1. A computer-implemented method of generating a common event format representation of information from a plurality of messages, comprising: parsing, by a computer processor, a rule associated with a current message to determine if a property of a common event format representation for the current message is to be populated with a property value from a previous message; obtaining, by the computer processor, the property value from the previous message if the rule specifies to obtain the property value from the previous message; and populating, by the computer processor, the common event format representation for the current message with the obtained property value from the previous message; wherein obtaining, by the computer processor, the property value from the previous message comprises: generating, by the computer processor, a computed key based on properties of the current message; and identifying, by the computer processor, the previous message based on the computed key of the current message.