# 2017

## Return of the arsouyes

Thibaut HENIN & Corinne HENIN

After a few years of absence, the arsouyes are back (again). Always the same, but better (obviously).

## Caesar cipher

Thibaut HENIN

The Caesar cipher is a classic in the field of cryptography. Pretty easy to use but also to crack, it have been reviewed so many times.

## RAII Pattern

Thibaut HENIN

To avoid resource management problems (acquisition and release), the RAII pattern is a must known of object-oriented programming. We tell you why.

## PHP Profiler

Thibaut HENIN

When you need to measure the resources taken by some parts of your scripts, rather than taking out the big guns with xDebug, I offer you a handy little class.

## Discrete logarithm

Thibaut HENIN

The discrete logarithm is an algebraic operation whose difficulty is the basis of many modern cryptographic algorithms. This article presents the concepts necessary for its definition as well as its weaknesses in certain specific cases.

## Code Complexity

Thibaut HENIN

It is often needed to estimate the quality of a source code or to point out the risky parts. Whether because your are maintaining it or auditing it, this information allows to direct the work and to accelerate the discovery of bugs or vulnerabilities. Among the usefull metrics, I’ll show you the cyclomatic complexity, the NPath complexity and the cognitive complexity.

## Return of the repository

Thibaut HENIN

Because it's still good to have thematic access, we (finally) took the time to sort the content into categories that may overlap and make it easier for you to find interesting things.

## Échange de clés Diffie-Hellman

Thibaut HENIN

L'échange de clé Diffie Hellman est un des nombreux classiques de la cryptographie moderne. Il permet à la fois d'établir un secret partagé sans nécessiter de canal de communication privé mais est également de fournir une confidentialité persistante entre sessions.

## Diffie-Hellman avec des couleurs

Thibaut HENIN

Pour expliquer le protocole d'échange de clés Diffie-Hellman, beaucoup d'articles et de vidéos utilisent une métaphore avec des couleurs qu'il faut mélanger. Je vous propose ici de pousser cette comparaison jusqu’au bout… que se passerait-il si on l’utilisait vraiment ?

Après avoir expérimenté le PHP, nous revenons aux sources avec une génération statique du site des arsouyes. Pour les curieux, voici comment nous nous y sommes pris.