Securing RFC/JCo Connections to the SLD 
ABAP-based systems use RFC/JCo connections for communication with the SLD server. This applies to the following communication routes:
Between an ABAP client that uses the ABAP API for the SLD and the intermediary J2EE Engine
Between data suppliers for ABAP-based systems and the SLD server
In both cases, you can secure the RFC connections by using Secure Network Communication (SNC). In addition, you can install the intermediary J2EE Engine on the same SAP Web AS instance so that the communication between the ABAP stack und the J2EE stack takes place locally.
For more information about Secure Network Communication (SNC), see .