CASE STUDY
ROU_TITAN
Formally verified micro-kernel for high-assurance embedded systems.
PROJECT BRIEF
A formally verified micro-kernel written in Zig, designed for separation of concerns in secure embedded environments. The work focuses on a minimal trusted computing base, capability isolation, and reproducible verification artifacts.
TIMEFRAME
2025 - Present
ROLE
Kernel architecture, verification strategy, embedded systems research
STACK
PROBLEM
Embedded systems often accumulate privileged code paths until the security model becomes impossible to reason about. Titan needed a kernel structure small enough to verify while still practical enough to host real device, scheduling, and message-passing behavior.
The privileged core had to stay small enough for verification to remain practical.
The API needed to support real embedded workloads without leaking authority between components.
Build artifacts and proofs had to be reproducible across development machines.
Debuggability could not depend on compromising isolation assumptions.
APPROACH
The kernel was shaped around capabilities, minimal privileged surfaces, reproducible verification artifacts, and a strict separation between policy and mechanism.
Threat Model
We began by defining what a component should never be able to do by accident: access unrelated memory, signal unrelated tasks, or mutate device state without an explicit capability.
This made the kernel API a security boundary rather than just a convenience layer.
Verification
The verification strategy avoids a separate theoretical model that drifts from the code. Properties are attached to build and simulation workflows so regressions are caught before integration.
The goal is practical assurance, not ornamental proof language.
Bring-up
QEMU and hardware-in-the-loop tests were used to exercise scheduling, message passing, fault handling, and capability checks before direct target deployment.
This let the team separate kernel design failures from board-specific bring-up friction.
EVIDENCE
Trusted Core
Minimal surface
Kernel mechanisms are intentionally narrow so the verification target remains bounded.
Authority Model
Capability based
Components receive explicit capabilities instead of ambient access to shared resources.
Release Gate
Proof artifacts
Verification outputs are treated as build artifacts, not optional documentation.
ARCHITECTURE
The kernel offers scheduling primitives, IPC, memory isolation, and capability enforcement.
Device policy, service orchestration, and higher-level behavior are pushed outside the privileged core.
A component can act only through capabilities it has been granted. This makes permission transfer explicit and testable.
It also creates a clearer audit trail for what each subsystem can influence.
FIELD MATERIAL
SEQUENCE
01
Defined the minimum privileged responsibilities and excluded policy-heavy behavior.
02
Modeled component authority and message-passing constraints.
03
Integrated proof and simulation artifacts into the development flow.
OUTCOME
The project reduced the critical fault surface and created repeatable proof gates for core execution paths before broader hardware bring-up.
Reduced trusted surface
Security-critical behavior is concentrated in a smaller kernel core.
Clearer authority
Subsystem permissions are explicit and easier to audit.
Repeatable validation
Proof and simulation outputs provide regression signals for core behavior.
LESSONS
01
Verification gets more valuable when the implementation is designed to be verified.
02
Capability systems force architecture conversations earlier, which is usually where they belong.
03
Small kernels are only useful when the surrounding system respects the same boundaries.