Security protocols and technologies are most effective when considered at the start of architecting enterprise infrastructure or developing business processes, rather than being bolted on as an afterthought. The entire security landscape has changed in recent years and continues to evolve on an almost daily basis. No longer is it sufficient to simply wrap a firewall around your on-premises data center. There are now cloud platforms you must protect, and often multiple public clouds and hybrid cloud setups to safeguard as well.
