System Design Index
This folder contains the structured system design for the offline NFC wallet system. It defines the concepts, state model, and security assumptions.
System design focuses on the model and intent. Tech specs are the implementation reference for developers.
Sections
- Core Objective
- Hardware Constraints
- Security Model
- Card State Machine
- Data Layout
- Log Chain Model
- Trailer / Meta
- Cryptographic Model
- Write Strategy (A/B Buffer)
- Verification Rules
- Card Status Enforcement
- Key Trust Model
- Client Roles
- Transaction Log Structure
- Blocked Status Rules
- Infrastructure Stack
- Validation Assumptions
- Card Initialisation State