Abstract 3

Acknowledgements 4

Executive summary 5

1. Introduction 11

 1.1. Background of the study 11

 1.2. Focus and objectives of the report 12

 1.3. Main collaborators 13

 1.4. Overview of the content of the report 13

 1.5. Methodology 14

2. What are privacy enhancing technologies and why are they relevant for law enforcement? 17

 2.1. Privacy enhancing technologies: definition and purpose 17

 2.2. Data privacy explained 18

 2.3. Classification of privacy enhancing technologies 20

 2.4. Main problems that privacy enhancing technologies address 21

 2.5. Proliferation of privacy enhancing technologies: trends 23

 2.6. Relevance of privacy enhancing technologies in law enforcement 24

3. Key privacy enhancing technologies for law enforcement - results of the workshop 26

 3.1. Deepfake detection 27

 3.2. Interception-resistant communication 28

 3.3. Internet of behaviour 29

 3.4. Multiple layers of biometric security 29

 3.5. Privacy-preserving machine learning 30

 3.6. Tiny solar-powered drones 31

 3.7. Foundations of AI 32

 3.8. Adversarial signal injection 34

 3.9. Trusted execution environments 35

 3.10. Humanoid robots 36

4. Glancing at the long-term horizon 38

 4.1. New developments in cryptography 38

 4.2. AI: new developments related with privacy 42

 4.3. Quantum communications: safer than ever 47

 4.4. 6G: the next generation of wireless communication technologies 49

 4.5. Blockchain: look for new use cases 52

 4.6. Section endnote 55

5. Contextual factors for the development and uptake of privacy enhancing technologies (PETs) 56

 5.1. Contextual factors according to the PESTEL methodology 59

6. Conclusions 65

 6.1. Most promising privacy enhancing technologies 65

 6.2. The key contextual factors 66

 6.3. Criminal threats and hindering law enforcement 67

 6.4. Priorities for EU funding 68

References 70