same word family as authentication.