Question:
Isn't it much more private if everyone just log their locations via mobile apps directly into their own private devices (say mobile phones or home servers) without going though Community Processing at all ?
Basically, people run a tracking app on their mobile phones which stores their movements on their phone or send the movements back to their own server at home. No one else will have access to their locations then.
The government would then broadcast the locations of the positive people, which everyone can then download and compare with their own stored movements.
Answer:
Totally private systems (where no one else except the owner can see the data) makes the determination of whether a close contact incident very inefficient.
1. Privacy of Positive Cases
To make the matching fast and accurate, people who are positive will need to have ALL their movements during a period downloaded into millions of strangers' private servers.
This is not acceptable to people who are tested positive.
2. High Resource Consumption
Since there is no way of telling before hand who was near the positive person, the movements of the positive person have to be broadcasted to EVERYONE in the country even if they are thousands of kilometers away.
This is a big drain on computing and network resources of everyone.
3. Reliability of Private Devices
Since presence records are coming in real-time all through the day, high quality internet and redundant server is required to prevent losing data. This is beyond the capability of standard NBN and home servers, making direct logging to home servers expensive.
For mobile phones, the need to constantly download the movements
4. Our Data Sharing
With our system's block based design, there is privacy for ALL - whether a person is positive or not.
With our system:
- ONLY potentially exposed people (people within the same block) are notified (not everyone).
- ONLY blocks (e.g. bounded within 30 minutes and 100 metres), NOT exact times/locations are disclosed potentially exposed people.
- Before and After blocks outside the encounter period are NOT disclosed.
5. Our Personal Servers
Our system can make use of low cost personal servers running at home, but only as long term storage for analysis of data.
The real-time data collection is performed by Community Processing modules running in full redundant manner across multiple professionally data centres with high quality internet connection.