The mobile phone has become an important part of people's lives and which apps are used says a lot about a person. Even though data is encrypted, meta-data of network traffic leaks private information about which apps are being used on mobile devices.Apps can be detected in network traffic using the network fingerprint of an app, which shows what a typical connection of the app resembles. In this work, we investigate whether fingerprinting apps is feasible in the real world. We collected automatically generated data from various versions of around 500 apps and real-world data from over 65 unique users. We learn the fingerprints of the apps by training a Random Forest on the collected data. This Random Forest is used to detect app fingerprints in network traffic. We show that it is possible to build a model that can classify a specific subset of apps in network traffic. We also show that it is very hard to build a complete model that can classify all possible apps traffic due to overlapping fingerprints. Updates to apps have a significant effect on the network fingerprint, such that models should be updated every one or two months. We show that by only selecting a subset of apps it is possible to successfully classify network traffic. Various countermeasures against network traffic analysis are investigated. We show that using a VPN is not an effective countermeasure because an effective classifier can be trained on VPN data. We conclude that fingerprinting in the real world is feasible, but only on specific sets of apps.

The Dutch electoral voting system is designed in a way that does not fit in the current era of the digital transformation. Almost every procedure during the elections is done manually and change in policy is very difficult as it requires a change in legislation.
This thesis explores a more trustworthy, transparent and less expensive way of verifying the suffrage of a citizen. In order to accomplish this, a literature review is presented about the election process in other countries and new possibilities with state of the art technology are reviewed. Based on these investigations, a solution that would make the current voting pass superfluous is presented. The presented solution in this thesis is built with blockchain and machine readable travel documents. Considering blockchain, this technology is a decentralized ledger of transactions, where every transaction is
immutable and built following predefined rules. These transactions are visible and verifiable for anyone connected to the decentralized network. Due to this decentralized design, the network is resilient against DDoS attacks and has no single point of failure. Machine readable travel documents are used for the authentication. Dutch travel documents (passports, identity cards and driver’s licences) are designed according to the ICAO machine readable travel document standard, which also requires the presence of a biometric chip. This means that every citizen already has access to a PKI (public key infrastructure) key pair, which can be used to sign data. The presented solution combines these technologies and is first of its kind to link a machine readable travel document to a blockchain. These new possibilities can help solving the identity problem for all kinds of
organizations