Mattermost End-to-End Encryption Plugin

This blog post introduces a plugin that provides end-to-end encryption (E2EE) to Mattermost.

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Audit of Session Secure Messaging Application

Oxen mandated Quarkslab to perform an audit of their instant messaging solution Session . This application, forked from Signal, aims to improve users privacy by using an onion routing mechanism . This mechanism differs from Tor's one by requiring a deposit in their own cryptocurrency to operate a Service Node (Snode ), the Oxen equivalent of a Tor Entry, Relay or Exit Node. While reviewing the architecture of this solution, we found some issues and provided recommendations to improve parts of the implementations.

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Make Confide great again? No, we cannot

In recent weeks, Confide, a secure instant messaging application, has gained popularity in some circles. This article presents a quick assessment of the security of this application. The official website boasts the confidentiality provided by the product through three qualifiers: encrypted, ephemeral and screenshot protected. Each of these aspects will be studied.

The encryption protocol will be particularly detailed because it is tagged as battle tested, military grade cryptography. We already knew about military grade cryptography, which seems to be a synonym of put AES-256 somewhere, no matter how you use it in many applications, but we had never heard of battle tested cryptography. This article is an opportunity to present this technology.

Developing properly end-to-end communication systems is complex. As we have seen in the past with iMessage, even if cryptographic primitives are correctly implemented and encryption keys are correctly generated and protected, the design is critical to forbid the service operator from being able to eavesdrop messages.

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A brief survey of Fully Homomorphic Encryption, computing on encrypted data

When appointing computation of private data to a third party, privacy is an issue. How can one delegate computation without giving up one's secrets? This gets trickier when multiple parties are involved. Several works on Multi-Party Computation (MPC) addressed this issue, but a new approach has started to emerge: Fully Homomorphic Encryption (FHE).

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Security assessment of instant messaging app ChatSecure: when privacy matters

In 2014, QuarksLab was missioned by OpenITP to audit the iOS application ChatSecure and to identify any weakness that could lead to information leakage or any other risk that could impact the user.

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iMessage Privacy

iMessage is probably one of the most trendy instant messaging systems. Apple presents it as very secure, with high cryptographic standards, including end-to-end encryption preventing even Apple from reading the messages. Is this true?

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