1. An authentication method, the method comprising: receiving from an initiating user, by a security tool, a request for a transaction; performing, by the security tool, a first authentication of the initiating user for the transaction, the first authentication employing a first authentication level; determining, by the security tool, an observed confidence level that indicates a degree of certainty with respect to accuracy of the first authentication; comparing, by the security tool, the observed confidence level of the first authentication with a predetermined confidence threshold to determine if the observed confidence level exceeds the predetermined confidence level; authorizing the transaction to proceed, by the security tool, if the observed confidence level exceeds the predetermined confidence threshold; halting the transaction, by the security tool, if the observed confidence level fails to exceed the predetermined confidence threshold.