Threema is a Swiss encrypted messaging application. It has more than 10 million users and more than 7000 on-premise customers. Prominent users of Threema include the Swiss Government and the Swiss Army, as well as the current Chancellor of Germany, Olaf Scholz. Threema has been widely advertised as a secure alternative to other messengers. In our work, we present seven attacks against the cryptographic protocols used by Threema, in three distinct threat models. All the attacks are accompanied by proof-of-concept implementations that demonstrate their feasibility in practice.

We examined the password policies of 120 of the most popular English-language websites in the world.

Man-in-the-Middle (MitM), one of the best known attacks in the world of computer security, is among the greatest concerns for professionals in the field. Main goal of MitM is to compromise confidentiality, integrity and availability of data flowing between source and destination. However, most of its many variants involve difficulties that make it not always possible. The present paper aims at modelling and describing a new method of attack, named Browser-in-the-Middle (BitM) which, despite the similarities with MitM in the way it controls the data flow between a client and the service it accesses, bypasses some of MitM’s typical shortcomings. It could be started by phishing techniques and in some cases coupled to the well-known Man-in-the-Browser (MitB) attack. It will be seen how BitM expands the range of the possible attacker’s actions, at the same time making them easier to implement. Among its features, the absence of the need to install malware of any kind on the victim’s machine and the total control it allows the attacker are to be emphasized. [Document PDF](https://link.springer.com/content/pdf/10.1007/s10207-021-00548-5.pdf)

We examined the password policies of 120 of the most popular English-language websites in the world.