A method whereby a communication can be readily determined to be from an authorized sender or, conversely, identified as being from an imposter, wherein a digital token is created according to a set of at least two rules known to the creator and intended recipient of the communication, further wherein the digital token comprises a recognizable factor such as an image, word, or audio segment, and a system comprising means for implementing the method of the disclosure; wherein fraudulent messages may readily be identified by recognizing whether or not the digital token associated with the message complies with one or more pre-determined rules, even if the system presenting the message is unaware of the rules or even of the authentication process as a whole.