About

I’m interested in cybersecurity, cryptography, law, privacy, (secure) software development and a lot of other things. I like to create new things that are useful for other people, especially regarding cybersecurity. Since passwords are often the weakest link in cybersecurity, the effect of improving is relatively big. For this reason, I started Chiff, an app that works as a password manager, but without the usability and security disadvantages of a master password. I strongly believe usability is an important (and often overlooked) aspect in security products. If a very secure product is not usable it won’t be used and if it won’t be used, it won’t deliver any security advantages. With Chiff, we aim to make it as effortless as possible for people to be secure.

Work

From 2013 until 2018, I’ve worked at the Dutch national prosecutor’s office, where I was developing strategies for investigating cyber(-enabled) crime, in particular darknet markets. In 2016, I started the investigation that eventually resulted in the takeover of Hansa market in 2017. More information about this operation can be found on different media:

In 2018, I started working on Chiff (formerly known as Keyn), which is currently my main focus. For Chiff, I do most of the architecture design, security and development (iOS app, Android app, browser extension, backend). Technologies I like to work with:

  • Programming languages: Swift, Kotlin, Typescript, Python
  • Frameworks: React, Middleman, Jekyll
  • Tools: Webpack, Git, Sketch, Prettier, SwiftLint, ESLint
  • Infrastructure: Ansible, AWS Lambda, DynamoDB, SNS, SQS and Cloudformation

Furthermore I regularly perform as a public speaker on different subjects, mainly cybersecurity and the takeover of Hansa Market. I occasionally give trainings and do consultancy work for Interpol and other organisations.

Education

  • I’ve studied criminology (BSc) and criminal justice (MSc) from 2008 to 2013 at Leiden University. For my master thesis, I completed a quantitative analysis of the effectivity of prosecuting cocaine-related cases at the national prosecutor’s office.
  • After graduating in criminology, I decided to study computer science (BSc) as well at Open University, which I finished in 2016. I wrote my thesis about an anoymization model for Twitter, which I formally verified with the applied pi calculus.
  • From 2016 I studied information security (MSc) at Royal Holloway, University of London. In 2019, I graduated with distinction on the cryptographical protocols that form the core of Chiff.