Firewalls are just some stupid crap industry made up and went with. We've known since the Orange Book days that security had to be done holistically involving every endpoint and network. Their standard for security was a strong TCB on endpoint with trusted path (see EROS or Dresden's Nitpicker); a network card with onboard security kernel, firewall, and crypto (see GNTP + GEMSOS); connections between networks through high assurance guards (see Boeing SNS or BAE's SAGE); proxies + guard software for risky protocols such as email (see mail guards like SMG or Nexor). All of this collectively working together was what it took to enforce a fairly-simple, security policy (MLS). More flexible attempts happened in capability model with KeyKOS + KeySAFE, E programming language, CapDesk desktop, and so on.
So, the above was the minimum that NSA et al would consider secure against adversaries on their level. Every security-critical component was carefully spec'd, implementation mapped against spec 1-to-1, analyzed for covert channels, pen-tested, and even generated on-site. Commercial industry, aiming at max profit and time to market, just shipped stuff with security features but not assurance. Broke every rule in the field. Came up with firewalls (knockoff of guards), AV, and so on to counter minor tactics. Of course that didn't work as it doesn't solve the central security problem: making sure all states or flows in the system correspond to a security policy.
The best route is to put security in the end-point along with E-like tools for distributed applications and hardware acceleration of difficult parts. Within your trust domain, you just check data types and use that for information flow control (aka security). Outside trust domain, you do input validation and checks before assigning types. The hardware will be like crash-safe.org or CHERI processor in that it handles the rest. A security-aware, I/O offload engine will help too. Fixing the root problem along with a unified model (capability-based, distributed) will make most security problems go away. At that point, firewalls will be about keeping out the riff raff and preventing DOS attacks.
So, the above was the minimum that NSA et al would consider secure against adversaries on their level. Every security-critical component was carefully spec'd, implementation mapped against spec 1-to-1, analyzed for covert channels, pen-tested, and even generated on-site. Commercial industry, aiming at max profit and time to market, just shipped stuff with security features but not assurance. Broke every rule in the field. Came up with firewalls (knockoff of guards), AV, and so on to counter minor tactics. Of course that didn't work as it doesn't solve the central security problem: making sure all states or flows in the system correspond to a security policy.
The best route is to put security in the end-point along with E-like tools for distributed applications and hardware acceleration of difficult parts. Within your trust domain, you just check data types and use that for information flow control (aka security). Outside trust domain, you do input validation and checks before assigning types. The hardware will be like crash-safe.org or CHERI processor in that it handles the rest. A security-aware, I/O offload engine will help too. Fixing the root problem along with a unified model (capability-based, distributed) will make most security problems go away. At that point, firewalls will be about keeping out the riff raff and preventing DOS attacks.