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OT (software) engineer by day, asleep at night (with a bit of luck), nerd all the time.
Started as PLC/SCADA programmer, but just like hobbies, this wasn't enough so at some point that turned into adding MES, bit of networking, virtualisation, etc.
Hobbies include yapping into a microphone about privacy, security, nerdy and WHY-related stuff.

  • OT Cyberchallenges 2
Anne Jan Brouwer

Hacker, developer, head of engineering.

Started playing with computers age 6, never stopped.

  • Prepping for camp or crisis
Anne Ogborn
  • Hacking the international travel system
Anykey

Amateur maker, hacker and coder. Fan of OpenSCAD, python, AI / LLMs, Cloud, 3D Printing, CNC and making things old-school by hand.

  • How do models like ChatGPT (LLM) work, can you hack them and run them offline?
Boekenwuurm

Fan van Paars

  • Van de GHP tot why2025: De geschiedenis en toekomst van de nederlandse hackercamps
  • The pubquiz!
Brenno de Winter

Brenno de Winter is hacker, gerenommeerd informatiebeveiligingsexpert, auteur en veelgevraagd spreker met meer dan 30 jaar ervaring op het snijvlak van technologie, veiligheid en menselijk gedrag. Geboren in 1971, ontwikkelde hij zich tot een pionier in de wereld van digitale beveiliging en privacy. Brenno staat bekend om zijn scherpe analyses, praktische benadering en vermogen om complexe vraagstukken toegankelijk te maken voor een breed publiek.

In 2011 werd hij uitgeroepen tot Journalist van het Jaar, mede dankzij zijn onderzoeksjournalistiek rond beveiligingsincidenten. Deze ervaring vormde de basis voor zijn werk aan de MIAUW-methodiek (Methodiek voor Informatiebeveiligingsonderzoek met Auditwaarde), een gestructureerd framework voor penetratietesten dat reproduceerbaarheid, auditwaarde en transparantie centraal stelt.

Brenno is de auteur van De Validatiecrisis, waarin hij laat zien hoe een gebrek aan kritisch denken en validatie grote risico’s vormt voor technologie en maatschappij. Zijn werk benadrukt de noodzaak van grondige controle, ethische reflectie en heldere communicatie in een wereld die steeds meer afhankelijk wordt van technologie.

Naast zijn werk als schrijver en onderzoeker geeft Brenno regelmatig trainingen aan CISO's, beleidsmakers en technologische leiders. Hij is gespecialiseerd in NIS2-compliance, risicomanagement en de juridische aspecten van digitale veiligheid. Met zijn unieke combinatie van expertise, humor en storytelling inspireert hij zijn publiek om technologie kritisch en verantwoord te benaderen.

Brenno de Winter blijft een voorvechter van transparantie en validatie in technologie, met een missie om de digitale wereld veiliger en eerlijker te maken. Zijn werk heeft een blijvende impact op zowel professionals als organisaties die streven naar duurzame en betrouwbare oplossingen in een steeds complexere digitale samenleving.

  • De validatiecrisis
  • Operation Check Mate: De Rechtszaak
Chris van 't Hof

Chris is one of the co-founder of DIVD and Managing Director since 1 January 2022. He entered cyber security through his experience as researcher and wrote two books on Coordinated Vulnerability Disclosure: “Helpful Hackers” (2016) and “Cyberellende was nog nooit zo leuk” (2021). With his unusual background in electrical engineering and sociology, he analyzes how human and electronic networks interact. As presenter he took the stage over 700 times and organized and hosted many talk shows, such as Hack Talk (2017-2022). Combining these experiences and skills he also provides cyber crisis management training to a broad range of organizations. You may say this is not a typical background for a Managing Director, but it works for DIVD. Chris perceives himself not as the boss, but rather a translator who explains to the outside world how hackers can help and aims to provide nerds a safe space to do their thing.

  • Workshop fire breathing
  • How to do vulnerability disclosure in Japan
  • Helpful hackers preventing evil hackers from crashing the grid
Dennis van Zuijlekom
  • Portrait Photography Studio: "Shoot ALL the Hackers!"
  • Portrait Photography Studio: "Shoot ALL the Hackers!"
  • Portrait Photography Studio: "Shoot ALL the Hackers!"
Dimitri
  • Openingstalk Hackerhotel 2025
Dimitri
  • Closing Hackerhotel 2025
Dina Tuinhof
  • Dutch Fun! (damentals)
Dirk Maij

Dirk is working with computers since the moment they became commercially available. He has more than 20 years of professional experience in developing software and is over 20 years active in cyberscurity, where he started out as a cryptographer. He is one of the founders of Onyx Cybersecurity and is active in multiple organisations focusing on cybersecurity and making the world a safer place.

  • Crypto 101
Elborro

Passionate OT/ICS cybersecurity veteran with a love for hacking, 3D printing, electronics, and sharing tech skills with the next generation. Dedicated to privacy advocacy, open-source tools, and promoting hacking as a creative force for good. A proud member of Hackerhotel orga, volunteering across WHY2025 teams info, promo, and finance, and championing inclusivity and kindness. Big fan of science fiction, space exploration, and people who embrace individuality and pay it forward. Advocate for a future where technology empowers democracy and human rights. 🚀💡

  • OT Cyberchallenges 2
  • Meshtastic Fantastic
  • Get started with Meshtastic
Elger "Stitch" Jonker

Basisbeveiliging, MCH2022, SHA2017, Awesome Space, Hack42 etc etc etc CYBER

  • Basisbeveiliging / Internet Cleanup Foundation - State of the map 2024
  • Evolution and history of 33.333 years of Hardcore Music
Fleur van Leusden

Fleur is the CISO for the Dutch Electoral Council. As such, she is the organisations trusted advisor around information security of the election process as well as internal processes.

  • Don't Trust Us
Frank Breedijk

Balloon folding clown, fire breathing amateure, CISO at Schuberg Philis, Ciris manager at DIVD, author of Seccubus, starting bee keeper.

  • Nerding out over silly machines
  • Workshop fire breathing
  • Balloon folding (for kids and adults)
  • Frank talks AI, keynote style
FrankkieNL

FrankkieNL is an Android App developer, who loves 3D printing.

  • Android Auto (Flitsmeister)
Jean-Paul Sablerolle

https://www.linkedin.com/in/jpsablerolle/

  • The "O" in OT
Jeroen Baten

Jeroen Baten is al ruim 30 jaar bedrijfsconsultant en specialiseert zich binnen
de informatietechniek in Linux en open source software. Daarnaast was hij 10
jaar brandweerman waar hij de nodige dingen meemaakte.

Hij deelt graag de door hem geleerde levenslessen om anderen te helpen en te informeren. Jeroen is soms actief als JeroenBaten op Mastodon, maar
eigenlijk probeert hij social media zoveel mogelijk te vermijden. Zijn
professionele carrière is te vinden op LinkedIn, waar hij soms ook berichten
plaatst over relevante onderwerpen uit zijn vakgebied. Zijn persoonlijke blog
is te vinden op https://www.jeroenbaten.nl. Als hobby leest hij graag,
verzamelt hij AS/400 systemen en speelt hij graag met synthesizers en
computers.

  • Workshop loosing weight
  • I love historical computing. to the moon and back
jos

Author, Nerd, Speaker, somethingsomething locks. Not necessarily in that order.

  • Getting a feel for lockpicking (opening up the world of locksport for the visual impaired)
Karl Lovink

Karl Lovink is the Technical Lead of the Dutch Tax and Customs Administration's security operations center (SOC). He must ensure that the SOC's security analysts can do their jobs well in the technical field. In addition, he is responsible, among other things, for strengthening the network of governments and companies so that the right. He loves technology and has 10 RFID / NFC chips implanted in his body, including a credit card.

  • A criminal, and victim view of phishing and phishing panels, live of stage.
Lord BugBlue

Ooit geboren

Kon al typen voordat ik kon schrijven.

Snapt computers en data, maar dan echt.

Expert in cryptografie en dingen met computers die andere mensen niet doen.

Werk voor en tegen de overheid, overdag betaalt de overheid me soms ook voor dat werk.

Foto origineel: https://flic.kr/p/Am8qQE

  • Wat is data
Maja

Maja, iets met wiskunde.

  • Abacus workshop
  • Abacus workshop
  • Abacus workshop
Marieke

Also known as: piiindakaas (she/her).
Her mission? Helping nerds and hackers (homo cyberneticus) communicate clearly and effectively with non-hacking people (homo ordinarius). She also believes it's long overdue to reshape the stigma surrounding hackers.

She joined DIVD in 2021 as a communication specialist, and in 2024, she became the new Head of Communications, leading the effort to build the communication team.

Beyond DIVD, she's also part of the Project Lead team for WHY2025, the Dutch hacker camp.
By day, she works as a communication specialist at a cybersecurity company.

  • A Communication’s Guide To The Hackerscene
Mattijs

Mattijs is a problem solver. He has been working in the Cyber Security industry for almost a decade as an OSINT analyst, forensic analyst and incident handler. He uses his experience to keep on innovating and improving the way incident response is executed.

  • Automating incident response: scalable & fast, within minutes
Mischa Rick van Geelen

Hi! I’m Mischa Rick van Geelen, founder of Anovum B.V., a leading cybersecurity company. I have investigated and resolved large-scale cyber incidents, including the attacks on Hof van Twente and ROC Mondriaan (publicly documented), and have been involved in numerous anonymous incidents. Additionally, I conducted the penetration test on the CoronaMelder app, with the results submitted to the Dutch Parliament, and I actively contribute to the development of the MIAUW methodology.

As a security consultant, incident responder, and digital forensic investigator, I help organizations strengthen their IT security, investigate incidents, and resolve issues. My expertise includes secure software development, network security, and the implementation of EDR/XDR solutions. I also provide workshops and lectures to enhance cybersecurity awareness.

  • A (small) history-lesson on ransomware, modern-day tactics and suprising data-recovery options
Moem

I was born at a very young age. I'm a tinkerer and a maker, who loves making stuff into other stuff. I'm also a founder of hackerspace Hack42 in Arnhem. And you can always feel free to ask me about Ubuntu Touch or my cats!

  • Fun with Bleach
  • Magic Gemstone Jewellery
Nancy Beers
  • Make WHY2025 awesome! - Workshops/sweatshops/Tiny Tasks.
  • Make WHY2025 awesome! - Workshops/sweatshops/Tiny Tasks.
  • Make WHY2025 awesome! - Workshops/sweatshops/Tiny Tasks.
  • Make WHY2025 awesome! - Workshops/sweatshops/Tiny Tasks.
Nick Bouwhuis

Hi! My name is Nick and I’m a Network Engineer at Speakup a leading communications provider located in Enschede. I’m passionate about technology and all things IT. I also run a small business on the side that helps small businesses in the area with IT-related tasks like management, security, networking and more.

Networking and connecting certainly is something that really piques my interest. And I hope to transfer some of my enthusiasm in this field to you.

  • How to become your own ISP
Niels Hatzmann

Niels is a freelancer by day, idealist by night. Currently, he works for the Dutch Electoral Council as teamlead of the Abacus development team. He collects hobbies which require a licence or permit and loves to build and tinker with actual things. Ask him anything about desert racing, for instance.

On saturday morning he hosts a workshop on Abacus, the new software for the Dutch Elections. Come and check out this nice open source project! In the afternoon, together with Roman Kniaziev from Kharkiv, he will speak about their project to support Ukraine, which needs all the help it can get.

  • Abacus - about the new software for the Dutch Elections
  • Aid to Ukraine - what can we do to help?
Orange_Murker
  • Build your own parametric speaker
Paul Honig
  • Tanmatsu/WHY2025 badge PCB design
Peter op 't Hof

Peter op ‘t Hof werkt sinds 2008 bij de politie en is kaderlid van de ACP. Peter werkt als clusterarchitect, hij ontwerpt oplossingen die te maken hebben met waarnemingen. Je moet dan denken aan waarnemingssystemen, zoals camera’s, bewegingssensoren enz. Wij zorgen er met onze systemen voor dat de operationele diensten en meldkamers door kunnen draaien.

Ik vind het een uitdaging om de balans te vinden tussen informatietechnologie, business-governance en kwaliteit van mensen en groepen, om motivatie, inspiratie en gezondheid op het werk te brengen met bruikbare oplossingen.

  • Hacking with screenreaders as tool or utility
Renze Nicolai
  • Tanmatsu/WHY2025 badge PCB design
Richard Kraaijenhagen

Richard Kraaijenhagen is the Director of C42X Fusion Research, a private fusion research institute devoted to improving fusion plasma control through machine learning techniques.

  • Thermonuclear Fusion: Controlling the Power of the Stars for a Sustainable Future
Rik van Duijn

Rik has over 10 years of experience in offensive security area working as a penetration tester. Next to his work assessing the security of infrastructures, he spends time researching trends within IT security and on developing defensive measures.

  • AiTM: Lessons Learned
Roxane

Unofficial:
Keeping hackers happy @ DIVD and doing cyber stuff @ the Government

Official:
Head of People and Culture @ DIVD and Kwartiermaker Cyber Resilience @ Min Buza

  • A Communication’s Guide To The Hackerscene
SchizoDuckie

The Lamest Hacker You Know.
I find your passwords because you uploaded them.

  • My stairs use 6 IP Addresses and run JavaScript
stefan lambregts
  • Don’t judge a vulnerability by its CVSS score
Wesley Neelen
  • AiTM: Lessons Learned
Wouter

Builds satellites for hobby and a living. network admin & security.

Radio amateur callsign and nickname PA3WEG
Sound engineer, videographer and allround electronics nutter

Does it have wires? I like it!

  • What's that CubeSat Satellite stuff anyhow?
Zawadi Done

Zawadi Done is an Incident Responder at Hunt & Hackett. He has worked in the Cyber Security industry for six years in various roles as cyber security consultant, DevOps engineer and developer.

  • Automating incident response: scalable & fast, within minutes
Ze Foxx
  • DJ Ze Foxx
  • DJ Ze Foxx