Monthly Archives: January 1970


You can contact me by e-mail via sijmen(a), by phone and Signal via +31652627625, or via the contact form below:

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Almost all my professional work is highly confidential and thus I cannot publicize about it. Sometimes I find time in my busy work schedule to write about some of my research which doesn’t fall under a non disclosure agreement: 2017-01-31 Websites Nederlandse politieke … Continue reading

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About me

For over more than 19 years I’m an aficionado for anything related to internet security and developing secure software. I’m specialized in hacking, IT security research and performing advanced penetration testing. My specialty is breaking IT security and then explaining … Continue reading

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In the media

Sometimes the media talks or interviews me about my work, and sometimes I get the opportunity to speak at events: Date Website Subject 2017-02-07 BNR Nieuwsradio An interview about the hack on 2017-02-02 NOS tech podcast A talk about … Continue reading

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My company: Secundity My resume: LinkedIn My short updates: Twitter My presentations: SlideShare

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