Contact Tracing

BlueTrace used in a crowd

What is BlueTrace?

Contact tracing is an important tool to reduce the spread of infectious diseases like COVID-19. BlueTrace is a privacy-preserving protocol for community-driven contact tracing using Bluetooth devices, that allows for global inter-operability.

BlueTrace is designed for decentralised proximity logging and supplements centralised contact tracing by public health authorities. Proximity logging using Bluetooth addresses a key limitation of manual contact tracing: that it is dependent on a person’s memory and is therefore limited to contacts that a person is acquainted with and remembers having met. BlueTrace therefore enables contact tracing to be more scalable and less resource-intensive.

Find out more about BlueTrace by reading the white paper

Read the BlueTrace manifesto

BlueTrace is designed around privacy


Third-parties cannot use BlueTrace communications to track users over time

A device’s temporary identifier rotates frequently, preventing malicious actors from tracking individual users over time by sniffing for BlueTrace messages.


Limited collection of personally-identifiable information

The only personally-identifiable information collected is a phone number, which is securely stored by the health authority.


Local storage of encounter history

Each user’s encounter history is stored exclusively on their own device. The health authority only has access to this history when an infected person chooses to share it.


Revocable consent

Users have control of their personal data. When they withdraw consent, all personally-identifiable data stored at the health authority is deleted. All encounter history will thus cease to be linked to the user.

BlueTrace protocol can be implemented using the OpenTrace code. TraceTogether was launched in Singapore on 20 March 2020. It is the first national Bluetooth contact tracing app in the world, and uses the OpenTrace code to implement the BlueTrace protocol.