I have been thinking more about trust and its importance in a computing environment.  Since there are so many ways to erode or remove trust altogether it seems that we need to do more to provide solutions to combat these attacks.

The key benefit with computing technology is that it is so dynamic.  This capability enables us to change anything in a nanosecond.  This is also a huge risk.  What would happen if you removed the element of change from a computing environment?  Would it cease to have value?  I think not.  I think that the recent surge of CD bootable OS images and virtualized images are merely one phase of this trust recovery process.  The next phase is creating "write-once" environments that cannot be modified by API.  Simply revoke ALL write API access to the disk.  Force all activity to occur in memory.  This of course has constraints, but systems are more powerful everyday.  Its only a few years away that we will have many GB's of memory in systems as a low end standard.

A write-once OS would improve the trust level it provides by preventing any changes to it on the fly.  The concern of course is that all of its flaws are persistent as well.  oh well, mankind has yet to make a perfect piece of software.  I guess we'll have to live with that human flaw.  A write-once OS should be as locked down as possible of course to reduce its attack surface area.  Of course data storage will need to happen elsewhere.  And session persistence is not a trustworthy goal as the session data needs to be stored elsewhere and could have been polluted/infected.

Now this is an area Linux could easily excel in.  The write-once OS.  This would need to be refreshed/recompiled (possible by the user as well) so any vulnerabilities or features can be released.  Sure, you need to download a 10-20GB image, but at least once you securly load it, you won't have any questions.

Perhaps its even possible to convert the concept to hardware - the hardware linux OS.  Not only is it not modifiable, but you never have to doubt it - ever.  This is merely a thought, I've no experience in OS design, but I suspect this is possible, just by forking linux.