With enough unique IP addresses to go around (and then some), organizations won't have to rely on NAT to connect to the Internet. IPv6 eliminates most of the address conflict issues common under IPv4, and enables more streamlined connections and communication for devices
When networking gurus and researchers developed IPv4 security hadn't really crossed their minds. IPv4 was never meant to be secure.
IPv6 has been built from the ground up with security in mind. Many of the security features that have been duct-taped after the fact onto IPv4 as optional features are integrated into IPv6 as default requirements. IPv6 encrypts traffic and checks packet integrity to provide VPN-like protection for standard Internet traffic.