@Muhammad_Amir, while I have great respect for NGSoftware and they seem to have many happy, cloud-based users, please consider what you are asking. No software vendor is going to tell you their software is insecure or unreliable. That would be something like asking a fox if your chickens are safe in their coop.
Your best assurance is to scan this forum. Technical problems, you will find, are addressed with amazing speed. To my knowledge, no one has ever complained of security problems. Of course, no system is completely secure. We read almost daily of the most sophisticated organizations in the world being hacked.