Contact tracing is the prime strategy to combat COVID-19.

Optimising quarantine yields requires better data collection processes. This can be achieved through verification and automation of the contact tracing process.

A motivating example is China's HealthCode solution.

Singapore context

Singapore intends to open it's economy phase by phase, starting with the essentials.

Solution outline

We propose a verification technique for building entry and a fast contact tracing solution.

Current measures

SafeEntry helps to restrict and monitor access to areas. It is designed to be easy to deploy and collect citizen access behaviour. Verification process in SafeEntry is manual with no real-time verification. SafeEntry

Tracetogether helps to track user-to-user interactions and generates a temporary ID for each device to preserve privacy while using bluetooth as a means of transferring data to reduce user data use. In the tracetogether app, A user is assigned a unique random ID by the app and collects data for contact tracing by turning on Bluetooth. Pseudoanonymous ID generated by the app protects user identity but there is no common basis for information sharing. Below we show userflow of TraceTogether app. TraceTogether

Prototype explained

The code for Prototype is open sourced on Github. Please see

DID simplifies information accessibility, standardise tracing, and satisfy user privacy demands.

Step 1 : Employer signs a JSON file containing workerDID and companyOwnerDID using the employer's private key and gives authorisation to the workerDID linked to the company

Step 2: When the worker wants to enter the building for work, the authorization JSON file is showed and verified.

Step 3a: If authorization fails, the app will prompt the access controller.

Step 3b: If authorization succeeds, the app prompts that "Verified and Successfully entered".

Step 3c: If the worker enters a building twice, the app prompts that "You have already entered the building".

Step 4: We can conduct contact tracing quickly if the worker is infected by checking all entries to the building by time.

Next Steps

On the advice of the team that built GovTech's OpenCerts due to their blockchain experience, we suggest the next step to be to build a prototype with key features that impact user adoption such as an app.

We suggest looking into building a DID solution for a prototype roll out within a controlled environment such as Universities.

The current prototype simulates a DID, however we should implement one that follows the w3c standard DID.

Presentation materials

Slides for web viewing:

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