Going dark? Analysing the impact of end-to-end encryption on the outcome of Dutch criminal court cases

Former US attorney general William Barr and law enforcement colleagues from other countries have published a statement on end-to-end encryption from which we quote: "while encryption is vital and privacy and cybersecurity must be protected, that should not come at the expense of wholly precluding law enforcement". The main argument put forward by law enforcement is that end-to-end encryption (E2EE) hampers authorities prosecuting criminals who rely on encrypted communication - ranging from drug syndicates to child sexual abuse material (CSAM) platforms. This statement, however, is not supported by empirical evidence, and therefore not suitable as the sole basis of policymaking. That is why, in our work, we analyse public court data from the Netherlands to show to what extent law enforcement agencies and the public prosecution service are impacted by the use of E2EE in bringing cases to court and their outcome. Our results show that Dutch law enforcement appears to be as successful in prosecuting offenders who rely on encrypted communication as those who do not. In contrast to what the US attorney general wants us to believe, at least the prosecution of cases does not seem hampered by E2EE.