The REsearch centre on Privacy, Harm Reduction and Adversarial INfluence online (REPHRAIN) will bring together the UK's substantial academic, industry, policy and third sector capabilities to address the current tensions and imbalances between the substantial benefits to be gained by full participation in the digital economy and the potential for harm through loss of privacy, insecurity, disinformation and a myriad of other online harms. Combining world-leading experts from the Universities of Bristol, Edinburgh, Bath, King's and UCL, the REPHRAIN Centre will use an interdisciplinary approach - alongside principles of responsible innovation and creative engagement - to develop new insights that allow the socio-economic benefits of a digital economy to be maximised whilst minimising the online harms that emerge from this. REPHRAIN's leadership team will drive these insights in technical, social, behavioural, policy and regulatory research on privacy, privacy enhancing technologies and online harms, through an initial scoping phase and 25 inaugural projects. The work of REPHRAIN will be focused around three core missions and four engagement and impact objectives. Mission 1 emphasises the requirement to deliver privacy at scale whilst mitigating its misuse to inflict harms. This will focus on reconciling the tension between data privacy and lawful expectations of transparency by not only drawing heavily on advances in privacy-enhancing technologies (PETs), but also leveraging the full range of socio-technical approaches to rethink how we can best address potential trade-offs. Mission 2 emphasises the need to minimise harms whilst maximising the benefits from a sharing-driven digital economy, redressing citizens' rights in transactions in the data-driven economic model by transforming the narrative from privacy as confidentiality only to also include agency, control, transparency and ethical and social values. Finally, Mission 3 focuses on addressing the balance between individual agency and social good, developing a rigorous understanding of what privacy represents for different sectors and groups in society (including those hard to reach), the different online harms to which they may be exposed, and the cultural and societal nuances impacting effectiveness of harm-reduction approaches in practice. These missions are supported by four engagement and impact objectives that represent core pillars of REPHRAIN's approach: (1) design and engagement; (2) adoption and adoptability; (3) responsible, inclusive and ethical innovation; and (4) policy and regulation. Combined, these objectives will deliver co-production, co-creation and impact at scale across academia, industry, policy and the third sector. These activities will be complemented by a capability fund, which will ensure that REPHRAIN activities remain flexible and responsive to current issues, addressing emerging capability gaps, maximising impact and cultivating a public space for collaboration. REPHRAIN will be managed by a Strategic Board and supported by an External Advisory Group, the REPHRAIN Ethics Board, and will work with multiple external stakeholders across industry, public, and the third sector. Outcomes from the centre will be synthesised into the REPHRAIN Toolbox - a one-stop resource for researchers, practitioners, policy-makers, regulators and citizens - which will contribute to developing a culture of continuous learning, collaboration and open engagement and reflection within the area of online harm reduction. Overall, REPHRAIN focuses on interdisciplinary leadership provided by a highly experienced team and supported by state-of-the-art facilities, to develop and apply scientific expertise to ensure that the benefits of a digital society can be enjoyed safely and securely by all.

Anonymous communication networks (ACNs), like Tor and mix networks, protect our sensitive communication meta-data, such as whom we talk with, how often we chat and for how long. This meta-data is privacy sensitive since it can be used to reveal secrets that might otherwise be hidden, even when end-to-end encryption is used. This project is timely since mainstream interest in communication privacy on the Internet has grown since the Snowden-revelations about state-level mass surveillance. However, it is a challenge for ACNs to be deployed since it is hard to tune system parameters that matches the actual realised level of privacy. This is due to the fact that the privacy, security, and performance of ACNs is critically impacted by environmental conditions and user behaviour. For example, it is often assumed that messages are not fragmented---broken up into smaller pieces---as they flow over the network. However, the reality is that messages are routinely broken up for performance reasons. Similarly, it is assumed that there is a constant level of user activity, however, users tend to have diurnal activity cycles with bursts and lulls throughout the day. To remedy this current situation, this project aims to bridge the fundamental gaps and provides a framework and a set of methodologies to measure, analyse, and tune ACNs in realistic settings. It does this by pursuing three objectives: 1. Mapping & Tuning: New analysis to uncover and formalise relationships between abstract security parameters and real-world network measurements with the view to optimally tune the ACN. 2. Feedback: Investigate novel ACN designs with feedback loops that provide the ability to automatically tune security parameters at run time. 3. Use-case validation: Evaluate in targeted use-cases of email, web-browsing, and IoT data collection systems to validate the automated tuning methodology. A common occurrence motivates the need for this project. Let us consider an email provider desiring to provide user anonymity as a market differentiator. Referring to the state-of-the-art in the email-securing mix networks literature it is difficult for the non-expert to reason how to correctly parametrise the mix network for the email provider's particular user base. Mapping & Tuning are the missing ingredients holding back deployment. Given a tuned ACN at start-up time, Feedback can be employed to automatically set and adjust the security parameters necessary for the email anonymity service at run time. The provider nor its system administrator needs to become expert in ACN design nor the abstract privacy metrics necessary for manual tuning. This project will leverage recent advancements in the design of mix networks and privacy-preserving network data collection as the basis of our building blocks from which we can extend and enhance. The lasting positive impact of the resultant trustworthy intelligent and adaptive ACNs will be increased adoption and therefore robust privacy for the UK and global public. The technology, data-sets, and tooling developed will open-sourced and will be a boost to the UK privacy technologies marketplace.