BlackAlps19 Blockchain vulnerabilities and exploitation in practice workshop

Posted on Thu 07 November 2019 in dev • Tagged with talks, blackalps, blockchain, ethereum, fumblechain

I gave a 3-hour workshop about blockchain vulnerabilities and exploitation in practice at BlackAlps19 in Yverdon, Switzerland today.

Here are the slides: blackalps19-blockchain-workshop.pdf

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DEF CON 26 talk

Posted on Wed 29 August 2018 in dev • Tagged with talks, defcon, cryptography, big data

If you were in Las Vegas for DEF CON 26 this year you may have seen a talk I gave with my colleague Yolan Romailler about collecting public keys and breaking them.

The video will be uploaded to Youtube eventually and I will update this post with its link. For …

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Posted on Fri 30 June 2017 in dev • Tagged with linux, wireguard, vpn, security

I co-wrote a blog post on WireGuard with adr13n earlier this month.

Read it on

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Playing 10bit HEVC videos on Linux with NVIDIA and mpv

Posted on Fri 26 May 2017 in dev • Tagged with linux, hevc, video

For this to work you will need an NVIDIA GPU.

Get the mpv-build scripts, tune the mpv and ffmpeg options and build:


mkdir -p ~/git
cd ~/git
git clone
cd mpv-build

# write mpv_options file
cat << EOF > mpv_options

# write ffmpeg_options file …

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Setting up gpg-agent

Posted on Sun 30 April 2017 in dev • Tagged with linux, gpg

On Arch gpg-agent comes with the gnupg package so no other package is needed if gpg is already installed.

I use gpg-agent for temporarily caching the PIN for my Yubikey so that I don't have to type it everytime as well as for ssh-agent emulation.


Add the following lines …

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Systemd tips and tricks

Posted on Sun 19 February 2017 in dev • Tagged with linux, systemd

Systemd is great. Here are a few things you can do with it.

Editing unit files

I usually can't remember where unit files are located but that's not an issue. Systemd will let you edit them just by knowing the unit name.

$ export SYSTEMD_EDITOR=vim
$ sudo -E systemctl edit --full …

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Bash Magic

Posted on Fri 02 December 2016 in dev • Tagged with linux, bash

Over the years I have learned many tips and tricks when working with Bash. Some are well known while others are not. Here are a few tricks that I find the most useful.

Searching history

So you know you just typed that command but cannot remember what it was. Fine …

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Spark Summit Europe 2016

Posted on Tue 01 November 2016 in dev • Tagged with conference, spark, big data

I attended Spark Summit Europe 2016 in Brussels this year in October, a conference where Apache Spark enthusiasts meet up. I've been using Spark for nearly a year now on multiple projects and was delighted to see so many Spark users at Square Brussels.

Spark Summit Europe 2016 photo  

There were three trainings to choose …

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