Why Families Need Threat Models

At work, you wouldn't ship a feature without considering the security implications. At home, you've probably never formally considered the security implications of your family's digital life — even though the assets at stake (identity, finances, children's safety) are arguably more important.

The Family Security Paradox

Engineers often have a paradoxical relationship with home security:

At Work:                          At Home:
✅ Threat models every service    ❌ No threat model for family tech
✅ Principle of least privilege    ❌ Kids have admin on their devices
✅ Incident response playbooks    ❌ No plan for identity theft
✅ Regular security reviews        ❌ "I'll get to it eventually"
✅ Defense in depth               ❌ Single password for everything

The reason is obvious: at work, there's a team, a process, and accountability. At home, it's just you, and "secure the family" is an overwhelming, unstructured task.

Threat modeling provides the structure.

What a Family Threat Model Covers

Unlike enterprise threat models that focus on specific applications, a family threat model covers your entire digital ecosystem:

┌─────────────────────────────────────────────────┐
│              FAMILY DIGITAL ECOSYSTEM            │
│                                                 │
│  People:           Assets:          Infrastructure:
│  ├── You           ├── Financial    ├── Home network
│  ├── Partner       │   accounts     ├── WiFi / DNS
│  ├── Teen (15)     ├── Identity     ├── Cloud accounts
│  ├── Child (10)    │   documents    ├── Devices
│  └── Elderly       ├── Photos/      ├── Smart home
│      parent        │   memories     ├── Vehicles
│                    ├── Medical      └── Mail
│                    │   records
│                    ├── Children's
│                    │   data
│                    └── Professional
│                        reputation
└─────────────────────────────────────────────────┘

The Threat Modeling Process

1. IDENTIFY ASSETS — What are we protecting?
2. IDENTIFY ADVERSARIES — Who might attack us?
3. MAP DATA FLOWS — How does data move through our systems?
4. APPLY STRIDE — What threats exist at each point?
5. ASSESS RISK — Which threats are most likely and impactful?
6. DEFINE MITIGATIONS — What do we do about them?
7. REVIEW REGULARLY — Is our model still accurate?

This is the same process used for enterprise applications, adapted for the home context. The key difference: at home, the "users" are your family members with varying technical sophistication, and the "SLA" is "don't lose our life savings or compromise our kids' safety."

Getting Started

You don't need fancy tools. Start with a markdown document:

# Family Threat Model
## Last Updated: 2026-03-16

### Family Members
| Name | Role | Tech Level | Primary Devices | Key Accounts |
|------|------|-----------|----------------|---------------|
| You | Admin | Expert | MacBook, iPhone | All |
| Partner | User | Moderate | Laptop, iPhone | Email, banking, social |
| Teen | User | High (for age) | iPad, Chromebook | School, social, gaming |
| Child | Limited user | Low | iPad (managed) | School only |

### Critical Assets (ranked)
1. Family identity documents / SSNs
2. Financial accounts
3. Primary email accounts (recovery for everything)
4. Children's data and online safety
5. Medical records
6. Photos / memories (irreplaceable)

This document becomes the foundation for every security decision you make for your family.