Rant of the Week (ROTW): Trusted vs. Trustworthy

A common theme in computer security is "trust" -- and the implication that trust is equal to security is prevalent in quite a bit of literature and propaganda.  Although Wikipedia isn't the greatest source, it does provide some insight into popular beliefs, and makes for a good vehicle for this discussion.  Consider the article on the Trusted Platform Module, which starts with:

In computing, Trusted Platform Module (TPM) is both the name of a published specification detailing a secure cryptoprocessor that can store cryptographic keys that protect information, as well as the general name of implementations of that specification, often called the "TPM chip" or "TPM Security Device"

So what? Follow the links, and we get a little closer to some understanding:

A secure cryptoprocessor is a dedicated computer on a chip or microprocessor for carrying out cryptographic operations, embedded in a packaging with multiple physical security measures, which give it a degree of tamper resistance.

Scripting with Lua

For about two weeks, I've been planning to put together a way to generate test cases for one of my current projects. The project involves adding new capabilities to the RTEMS scheduler, and to test it I need to create RTEMS applications that spawn various periodic and aperiodic tasks. I already had written two such applications by hand, but I found it tedious to generate the parameters.

At a high level, the parameters are task type (periodic or aperiodic), duration (execution time), period, relative deadline, and release time (a.k.a. phase). To spawn tasks, I had some arrays defined in my RTEMS code of length equal to the number of total tasks. These arrays hold the values of the period, priority (relative deadline), release time, and execution time. Then my code uses the arrays to generate tasks with the given parameters. This isn't too difficult to write up by hand, but my project also requires that I compute some runtime characteristics of the periodic tasks.