We’ve been thinking a lot about contact tracing apps in recent weeks. There are ongoing debates about whether a centralised or decentralised model is superior, and how the ensuing discussions around privacy will impact their takeup.
When the NHSX contact tracing app was made available in the app stores last Thursday we decided to take a quick look at its operation and how the code has been put together. We used the Android version and the excellent MobSF tools to do our reversing analysis. On Friday the full source code of the app was also published on github.
More details of the UK's controversial NHSX contact tracing app are being released as the app starts a wider scale trial on the Isle of Wight this week. NHSX is a digital transformation group associated with the UK National Health Service.
Why controversial? There are many reasons, some to do with how the app development was initially procured, but also specifically from a technical perspective as the UK has opted for a centralised contact tracing approach rather than the decentralised model being championed by Apple and Google amongst others (including ourselves).
Google announced Android App Bundles a couple of years ago at I/O 2018. App Bundles are a new app publishing format providing new features that have rapidly driven their adoption. In particular App Bundle delivery enables automatic splitting of various assets within the overall app package, so they are only delivered to a device if they are actually needed.
Approov lets your mobile app prove to a backend API that it really is the official mobile app making the call, and that it is not running in an environment that may be compromised. Only requests from the apps that you specifically allow can make successful requests.
Our aim is to make the process of integrating Approov into your mobile app as simple as possible. Our Quickstart guides show you how to Approov into your app, tailored to whatever framework or programming style you’ve already adopted. In this blog we are going to cover the comprehensive options we have for Android Native app development.
The Android app store contains numerous Cloner Apps. These are an increasingly popular category that allow you to have multiple accounts associated with an app, such as a social media or messaging app. Our analysis shows that such apps introduce some really concerning potential security isolation risks that you should be aware of so that you can decide if you want to enable features to block the use of such cloner apps with your own app.
Last Friday, there was an unusual joint announcement from Apple and Google providing details of a new phone API for Covid-19 contact tracing via Bluetooth. The protocol allows mobile phones to continually transmit Bluetooth advertisements to one another. This includes a proximity identifier derived from randomly generated keys that can be held secretly on each device. If a phone user is later diagnosed with Covid-19, they are able to upload the daily tracing keys for those days when they might have been infectious.