A comprehensive analysis of the cryptographic protocols used in the Swiss encrypted messaging application Threema has revealed a number of loopholes that could be exploited to break authentication protections and even recover users’ private keys.
The seven attacks span three different threat models, according to ETH Zurich researchers Kenneth G. Paterson, Matteo Scarlata, and Kien Tuong Truong, who reported the issues to Threema on October 3, 2022. The weaknesses have since been addressed as part of updates released by the company on November 29, 2022.
Threema is an encrypted messaging app that’s used by more than 11 million users as of October 2022. “Security and privacy are deeply ingrained in Threema’s DNA,” the company claims on its website.
Officially used by the Swiss Government and the Swiss Army, it’s also advertised as a secure alternative alongside other services such as Signal, Meta-owned WhatsApp, and Telegram.
While Threema has been subjected to third-party code audits at least twice – once in 2019 and a second time in 2020 – the latest findings show that they weren’t thorough enough to uncover the problems present in the “cryptographic core of the application.”
images from Hacker News