COVIDSafe captures close contacts with the new Herald Protocol

30 November 2020

Even though we have made a range of significant improvements to COVIDSafe, we continue to look for ways we can improve the app further. Herald, a Bluetooth communication and range finding protocol that supports contact tracing, is one such improvement.

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The Australian Government’s response to the COVID-19 pandemic has focused on protecting the health of citizens and the economic wellbeing of the nation. As part of this, Australia was an early mover in implementing COVIDSafe as a digital contact tracing app that puts contact tracers and health authorities at the centre of our pandemic response.  COVIDSafe will become an even more important tool as COVID-19 restrictions ease across Australia and people move around more.

COVIDSafe was launched on 26 April and since then we have delivered 14 updates, including improvements in Bluetooth performance, privacy and security. The Australian technology community’s feedback has been pivotal to the app’s development. These contributions have directly driven important COVIDSafe performance enhancements that have benefited all users.

We will be giving the tech community the opportunity to review the source code and provide feedback on the new Herald Protocol, ahead of it being released.

An explanation of Herald

The Herald Protocol employs several techniques to improve Bluetooth communication across a wide range of mobile devices. This provides contact tracing apps with regular and accurate proximity information that helps make them highly effective, as the updated Bluetooth Encounter Logging results below demonstrate.

Herald is a VMware-originated open source project. It is part of VMware’s ongoing contribution towards the Linux Foundation Public Health initiative. The initiative aims to use open source technologies to help public health authorities across the world combat COVID-19.

The Herald website provides further information, including Detailed technical documentation and a design guide that outlines how Herald has been built.

Incorporating Herald into COVIDSafe

Incorporating Herald will further improve COVIDSafe’s performance, particularly when the app is running in the background on iOS devices.

Herald has been designed to provide the same level of Android and iOS backward compatibility as COVIDSafe currently does. This ensures COVIDSafe will continue to be available across the wide range of mobile devices used by the Australian community.

It will also support the current COVIDSafe operating model, which has been designed and optimised to meet Australia’s contact tracing needs, ensuring Health Officials are at the core of our response efforts. It is important that any digital contact tracing solution assists Australian health officials to manage the pandemic using our world-leading contact tracing processes.

The Herald difference

Testing of Herald in COVIDSafe has demonstrated a near 100% detection of close contacts in the foreground and background across iOS and Android devices. It will give COVIDSafe an ‘excellent’ rating for encounter detection on iPhone to iPhone, and iPhone to Android digital handshakes.

Our testing results showed:

  • increased Bluetooth performance, even in background, leading to more encounters being captured between devices, especially between iOS devices
  • no substantial change in battery usage when compared to current COVIDSafe – on average 1 to 3 per cent per hour, depending on the age of the phone and its battery capacity.

Further details on COVIDSafe’s Bluetooth performance improvements and battery performance are provided below.

Rigorous analysis and testing by cyber security experts has shown that the Herald-enabled COVIDSafe app continues to provide users with world leading privacy and security protection.

Please note: Some incorrect reports say that the new Herald Bluetooth Protocol for COVIDSafe is the same protocol that the UK NHS abandoned earlier this year. This is false, as it is not the same protocol. Herald has been developed and open sourced as part of the Linux Foundation Public Health initiative in July 2020. As Herald is an open source technology that is available at no cost, the implementation of Herald will be covered from existing COVIDSafe resources.

Call to the Australian Tech Community: Improve COVIDSafe and other contact tracing apps

Australia will be the first country in the world to implement the Herald protocol.

We value this opportunity for your feedback and suggestions to help us, and other countries that may adopt Herald, to build stronger contact tracing apps that best meet their country specific contact tracing needs.

We welcome your feedback on the pre-release Herald-integrated COVIDSafe source code directly in the GitHub repository for iOS or for Android or through security@covidsafe.gov.au. We are engaging as early as possible with the technology community to seek your valuable feedback on the code. We are still testing the pre-release code so in some cases it includes logging code that will be removed prior to launch. 

We will review all feedback and where appropriate, add it to our backlog for prioritisation in a COVIDSafe update. We’ve shown our commitment to working with the technology community as we’ve developed COVIDSafe so far and we’d appreciate your patience as we work through feedback on the Herald protocol. We value your feedback and it’s an important part of making sure we continue to have a world-leading contact tracing system.

COVIDSafe Bluetooth Encounter Logging Results

COVIDSafe Bluetooth performance summary results with Herald

27 November 2020

Android to Android

Android to iOS

iOS to iOS

Active -> Active

Excellent

Excellent

Excellent

Active -> Background Unlocked

Excellent

Excellent

Excellent

Active -> Locked

Excellent

Excellent

Excellent

Locked -> Locked

Excellent

Excellent

Excellent

Encounter logging: Excellent (80% to 100%), Good (50% to 80%), Moderate (25% to 50%), Poor (25% or below). Shaded cells show areas of improvement compared to previous test results.

COVIDSafe Bluetooth performance summary results prior to Herald 

1 August 2020

Android to Android

Android to iOS

iOS to iOS

Active -> Active

Excellent

Excellent

Excellent

Active -> Background Unlocked

Excellent

Good

Excellent

Active -> Locked

Excellent

Good

Good

Locked -> Locked

Excellent

Good

Moderate

 

26 May 2020

Android to Android

Android to iOS

iOS to iOS

Active -> Active

Excellent

Excellent

Excellent

Active -> Background Unlocked

Excellent

Good

Excellent

Active -> Locked

Excellent

Moderate

Good

Locked -> Locked

Excellent

Moderate

Moderate

 

13 May 2020

Android to Android

Android to iOS

iOS to iOS

Active -> Active

Excellent

Excellent

Excellent

Active -> Background Unlocked

Excellent

Good

Excellent

Active -> Locked

Excellent

Moderate

Moderate

Locked -> Locked

Excellent

Moderate

Moderate

 

26 April 2020

Android to Android

Android to iOS

iOS to iOS

Active -> Active

Excellent

Excellent

Excellent

Active -> Background Unlocked

Excellent

Good

Good

Active -> Locked

Excellent

Poor

Moderate

Locked -> Locked

Good

Poor

Poor

Encounter logging: Excellent (80% to 100%), Good (50% to 80%), Moderate (25% to 50%), Poor (25% or below).

COVIDSafe Battery Usage Results

Battery usage tests were conducted using six devices. Results found that a device running Herald uses between 1.3% and 3.2% of battery power per hour. The exact number varies on each device, depending on the age of the phone model, age of the phone, and its battery capacity.

The tests below were performed on devices that only had the Herald-enabled COVIDSafe app installed.

COVIDSafe Herald-integrated battery usage summary results

 

1 hour

8 hours

12 hours

Samsung J6

1.3%

10.2%

15.3%

iPhone 6 Plus

1.6%

12.9%

19.4%

Samsung A20

1.7%

13.4%

20.2%

Samsung A5

2.0%

16.1%

24.2%

Google Pixel 2

2.8%

22.0%

33.1%

iPhone 6S

3.2%

25.8%

38.7%

The measurements reflect the total battery use for running both the device’s operating system and the Herald-enabled COVIDSafe app on each device.

Visit the COVIDSafe website for more information or to access the application source code.

For media enquiries email us at media@dta.gov.au

For other enquiries email us at info@dta.gov.au