Abstract: A distributed computer system employs certificate based alias detection to ensure a policy of separation of duties. Biometric information is collected during computer user account creation that is converted to canonical form and digitized. This digitized canonical form, along with account data and authentication data, is included in the user's account information. Authorization to execute any task is validated at the time a request is made by comparison of the digitized canonical forms of biometric data of the user completing the request with those of the user initiating the request.