About a decade ago I worked on a project for secure networks where machines would encode identity information into the lower 64 bits of an IPv6 network and secu

About a decade ago I worked on a project for secure networks where machines would encode identity information into the lower 64 bits of an IPv6 network and security devices could use that to enforce policy based on your identity, not your machine. The most interested customer, the government, had the problem of having way too much IPv4 space and little incentive to upgrade so it never went anywhere. Even after the government mandates to switch to IPv6, which mostly just ended up with loads of IPv4 only government websites behind Cloudflare gateways.