We have entered an era where our commercial transactions are increasingly being conducted online without any face-to-face interaction, and without the traditional safeguards used to confirm that a party is who they purport to be. The attenuated nature of many online relationships has created an opportunity for criminal elements to steal or spoof online identities and use them for monetary gain. As such, the ability of one party to authenticate the identity of the other party in an online transaction is of key importance.To counteract this threat, the business community has begun to develop new authentication procedures to enhance the reliability of online identities (so that transacting parties have a higher degree of confidence that the party on the other end of an electronic transaction is who they say they are). At the same time, the law is beginning to recognize a duty to authenticate. This blogpost post looks at two online banking breach cases to examine what courts are saying about authentication and commercially reasonable security.