Cryptography Lessons
Tracy r reed   |  

Security, Reliability, and the OS

I don't know if this will catch on or not but it is a very interesting
project. The goal is to make an extremely reliable and provably secure
operating system. I have not yet downloaded and played with it yet but
they seem to have a very good start. The OS started out as KeyKOS:

Then came EROS:

And now they are working on Coyotos:

There are really three remarkable things about this:

1. These are capability based operating systems. This is a much
better security model based on least privilidge than Unix uses. It is
designed such that side effects (buffer overflows) can be logically ruled
out, code proven, and a trusted computing base can be established.

2. They are creating a new language (I know, I hate it when people do
this, but they may have a good reason in this case) with stricly
formalized semantics to allow provable code which should result in far
fewer defects than any previous systems programming language.

3. KeyKOS and EROS were "persistant" operating systems. They have removed
this feature from Coyote but I am hoping they put it back. This means that
memory is really just a cache for disk and the whole thing is treated as
one big address space which has synchronization points and a form of
journalling. This means the entire state of the system is regularly saved
to disk and if the system crashes you can resume from where you left off.
It is similar to hibernation for laptops except it is happening all the
time so if you just pull the power or the system crashes you don't lose
all of your work. You could theoretically save the system, pull the drive,
put it into a different (perhaps upgraded or repaired or backup system)
and pick up where you left off.

I love the story in the link below about their little competition with

Here is a more detailed explanation: