The security-related problem during the data exchange is not considered in the SyncML protocol. To solve this problem, SyncML is enhanced with a secure data synchronization exchange service application program interface （SDSXS-API） to ensure the reliability, the integrity, and the security in the data transmission and exchange. The design and the implementation of SDSXS-API are also given. The proposed APIs can be conveniently used as a uniform exchange interface for any related application programs. And their effectiveness is verified in the prototype mobile database system.
