smoa/docs/architecture/ARCHITECTURE.md

SMOA System Architecture

Version: 1.0
Last Updated: 2024-12-20
Status: Draft - In Progress

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System Overview

The Secure Mobile Operations Application (SMOA) is a hardened Android-based application designed for deployment on approved foldable mobile devices. SMOA enables identity presentation, secure internal routing, and mission communications in connected, disconnected, and degraded environments.

System Purpose

SMOA provides secure mobile operations capabilities for government and military personnel, including:

• Digital credential presentation
• Secure communications
• Orders management
• Evidence chain of custody
• Regulatory reporting
• Domain-specific operations (law enforcement, military, judicial, intelligence)

System Context

SMOA operates in a secure mobile and multi-platform environment with:

• Primary client: Android (enterprise-hardened builds); primary device class foldable smartphones with biometric hardware support.
• Additional clients: iOS (last three generations: iOS 15, 16, 17) and Web Dapp (Desktop/Laptop, including touch devices); same backend API contract.
• Deployment Model: Government-furnished or government-approved devices under MDM/UEM control where applicable; Web Dapp served over HTTPS with CORS.
• Connectivity: Online, offline, and degraded modes; backend supports all clients via REST and configurable CORS.

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Architecture Principles

Security First

• Multi-factor authentication required
• Hardware-backed encryption
• Zero-trust architecture principles
• Defense in depth

Resilience

• Offline operation capability
• Degraded mode support
• Data synchronization
• Automatic recovery

Compliance

• Standards-based implementation
• Compliance by design
• Audit trail throughout
• Certification ready

Modularity

• Modular architecture
• Clear module boundaries
• Well-defined interfaces
• Reusable components

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High-Level Architecture

System Components

┌─────────────────────────────────────────────────────────────┐
│                    SMOA Application                          │
├─────────────────────────────────────────────────────────────┤
│                                                               │
│  ┌──────────────┐  ┌──────────────┐  ┌──────────────┐       │
│  │   Core       │  │   Core       │  │   Core       │       │
│  │   Modules    │  │   Modules    │  │   Modules    │       │
│  │   (8)        │  │   (8)        │  │   (8)        │       │
│  └──────────────┘  └──────────────┘  └──────────────┘       │
│                                                               │
│  ┌──────────────┐  ┌──────────────┐  ┌──────────────┐       │
│  │   Feature    │  │   Feature    │  │   Feature    │       │
│  │   Modules    │  │   Modules    │  │   Modules    │       │
│  │   (13)       │  │   (13)       │  │   (13)       │       │
│  └──────────────┘  └──────────────┘  └──────────────┘       │
│                                                               │
│  ┌──────────────────────────────────────────────────────┐  │
│  │         Common Infrastructure                         │  │
│  │  - Authentication  - Security  - Database            │  │
│  │  - Networking     - Storage   - Logging             │  │
│  └──────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────┘

Core Modules (8)

1. core:auth - Authentication framework
2. core:security - Security infrastructure
3. core:common - Common utilities
4. core:barcode - PDF417 barcode generation
5. core:as4 - AS4 gateway messaging
6. core:eidas - eIDAS compliance
7. core:signing - Digital signatures & seals
8. core:certificates - Certificate management

Feature Modules (13)

1. modules:credentials - Issued credentials
2. modules:directory - Internal directory
3. modules:communications - Unit communications
4. modules:meetings - Secure meetings
5. modules:browser - Controlled browser
6. modules:orders - Orders management
7. modules:evidence - Evidence chain of custody
8. modules:reports - Report generation
9. modules:atf - ATF form support
10. modules:ncic - NCIC/III integration
11. modules:military - Military operations
12. modules:judicial - Judicial operations
13. modules:intelligence - Intelligence operations

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Component Architecture

Authentication Component

• Multi-factor authentication (PIN + Fingerprint + Facial Recognition)
• Session management
• Re-authentication triggers
• Hardware-backed key storage

Security Component

• Encryption (at rest and in transit)
• Key management
• Certificate management
• Audit logging
• Policy enforcement

Data Storage Component

• Room database (local SQLite)
• Encrypted storage
• Offline data caching
• Data synchronization

Network Component

• Secure communication (TLS)
• VPN support
• Offline mode detection
• Degraded mode handling

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Module Architecture

Module Structure

Each module follows a consistent structure:

• Domain Layer: Business logic and data models
• Data Layer: Database and repositories
• Presentation Layer: UI components (Jetpack Compose)
• Service Layer: Business services

Module Dependencies

• Core modules have no dependencies on feature modules
• Feature modules depend on core modules
• Clear dependency hierarchy
• Minimal inter-module dependencies

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Data Architecture

Data Model

• Room Database: Primary local storage
• Encrypted Storage: Sensitive data encryption
• Offline Cache: Time-bounded offline data
• Synchronization: Data sync on connectivity

Data Flow

1. User input → Domain layer
2. Domain layer → Data layer (persistence)
3. Data layer → Domain layer (retrieval)
4. Domain layer → Presentation layer (display)

Data Protection

• Encryption at rest (hardware-backed)
• Encryption in transit (TLS)
• Access control (RBAC)
• Audit logging

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Integration Architecture

External System Integrations

• AS4 Gateway: Inter-agency messaging
• NCIC/III: Law enforcement databases
• ATF eTrace: Firearms tracing
• QTSP: Qualified Trust Service Providers
• Timestamping Authority: Qualified timestamps

Integration Patterns

• RESTful APIs
• AS4 messaging
• Secure file transfer
• Certificate-based authentication

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Deployment Architecture

Deployment Model

• Device: Government-furnished foldable Android devices
• MDM/UEM: Mobile device management
• Backend Services: Enterprise backend (if applicable)
• Network: Secure government networks

Infrastructure Requirements

• Android 7.0+ (API 24+)
• Biometric hardware support
• Hardware-backed key storage
• Network connectivity (with offline support)

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Technology Stack

Platform

• Language: Kotlin
• Platform: Android
• Minimum SDK: 24 (Android 7.0)
• Target SDK: 34 (Android 14)

Core Libraries

• UI: Jetpack Compose
• Database: Room
• Networking: Retrofit, OkHttp
• Dependency Injection: Hilt
• Security: Android Keystore, BouncyCastle
• Barcode: ZXing
• PDF: PDFBox or iText

Development Tools

• IDE: Android Studio
• Build System: Gradle
• Version Control: Git
• CI/CD: (To be determined)

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Security Architecture

See Security Architecture Document for detailed security architecture.

Key Security Features

• Multi-factor authentication
• Hardware-backed encryption
• Secure key storage
• Encrypted communication
• Audit logging
• Policy enforcement

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Performance Considerations

Optimization Strategies

• Lazy loading
• Caching
• Background processing
• Efficient database queries
• Image optimization

Performance Targets

• Application startup: < 3 seconds
• Screen transitions: < 300ms
• API response: < 2 seconds
• Database queries: < 100ms

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Scalability

Current Scope

• Single device deployment
• Local data storage
• Offline-first architecture

Future Considerations

• Multi-device synchronization
• Cloud backend integration
• Enterprise deployment

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Diagrams

System Architecture Diagram

[To be added: PlantUML or image]

Component Architecture Diagram

[To be added: PlantUML or image]

Module Dependency Diagram

[To be added: PlantUML or image]

Data Flow Diagram

[To be added: PlantUML or image]

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References

• Specification
• Security Architecture
• Implementation Status
• Compliance Matrix

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Document Owner: Technical Lead
Last Updated: 2024-12-20
Status: Draft - In Progress
Next Review: 2024-12-27