1. A computer-implemented method of reducing fraud in transactions, comprising: obtaining, by a risk management engine, authentication history data from an authentication history server, the authentication history server comprising an archive of authentication operations performed or attempted using an authentication protocol that requires a user to provide an authentication credential prior to authorization processing; identifying, by the risk management engine, authentication process characteristics common to confirmed fraudulent transactions in the authentication history data; generating, by the risk management engine, rules based upon the authentication process characteristics; receiving, by a directory server, a verification request message from a merchant computer; receiving, by the risk management engine from the directory server, a request to perform a fraud assessment for a payment account that is being used to conduct a payment transaction prior to initiation of the authorization processing for the payment transaction; requesting, by the risk management engine and from the authentication history server, data regarding a history of authentication operations performed involving the payment account; performing, by the risk management engine, a fraud assessment process using the rules and the data requested from the authentication history server; determining, as a result of the fraud assessment process, by the risk management engine, that the risk of the payment transaction exceeds a specified threshold and is suspected of being fraudulent; and generating, by the risk management engine, and sending an early warning message to the directory server and an access control server at an issuer of the payment account prior to generation of an authorization request message, by the access control server, for the payment transaction to prevent generation of the authorization request message for the payment transaction.