Windows 8 introduces several new security features for enterprises, including UEFI Secure Boot which makes it difficult for malware to load during startup. Dynamic Access Control uses claims-based authentication to control access based on attributes rather than security groups. BranchCache caches commonly used files locally at branch offices to reduce wide area network traffic. DirectAccess provides seamless, always-on VPN access to allow remote employees secure access to corporate resources without requiring a VPN client.