Markulf Kohlweiss
I am a professor in the Security and Privacy research group at the University of Edinburgh. I hold a PhD in cryptography from COSIC at the K.U. Leuven and previously was a researcher at Microsoft Research Cambridge in the Programming Principles and Tools group. I worked on the Identity Mixer anonymous credential system at IBM Research Zurich and I am a founding member of the miTLS project, now project Everest, a verified implementation of the TLS standard. For the latter work I am a co-recipient of received the Levchin prize for real-world cryptography.
I am the director of the Edinburgh ZK-Lab.
IOG and University of Edinburgh
Session
In a world where everyone uses anonymous crypto-currencies for all payment needs and anonymous credentials and private smart contracts for all other digital interactions, it is impossible to trace wrongdoers, by design. This makes legitimate controls, such as tracing illicit trade and terror suspects, impossible to carry out. Here, we propose a privacy-preserving blueprint capability that allows an auditor to publish an encoding of the function f(x, - ) for a publicly known function f and a secret input x. For example, x may be a secret watchlist, and f(x, y) may return y if y in x. On input her data y and the auditor's pk_x, a user can compute an escrow Z such that anyone can verify that Z was computed correctly from the user's credential attributes, and moreover, the auditor can recover f(x,y) from Z.