Bryan Ford gave this talk as part of the ViSP Distinguished Lecture Series (https://visp.wien/lecture-series).


Abstract: Internet technologies have often been called “democratizing” by virtue of giving anyone a voice in countless online forums. Technology cannot actually be “democratizing” by democratic principles, however, unless it serves everyone, offers everyone not just a voice but an equal voice, and is accountable to and ultimately governed by the people it serves. Today's technology offers not democracy but guardianship, subjecting our online lives to the arbitrary oversight of unelected employees, committees, platforms, and algorithms, which serve profit motives or special interests over our broader interests. Can we build genuinely democratizing technology that serves its users inclusively, equally, and securely?
A necessary first step is digital personhood: enabling technology to distinguish between real people and fake accounts such as sock puppets, bots, or deep fakes. Digital identity approaches undermine privacy and threaten our effective voice and freedoms, however, both in existing real-world democracies and in online forums that we might wish to embody democratic ideals. An emerging ecosystem of “proof of personhood” schemes attempts to give willing participants exactly one credential each while avoiding the privacy risks of digital identity. Proof of personhood schemes may operate in the physical world or online, building on security foundations such as in-peron events, biometrics, social trust networks, and Turing tests. We will explore the promise and challenges of secure digital personhood, and the tradeoffs of different approaches along the key metrics of security, privacy, inclusion, and equality. We will cover further security challenges such as resisting collusion, coercion, or vote-buying. Finally, we will outline a few applications of secure digital personhood, both already prototyped and envisioned.