I build web applications and I'm into web application security. I like to speak about secure development. My mission is to teach web developers how to build secure and fast web applications and why. (more about me, contact)

My trainings

And this is what they say about them: Originally, I've arranged Michal's training primarily for my colleagues because "of course I already know these things"... Michal has changed my mind in the first hour of the first day and continued to do so for the whole two days. Thanks to this training I finally understood some of the attack/defense concepts in full depth, and especially in the right context. — Jan Pospíšil, Senior PHP developer, Czech Radio

Public trainings

Come to my public trainings, everybody's welcome:

Trainings in Prague are held regularly in the middle of March, June, September, and December, in other cities irregularly.

In-house trainings

Any public training can also be turned into an in-house training. As an extra, I offer these in-house-only courses:

Looking for Introduction to PHP, Classes and objects in PHP? I've handed them over to Martin Hujer. I've discontinued Web application performance, Martin Michálek runs a similar training.

My articles

Slovak websites in the “Collection #1” password database and friends
January 23, 2019

Yesterday I checked Czech websites in “Collection #1” and others (like “Collection #2” to “Collection #5”, “BigDB”), today I've checked Slovak sites. We're neighboring countries and historically have a lot in common, many Czech users have accounts on Slovak sites as well, so it seemed like a good idea.

(read more…)

Czech websites in the “Collection #1” password database and friends
January 22, 2019

Last week was all about the 773 million records data breach, nicknamed “Collection #1”. It's a few years old compilation of previous data leaks but it's still interesting to check which Czech websites (and Slovak, too) are present in this and other databases (like “Collection #2” to “Collection #5”, “BigDB”).

(read more…)

Using JavaScript to modify URLs and hide fbclid
November 7, 2018

Roughly two weeks ago, Facebook started adding a tracking parameter, fbclid (Facebook click id?), to all external links users share. And I didn't like it so I'm hiding it.

(read more…)

All articles

My talks


Upcoming talks

…at your event or conference, let me know!


If MacGyver was a search engine
March 19, 2019, Pipedrive Talks: Security by design (50 minutes)

Zámečky nikoho nezajímají
February 19, 2019, Cyber Security 2019 (40 minutes)

January 14, 2019, PHP UserGroup Dresden Meetup I/2019 – CTF & Security (45 minutes)

Posilujeme defenzivu s Michalem Špačkem aneb Branky, body, bezpečnost
November 29, 2018, Livesport Talk VII (30 minutes)

Úniky dat, co to vůbec je a jak na ně reagovat
November 15, 2018, WebTop100 2018 (25 minutes)

All talks

Me answering questions

Michal Špaček z Report URI o smyslu práce, potenciálu i prokrastinaci
January 15, 2019, StartupJobs

Blokování webů a stránek
June 4, 2016, Český rozhlas Online Plus

Na 11. srazu Na volné noze
June 4, 2016, 11. sraz Na volné noze

Webový vývojář musí mít hackerské myšlení
May 30, 2016, Kyberbezpečnost.cz

Hlavní je používat hlavu, ale ne na hesla
May 3, 2016, Host Radiožurnálu

All interviews