About This Calculator
How easily can you be re-identified from "anonymous" data? Even without your name or address, a few basic characteristics can single you out.
🎯 How It Works
We use real Australian Bureau of Statistics (ABS) census data to count how many people share your exact combination of:
- 📍 Postcode
- 🎂 Age group
- ⚧️ Gender
- 💼 Occupation (optional)
The key insight: The fewer people who match your profile, the easier it is to identify you—even in datasets that have removed names.
🚨 Understanding Your Risk
Very High Risk: Less than 10 people match → You may be easily identified
High Risk: 10-99 people → One or two extra data points may identify you
Moderate Risk: 100-999 people → Some protection, but linkable
Lower Risk: 1,000+ people → Better anonymity in this group
⚠️ Why This Matters
Many organizations share "de-identified" data thinking it's safe. But research shows:
- 🔗 Combinations are unique - Common attributes become identifying when combined
- 🔍 Data linkage is easy - Multiple datasets can be cross-referenced
- 📊 More data = More risk - Each additional attribute exponentially increases re-identification
🔒 Your Privacy
✅ All calculations happen in your browser
✅ We never collect, store, or transmit your data
✅ No cookies, no tracking, no analytics
✅ Open source - View the code on GitHub
📚 Data & Accuracy
This tool uses real ABS census data. The ABS applies confidentiality protections including random adjustments to cell values to protect privacy. This means:
- Small population counts are less precise
- The same query may produce slightly different results
- Our risk calculations are estimates for educational purposes
💡 Learn More
- 🇦🇺 Office of the Australian Information Commissioner
- 📖 Australian Privacy Principles
- 🌍 Original research from Imperial College London