The homepage of Jan Hrach

I work as Linux administrator, I create embedded designs and I write software (preferably lowlevel, parallel, respecting the UNIX philosophy, from the field of signal processing, networks or cryptography). I can quickly introduce myself into almost any programming language or technology and produce drafts of seemingly impossible things. You can find some of my projects below.

I have finished bachelor program General Computer Science (thesis) and master program Software and data engineering (thesis) on Charles University. I was an active member of brmlab, the Prague hackerspace. Though I'm a "computers guy" by profession, my interests are much broader, including everything from biology over physics to engineering.

I ride bike as the only mean of commuting everyday. Once a while I go to a longer biketrip too. You can join me if you wish :)


A5/1 cracker accelerated with OpenCL


network-transparent SDR software


a live video streamer


GSM sniffing and decoding toolkit


The fastest channelizer in Litoměřice!


realtime the entire Tetra network!

My articles

AbcLinuxu (Czech) - Linux, OpenSource, security (Czech) - Bitcoin, computer security

KP (Czech) - civil rights advocacy

My talks (in Czech)

Misc. user page - lots of useful tips and code snippets

Videoserver - recordings of various lectures

More code!






I contribute to:


decode metadata and maybe more




You can talk to me in Czech, Slovak or English.

OpenPGP key, fingerprint 83D1 4B71 ECBA 248D DA10 2075 0A2B 8047 0F08 9D1E.

  • E-mail: jenda .a. hrach ... eu.
  • Jabber: hrachj .a. abclinuxu ... cz, hrachj .a. jabber ... cz, OTR FP
  • IRC: Jenda` on #brmlab on freenode
  • HAM: OK1DNA in JO70FB
  • IČ (czech tax identification number): 887 88 954
  • Phone: 4.2073766063E+11