Day 1 - Foundations & Problem Statement⚓

📌 Course Day Overview⚓

Theme: Why digital trust matters. Foundations of modeling for secure hardware.

Learning Objectives: - Understand the collapse of digital trust and human harm - Contextualize the HSP-PCB project within IoT sovereignty - Introduce design thinking for hardware security - Establish threat modeling as a design principle

🔐 The Crisis: Digital Trust Has Collapsed⚓

Context: Loss of Autonomy⚓

Over the past two decades, digital systems have become essential infrastructure for commerce, communication, governance, and identity. Yet this infrastructure has been systematically compromised:

Manufacturers Exploit Users⚓

Smartphones ship with backdoors, spyware, and forced telemetry
Devices collect intimate behavioral data without consent
Hardware is engineered to fail, forcing unnecessary replacement
Repair is criminalized through DMCA enforcement

Cloud Providers Monetize Privacy⚓

Data brokers aggregate intimate information about billions of people
Third-party tracking is ubiquitous across web & mobile ecosystems
Governments demand backdoor access; corporations comply without warrant
"Free services" are the product—not users, but their data

IoT Systems Amplify Exposure⚓

Smart homes, vehicles, wearables, and industrial systems leak data continuously
Most IoT devices have no security updates, no recovery path
Supply chain attacks compromise hardware before it reaches users
Decentralized systems (vehicles, medical) become single points of control

The Harm: Real Human Impact⚓

Political prisoners tracked through location data
Undocumented immigrants persecuted through biometric systems
Women subjected to stalking through smart device hijacking
Communities surveilled through weaponized algorithms
Autonomy is lost when data becomes liability

🎯 The HSP-PCB Solution: Human-Sovereign Privacy & Security⚓

Problem Statement⚓

How can we build hardware infrastructure that restores human autonomy in digital systems while remaining: - Verifiable (not a black box) - Repairable (owned & maintained by users, not corporations) - Modular (integrated into diverse systems—vehicles, homes, devices) - Sustainable (engineered for long lifecycle, not planned obsolescence)

What HSP-PCB Solves⚓

The Human-Sovereign Privacy & Security PCB (HSP-PCB) is a tamper-detecting, cryptographically-hardened security coprocessor designed to:

Verify Hardware Integrity — Detect unauthorized modifications, cloned devices, or supply-chain tampering
Protect Cryptographic Keys — Isolated key storage with tamper response (secure deletion)
Enable Privacy-First IoT — Serve as trust anchor for vehicles, homes, and portable devices
Maintain User Control — All schematics open for inspection; repairable by trained technicians
Prove Authenticity — Zero-knowledge proofs of device legitimacy without data leakage

🏗️ Design Philosophy: Security by Design⚓

Principles⚓

Principle	What It Means	Example
Verifiable	All design decisions must be visible & auditable	Open schematics in KiCad; git history of every change
Recoverable	Systems must survive failure & maintain availability	Graceful degradation; no kill switches; repair manual
Modular	Components must compose without creating new vulnerabilities	Plug-and-play integration; standardized interfaces
Minimal Trust	Reduce reliance on corporations or governments	Open-source firmware; community-auditable code
Transparent Threat Model	Publish what we can & cannot defend against	Threat matrix; attack surface documentation

📋 Threat Landscape: What We're Defending Against⚓

Threat Categories⚓

Threat	Attack Vector	HSP-PCB Defense
Supply Chain Tampering	Microcontroller replaced with spy chip	Tamper detection casing; trace continuity sensors
Hardware Cloning	Legitimate devices copied by adversaries	Cryptographic attestation; unique key per device
Key Extraction	Physical attacks (side-channel, fault injection)	Tamper-responsive secure deletion; isolation
Firmware Modification	Malicious code injected into firmware	Signed boot; immutable boot loader; flash protection
Physical Tampering	Solder joints scraped, traces cut, components moved	Pressure sensors; laser tamper-detection grid
Cold Boot Attacks	Memory extracted while powered (DRAM not cleared)	Encrypted key storage; volatile-only crypto keys

Threats We Do NOT Defend Against⚓

Quantum computing (future concern; key length > 256 bits for post-quantum prep)
Insider threat (manufacturer compromises device at fabrication)
Nation-state adversary with unlimited resources (physical reverse-engineering)
User negligence (user hands device to attacker)

🛠️ Modeling Foundation: Design for Security⚓

Design Approach⚓

To make HSP-PCB work, we must integrate security into the physical design:

Form Factor Constraints — Credit-card size + <2.5mm thickness - Limits what sensors we can embed - Affects power consumption & thermal stability - Requires tight mechanical tolerances
Threat Detection Sensors — Embedded in PCB layout - Pressure sensors (detects physical stress) - Trace continuity sensors (detects wire cutting) - Temperature sensors (detects targeted heating) - Laser sensors (optional: detects optical probing)
Enclosure Integrity — Mechanical design must support sensing - Metal casing (Faraday cage + structural integrity) - Sealed ports with tamper detection - Modular attachment points (for different IoT contexts)
Power & Thermal — Design for secure failure - Isolated power domains (sensitive circuits shielded) - Low-power operation (battery-based deployment) - Thermal shutdown triggers secure deletion

📊 Day 1 Deliverables⚓

What We Document Today⚓

✅ Executive Summary — 1-page overview of HSP-PCB
✅ Problem Statement — Why digital trust matters
✅ Threat Landscape — Categorized attacks & defense mechanisms
✅ Design Philosophy — Security-by-design principles
✅ Success Criteria — What makes HSP-PCB a success

Key Artifacts⚓

docs/
├── day_1.md              # This document
├── images/
│   ├── day_1/
│   │   ├── threat_landscape.png
│   │   ├── design_philosophy.png
│   │   └── trust_collapse.png

🧠 Reflection: Why This Matters⚓

Context⚓

Modeling is not just about shapes and dimensions. It's about solving structural failures in systems.

The HSP-PCB project begins with understanding a structural failure in digital trust: - Trust was delegated to corporations → They betrayed it - Governments mandate backdoors → Citizens become monitored - Devices are designed to fail → Autonomy becomes costly

Our model (the PCB) is a response to this structure.

What We're Really Building⚓

The PCB is not just a circuit board—it's an artifact of sovereignty: - For the user: Proof that their device is theirs, not rented - For the community: A replicable, auditable security standard - For society: An existence proof that trustworthy hardware is possible

Tomorrow's Work⚓

Tomorrow, we translate this vision into digital models: CAD outlines, block diagrams, and parametric constraints that engineers can manufacture.

🔗 Resources & Further Reading⚓

On Digital Trust Collapse⚓

EFF: Surveillance Self-Defense
Shoshana Zuboff: The Age of Surveillance Capitalism
Bruce Schneier: Click Here to Kill Everybody

On Hardware Security⚓

Tools We'll Use⚓

KiCad: kicad.org
FreeCAD: freecadweb.org
Git & GitHub: github.com/ernestonkunzimana

Status: Day 1 Complete ✅
Next: Day 2 - Digital Modeling & Architecture
Last Updated: January 31, 2026

Digital Modeling⚓

Initial Concept Sketching⚓

Before jumping into CAD, I started with hand sketches to explore the design:

Sketch 1: Layout Options - Explored different letter arrangements - Tested oval vs. rectangular outer shapes - Considered proportions and visual balance

Sketch 2: Dimensional Planning - Overall dimensions: ~150mm x 90mm oval - Letter height: ~40mm for "C", "O", "3" - Depth of cut: 3-5mm for dramatic shadows - Border thickness: 10-15mm around letters

Design Decision: Selected oval shape with vertically-stacked "CO3" for optimal visual impact and material efficiency.

Initial Draft: My first concept sketch transitioning from analog to digital modeling - exploring layout options and proportions for the CO3 nameplate

Modeling Workflow⚓

Modeling is more than just creating a shape; it is the representation of form, logic, and behavior. My workflow incorporates two distinct approaches:

Geometric Modeling: Defining static shapes and physical dimensions.
Parametric & Rule-Based Modeling: Using parameters to enable variation without needing to redesign the entire object.

Design Decisions⚓

Every design choice was made with the understanding that fabrication method is a design choice.

Parametric Thinking⚓

By utilizing parametric thinking, I treat my models as research tools. This allows me to: * Test assumptions about fit and function. * Quickly adjust variables when physical constraints change.

The CO3 nameplate design we will create throughout this course

Fabrication Logic⚓

Fabrication Paradigms for the CO3 Nameplate⚓

To transform my digital model into physical reality, I considered multiple fabrication approaches:

Option 1: Laser Cutting (Subtractive) - Pros: Fast, precise, clean edges - Cons: Limited to 2D cutting, no depth variation - Best for: Flat nameplate with through-cuts

Option 2: CNC Router Milling (Subtractive) - Pros: Can create depth, 2.5D carving, professional finish - Cons: Longer fabrication time, requires tool changes - Best for: Carved lettering with depth

Option 3: 3D Printing (Additive) - Pros: Rapid prototyping, complex geometries - Cons: Visible layer lines, requires extensive finishing - Best for: Initial prototypes and design validation

Decision: I will use CNC router milling for the final piece due to its ability to create depth and professional surface finish. However, I'll start with a 3D printed prototype to validate the design.

Material & Tolerance Considerations⚓

Real-world fabrication introduces physical constraints that digital models often ignore.

Designing for Imperfection

As noted in our coursework, real-world fabrication inevitably introduces error and deformation.

Tolerance: I designed my parts with specific tolerance limits to ensure proper fit despite machine inaccuracy.
Material Behavior: The choice of material actively influenced the design outcome, requiring adjustments for shrinkage and flexibility.

Prototyping & Iteration⚓

Rapid Prototyping Strategy for CO3 Nameplate⚓

Prototyping validates design decisions before committing to final fabrication.

Phase 1: Paper Mockup (Day 1)⚓

Purpose: Validate size and proportions Method: Print 1:1 scale outline on paper Result: Confirmed 150mm x 90mm oval feels appropriately sized

Phase 2: 3D Printed Prototype (Day 6)⚓

Purpose: Test letter depth, overall aesthetics, and design refinement Material: PLA plastic Timeline: 2-3 hours print time Validation: Check letter legibility, depth effectiveness, overall visual balance

Phase 3: Test Cut on Scrap Material (Day 7)⚓

Purpose: Validate CNC toolpaths and cutting parameters Material: Scrap plywood Result: Refine feeds, speeds, and depth settings

Phase 4: Final Fabrication (Day 7-8)⚓

Material: Aluminum 5052-H32 or FR-4 PCB Process: CNC milling, PCB etching, and assembly Finishing: Anodizing, conformal coating, final testing

Reflection – Lessons Learned & Critical Analysis⚓

Day 1 Achievements⚓

Today marked the beginning of the HSP-PCB project. I established: - Clear security threat model and requirements - System architecture concepts and component selection - Fabrication strategy (PCB manufacturing, CNC enclosure milling, assembly) - Development timeline across the course

The Iterative Process⚓

The most important lesson from this module is that the process is iterative, not linear. For the CO3 nameplate: 1. I started with rough sketches to explore layout options 2. Defined critical dimensions and proportions 3. Planned a multi-phase prototyping approach 4. Selected appropriate fabrication methods for each phase

Design Thinking for the CO3 Project⚓

Question: Why an oval shape? Answer: The oval provides visual softness while maximizing usable surface area and creating an elegant frame for the letters.

Question: Why vertically stacked letters? Answer: Vertical stacking creates a strong visual axis, ensures letter legibility, and works well within the oval proportions.

Next Steps for Day 2⚓

Tomorrow I will: 1. Create the precise CAD model in FreeCAD 2. Define exact dimensions and tolerances 3. Export files in multiple formats (STL for 3D printing, DXF for CNC) 4. Validate the digital model against design requirements

Final Learning Outcomes⚓

Through Day 1, I have learned to: 1. Start with clear project requirements before designing 2. Sketch before modeling to explore options quickly 3. Plan the entire fabrication workflow from the beginning 4. Select appropriate processes for prototyping vs. final production

Key Insight

\"The best designs emerge when fabrication logic informs the design process from day one, not as an afterthought.\"

Visual Reference Gallery⚓

FabLab - Digital Fabrication Foundation