In this article I describe my two-months summer internship project at Quarkslab: obfuscating Java bytecode using the [Epona] Code Obfuscator. This article explains our approach, its advantages and limitations.

The Tari Labs mandated Quarkslab to perform a cryptographic and security assessment of the dalek libraries. One of the Tari Labs' projects is to implement the Tari protocol, a decentralised assets protocol. It relies on some of the dalek libraries, especially the cryptographic primitives, provided by subtle and curve25519-dalek. Moreover, the use of Bulletproofs , and its implementation by the authors of the dalek libraries, will allow them to enable efficient confidential transactions on the blockchain in a near future.

We only found some minor issues. We also provided recommendations on the usage of the libraries and third-party libraries.

Quarkslab's team performed a cryptographic and security assessment of the Monero Research Lab’s new Proof-of-Work algorithm, called RandomX . RandomX is a proof-of-work algorithm that is optimized for general-purpose CPUs. RandomX uses random code execution together with several memory-hard techniques to minimize the efficiency advantage of specialized hardware. We only found minor inconsistencies and formulated a few recommendations. These recommendations are mainly relevant when using alternative configurations but they are of less importance with the current configuration and usage of RandomX. The full report of the assessment can be found at the following address:

On September 2018, FreeBSD published the security advisory FreeBSD-SA-18:12, fixing a kernel memory disclosure vulnerability affecting all the supported versions of this operating system.

Quarkslab's team performed a cryptographic and security assessment of both the Bulletproof and MLSAG protocols in Particl. Bulletproof is a non-interactive zero-knowledge proof protocol, while MLSAG is a new ring signature protocol. Both are to be used in cryptocurrency transactions to ensure that they do not leak the amount exchanged or the exact identity of the buyers. Both implementations were found sound and conform to their respective reference papers [BBBPWM18] [SN15]. The full report of the assessment can be found at the following address:

This is the second of two blog posts about macOS kernel debugging. In the previous post, we defined most of the terminology used in both articles, described how kernel debugging is implemented for the macOS kernel and discussed the limitations of the available tools; here, we present LLDBagility, our solution for an easier and more functional macOS debugging experience.

This blog post deals with QBDI and how it can be used to reverse an Android JNI library

This blog post is about detecting modifications between genuine and repackaged applications.

This is the first of two blog posts about macOS kernel debugging. Here, we introduce what kernel debugging is, explain how it is implemented for the macOS kernel and discuss the limitations that come with it; in the second post, we will present our solution for a better macOS debugging experience.

This blog post is about examining an Android security patch and understanding how it mitigates the vulnerability.