A requesting message processor identifies client security input data of a first format and encapsulates the client security input data within a client security token. A requesting token processing interface sends the client security token to a validating message processor. A validating token processing interface at the validating message processor receives the client security token. Based on the encapsulated client security input data, the validating message processor selects client security output data of a second format. The validating message processor encapsulates the security output data within a response security token. The validating token processing interface sends the response security token to the requesting message processor. The token processing interfaces can be configured to similarly abstract security input data and security output data so as to increase the possibility of compatible communication between the requesting and validating message processor.