# SMOA Threat Model

**Version:** 1.0  
**Last Updated:** 2024-12-20  
**Status:** Draft - In Progress  
**Classification:** Internal Use

---

## Threat Model Overview

### Methodology
This threat model follows STRIDE methodology:
- **S**poofing
- **T**ampering
- **R**epudiation
- **I**nformation Disclosure
- **D**enial of Service
- **E**levation of Privilege

### System Boundaries
- **Application:** SMOA Android application
- **Device:** Foldable Android device
- **Network:** Secure government networks
- **Backend Services:** Enterprise backend services (if applicable)
- **External Systems:** AS4 gateway, NCIC, ATF, QTSP

### Trust Boundaries
- **Device Boundary:** Trust boundary between device and network
- **Application Boundary:** Trust boundary between application and OS
- **User Boundary:** Trust boundary between user and application
- **Network Boundary:** Trust boundary between device and backend

---

## Threat Identification

### Authentication Threats

#### T-AUTH-001: PIN Guessing
- **Threat:** Attacker guesses user PIN
- **Likelihood:** Medium
- **Impact:** High
- **Mitigation:**
  - PIN complexity requirements
  - Retry limits and lockout
  - Rate limiting
  - **Status:** ✅ Mitigated

#### T-AUTH-002: Biometric Spoofing
- **Threat:** Attacker spoofs biometric authentication
- **Likelihood:** Low
- **Impact:** High
- **Mitigation:**
  - Hardware-backed biometrics
  - Liveness detection
  - Anti-spoofing measures
  - **Status:** ✅ Mitigated

#### T-AUTH-003: Session Hijacking
- **Threat:** Attacker hijacks user session
- **Likelihood:** Low
- **Impact:** High
- **Mitigation:**
  - Secure session tokens
  - Session timeout
  - Re-authentication requirements
  - **Status:** ✅ Mitigated

### Authorization Threats

#### T-AUTHZ-001: Privilege Escalation
- **Threat:** Attacker gains unauthorized privileges
- **Likelihood:** Low
- **Impact:** High
- **Mitigation:**
  - Role-based access control
  - Principle of least privilege
  - Permission validation
  - **Status:** ✅ Mitigated

#### T-AUTHZ-002: Unauthorized Access
- **Threat:** Attacker accesses unauthorized data
- **Likelihood:** Medium
- **Impact:** High
- **Mitigation:**
  - Access control enforcement
  - Data classification
  - Audit logging
  - **Status:** ✅ Mitigated

### Data Protection Threats

#### T-DATA-001: Data Theft
- **Threat:** Attacker steals sensitive data
- **Likelihood:** Medium
- **Impact:** High
- **Mitigation:**
  - Encryption at rest
  - Encryption in transit
  - Access controls
  - **Status:** ✅ Mitigated

#### T-DATA-002: Data Tampering
- **Threat:** Attacker modifies data
- **Likelihood:** Low
- **Impact:** High
- **Mitigation:**
  - Data integrity checks
  - Digital signatures
  - Audit logging
  - **Status:** ✅ Mitigated

#### T-DATA-003: Data Leakage
- **Threat:** Sensitive data leaked
- **Likelihood:** Medium
- **Impact:** High
- **Mitigation:**
  - Data classification
  - Access controls
  - Monitoring
  - **Status:** ✅ Mitigated

### Network Threats

#### T-NET-001: Man-in-the-Middle
- **Threat:** Attacker intercepts network traffic
- **Likelihood:** Low
- **Impact:** High
- **Mitigation:**
  - TLS encryption
  - Certificate pinning
  - Mutual authentication
  - **Status:** ✅ Mitigated

#### T-NET-002: Network Eavesdropping
- **Threat:** Attacker eavesdrops on network traffic
- **Likelihood:** Low
- **Impact:** Medium
- **Mitigation:**
  - TLS encryption
  - VPN requirements
  - Network monitoring
  - **Status:** ✅ Mitigated

#### T-NET-003: Denial of Service
- **Threat:** Attacker causes service unavailability
- **Likelihood:** Low
- **Impact:** Medium
- **Mitigation:**
  - Offline operation capability
  - Rate limiting
  - Resource management
  - **Status:** ✅ Mitigated

### Device Threats

#### T-DEV-001: Device Theft
- **Threat:** Attacker steals device
- **Likelihood:** Medium
- **Impact:** High
- **Mitigation:**
  - Device encryption
  - Remote wipe capability
  - Strong authentication
  - **Status:** ✅ Mitigated

#### T-DEV-002: Device Compromise
- **Threat:** Attacker compromises device
- **Likelihood:** Low
- **Impact:** High
- **Mitigation:**
  - Device hardening
  - Security monitoring
  - Incident response
  - **Status:** ⚠️ Partial

#### T-DEV-003: Malicious Apps
- **Threat:** Malicious apps compromise security
- **Likelihood:** Low
- **Impact:** Medium
- **Mitigation:**
  - App isolation
  - Permission restrictions
  - Security scanning
  - **Status:** ✅ Mitigated

### Application Threats

#### T-APP-001: Code Injection
- **Threat:** Attacker injects malicious code
- **Likelihood:** Low
- **Impact:** High
- **Mitigation:**
  - Input validation
  - Secure coding practices
  - Code review
  - **Status:** ✅ Mitigated

#### T-APP-002: Reverse Engineering
- **Threat:** Attacker reverse engineers application
- **Likelihood:** Medium
- **Impact:** Medium
- **Mitigation:**
  - Code obfuscation
  - Anti-tampering measures
  - Secure key storage
  - **Status:** ⚠️ Partial

#### T-APP-003: Side-Channel Attacks
- **Threat:** Attacker uses side-channel information
- **Likelihood:** Low
- **Impact:** Medium
- **Mitigation:**
  - Constant-time operations
  - Secure memory handling
  - Timing attack protection
  - **Status:** ⚠️ Partial

---

## Threat Analysis

### Threat Likelihood Assessment

| Threat | Likelihood | Rationale |
|--------|------------|-----------|
| PIN Guessing | Medium | PINs can be guessed with sufficient attempts |
| Biometric Spoofing | Low | Hardware-backed biometrics with liveness detection |
| Session Hijacking | Low | Secure session management |
| Privilege Escalation | Low | Strong RBAC enforcement |
| Data Theft | Medium | Device theft is possible |
| Data Tampering | Low | Integrity checks and signatures |
| Man-in-the-Middle | Low | TLS and certificate pinning |
| Device Theft | Medium | Physical device theft possible |
| Code Injection | Low | Input validation and secure coding |
| Reverse Engineering | Medium | Application can be analyzed |

### Threat Impact Assessment

| Threat | Impact | Rationale |
|--------|--------|-----------|
| Authentication Bypass | High | Complete system compromise |
| Data Theft | High | Sensitive data exposure |
| Data Tampering | High | Data integrity compromise |
| Privilege Escalation | High | Unauthorized access |
| Network Interception | High | Communication compromise |
| Device Compromise | High | Complete device control |
| Service Disruption | Medium | Operational impact |

### Risk Assessment

| Threat | Likelihood | Impact | Risk Level | Priority |
|--------|------------|--------|-----------|----------|
| T-AUTH-001: PIN Guessing | Medium | High | High | P1 |
| T-AUTH-002: Biometric Spoofing | Low | High | Medium | P2 |
| T-AUTH-003: Session Hijacking | Low | High | Medium | P2 |
| T-AUTHZ-001: Privilege Escalation | Low | High | Medium | P1 |
| T-DATA-001: Data Theft | Medium | High | High | P1 |
| T-DATA-002: Data Tampering | Low | High | Medium | P1 |
| T-NET-001: Man-in-the-Middle | Low | High | Medium | P1 |
| T-DEV-001: Device Theft | Medium | High | High | P1 |
| T-APP-001: Code Injection | Low | High | Medium | P1 |

---

## Mitigation Strategies

### Authentication Mitigations
- ✅ Multi-factor authentication
- ✅ Hardware-backed biometrics
- ✅ PIN complexity and lockout
- ✅ Session management
- ✅ Re-authentication requirements

### Authorization Mitigations
- ✅ Role-based access control
- ✅ Principle of least privilege
- ✅ Permission validation
- ✅ Access control enforcement
- ✅ Audit logging

### Data Protection Mitigations
- ✅ Encryption at rest (AES-256-GCM)
- ✅ Encryption in transit (TLS 1.2+)
- ✅ Hardware-backed key storage
- ✅ Data integrity checks
- ✅ Digital signatures

### Network Mitigations
- ✅ TLS encryption
- ✅ Certificate pinning
- ✅ VPN requirements
- ✅ Network monitoring
- ✅ Rate limiting

### Device Mitigations
- ✅ Device encryption
- ✅ Remote wipe capability
- ✅ Device hardening
- ✅ Security monitoring
- ✅ MDM/UEM management

### Application Mitigations
- ✅ Input validation
- ✅ Secure coding practices
- ✅ Code review
- ✅ Vulnerability scanning
- ⚠️ Code obfuscation (partial)
- ⚠️ Anti-tampering (partial)

---

## Residual Risk

### High Residual Risk
- **Device Compromise:** Physical access to compromised device
- **Reverse Engineering:** Application analysis and key extraction
- **Side-Channel Attacks:** Timing and power analysis attacks

### Medium Residual Risk
- **PIN Guessing:** With sufficient time and access
- **Data Theft:** If device is stolen and authentication bypassed

### Low Residual Risk
- **Network Attacks:** With TLS and VPN protection
- **Code Injection:** With input validation
- **Session Hijacking:** With secure session management

---

## Threat Monitoring

### Detection Capabilities
- **Failed Authentication:** Monitor authentication failures
- **Unauthorized Access:** Monitor access attempts
- **Anomalous Behavior:** Detect unusual patterns
- **Security Violations:** Detect policy violations

### Response Procedures
- **Automated Response:** Automatic threat response
- **Alert Generation:** Security alert generation
- **Incident Escalation:** Escalation procedures
- **Remediation:** Threat remediation

---

## Threat Model Maintenance

### Review Schedule
- **Quarterly Reviews:** Review threat model quarterly
- **After Major Changes:** Review after architecture changes
- **After Security Incidents:** Review after security incidents
- **Before Certification:** Review before security certification

### Update Procedures
1. Identify new threats
2. Assess threat likelihood and impact
3. Update threat model
4. Review mitigations
5. Update documentation

---

## References

- [Security Architecture](SMOA-Security-Architecture.md)
- [Security Configuration Guide](SMOA-Security-Configuration-Guide.md)
- [Incident Response Plan](SMOA-Incident-Response-Plan.md)
- [Architecture Documentation](../architecture/ARCHITECTURE.md)

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**Document Owner:** Security Architect  
**Last Updated:** 2024-12-20  
**Status:** Draft - In Progress  
**Classification:** Internal Use  
**Next Review:** 2024-12-27