The present invention relates to a combinatorial method for security from cloud. The object of the proposed invention is to combine / integrate various security services for user applications to be delivered as cloud service. This approach has given users option to get various security services from cloud in an intelligent and transparent manner. Herein one public cloud setup used is proprietary private cloud and other public cloud used is Microsoft Azure cloud setup. The implementation has been done in form of a web servers running under windows OS Virtual machines. The overall overhead depends on the traffic in public cloud, but it does not increase beyond 15-20%, which is fairly good given the advantages it offers over legacy systems. Following invention is described in detail with the help of Figure 1 of sheet 1 showing the working of combined Security-as-a-Service (SecaaS) model.