Two of the world's largest technology companies are coming together to help combat the coronavirus.
Apple and Google have announced a partnership on contact tracing technology.
It will involve the use of Bluetooth to help governments and health agencies reduce the spread of the virus.
They say that user privacy and security are "central" to the design.
The two companies - whose operating systems power 99% of the world's smartphones - plan to add new software to devices to make it easier to track down people who may have been infected.
To be effective, the system would require millions of people to opt into the system and trust the technology giants' safeguards.
Under the plan, smartphones with the contact tracing technology will emit unique Bluetooth signals.
Phones within about 6ft can then record anonymous information about their encounters.
People who test positive for the virus can opt to send an encrypted list of phones they came near to Apple and Google, which will trigger alerts to potentially exposed users to seek more information.
Public health authorities would need to confirm that a person has tested positive for COVID-19 before they can send on the data.
The logs will be scrambled to keep infected individuals' data anonymous - even to Apple, Google and contact tracing app makers, the two companies said.
They added that their contact tracing system will not track GPS location.
In a statement Apple and Google say this will be done in two steps, starting in May.
"Since COVID-19 can be transmitted through close proximity to affected individuals, public health officials have identified contact tracing as a valuable tool to help contain its spread.
"A number of leading public health authorities, universities, and NGOs around the world have been doing important work to develop opt-in contact tracing technology.
"To further this cause, Apple and Google will be launching a comprehensive solution that includes application programming interfaces (APIs) and operating system-level technology to assist in enabling contact tracing.
"Given the urgent need, the plan is to implement this solution in two steps while maintaining strong protections around user privacy."
First, both companies will release APIs that enable interoperability between Android and iOS devices using apps from public health authorities.
These official apps will be available for users to download from their respective app stores.
And in the coming months, Apple and Google will work to enable a broader Bluetooth-based contact tracing platform - by building this functionality into the underlying platforms.
This is a more robust solution and would allow more people to participate, if they choose to opt in.
Apple and Google add that privacy, transparency and consent are "of utmost importance in this effort".
They says they will "openly publish information about our work for others to analyze."
"All of us at Apple and Google believe there has never been a more important moment to work together to solve one of the world’s most pressing problems.
"Through close cooperation and collaboration with developers, governments and public health providers, we hope to harness the power of technology to help countries around the world slow the spread of COVID-19 and accelerate the return of everyday life."
Apple will distribute the technology as an update to its iPhone operating system.
Google said the tools and updates would not be available where its services are blocked, such as in China or on unofficial Android devices.
Additional reporting: IRN