Investigating a proprietary Android 2FA system

This article concerns an Android app used as part of a proprietary two-factor authentication (2FA) system. Investigation of the app and 2FA protocol reveals some interesting design decisions.

Overview

The 2FA system is similar to well-known offerings such as Duo Security and Okta Verify.… »

Investigating a historical Android anti-root protection system

This article concerns a specialised Android app used as part of a proprietary authentication protocol, developed in the late 2010s. Given the intended use case, the app features a number of aggressive security measures – the app uses FLAG_SECURE and does not run when developer… »

GIMP 3.0 plug-in for exporting JBIG2-encoded PDF files

JBIG2 is an efficient image compression format for bi-level (bi-tonal) images, which is supported by the PDF file format and common PDF viewers, but which lacks widely available tooling for its generation. GIMP is an open-source image editing suite, which has the capacity to output… »

Australian English communication growth charts

Below are presented expressive vocabulary ‘growth charts’ and limit ages, for an Australian English cohort, based on the norming samples for the long-form Australian English Communicative Development Inventory (OZI),^1,2 and its short form (OZI-SF).^3,4

Neonatal jaundice treatment thresholds calculator (NICE guidelines)

I present a free open source webapp for calculating neonatal jaundice treatment thresholds (bilirubin ‘nomograms’) based on UK National Institute for Health and Care Excellence (NICE) guidelines. The calculator can be accessed at https://yingtongli.me/bili/.

Please note that the calculator is based on the 2010… »

End of the line for Virtual Metro

Today I am regrettably discontinuing Virtual Metro. I launched this fun little project in 2019 and, according to server logs, it appears to have enjoyed modest success since then. Unfortunately, it has been down since at least March this year and perhaps earlier, and… »