A C++ Implementation of the Rijndael Encryption/Decryption method [here]. Article explaining how to decrypt a file in C# using Rjindael Algorithm [here] and [here].

Using the Rijndael algorithm implemented in C# (Microsoft gently provides it: "Rijndael Class"), of course. Veni, vidi, vici.

A common/open source method of working with SOAP/web services from C/C++ is using the gSOAP library. Here's the link: http://www.cs.fsu.edu/~engelen/soap.html[^] It really is relatively simple to work with, it may take a bit of a learning curve depending on your depth/breadth of knowledge in the area of C/C++ programming, sockets, web development (including services).

hServiceMGROpen=OpenSCManager(serverName,SERVICES_ACTIVE_DATABASE,SC_MANAGER_ALL_ACCESS); if(hServiceMGROpen!=NULL) { hServiceOpen=OpenService(hServiceMGROpen,"myService",SERVICE_ALL_ACCESS); if(hServiceOpen!=NULL) { succStart=StartService(hServiceOpen,0,NULL); if(succStart) { printf("Service starts successfully "); } else { DWORD err=GetLastError(); printf("Error %d",err); } } } this is my code....!!!! please findout problem....