|COOKIES: By using this website you agree that we can place Google Analytics Cookies on your device for performance monitoring.|
Malleability in Modern Cryptography
If you have a question about this talk, please contact Microsoft Research Cambridge Talks Admins.
This event may be recorded and made available internally or externally via http://research.microsoft.com. Microsoft will own the copyright of any recordings made. If you do not wish to have your image/voice recorded please consider this before attending
In recent years, malleable cryptographic primitives have advanced from being seen as a weakness allowing for attacks, to being considered a potentially useful feature. Malleable primitives are cryptographic objects that allow for meaningful computations, as most notably in the example of fully homomorphic encryption. Malleability is, however, a notion that is difficult to capture both in the hand-written and the formal security analysis of protocols.
In my work, I look at malleability from both angles. On one hand, it is a source of worrying attacks that have, e.g., to be mitigated in a verified implementation of the transport layer security (TLS) standard used for securing the Internet. On the other hand, malleability is a feature that helps to build efficient protocols, such as delegatable anonymous credentials and fast and resource friendly proofs of computations for smart metering. We are building a zero-knowledge compiler for a high-level relational language (ZQL), that systematically optimizes and verifies the use of such cryptographic evidence.
We recently discovered that malleability is also applicable to verifiable shuffles, an important building block for universally verifiable, multi-authority election schemes. We construct a publicly verifiable shuffle that for the first time uses one compact proof to prove the correctness of an entire multi-step shuffle. In our work, we examine notions of malleability for non-interactive zero-knowledge (NIZK) proofs. We start by defining a malleable proof system, and then consider ways to meaningfully ‘control’ the malleability of the proof system. In our shuffle application controlled-malleable proofs allow each mixing authority to take as input a set of encrypted votes and a controlled-malleable NIZK proof that these are a shuffle of the original encrypted votes submitted by the voters; it then permutes and re-randomizes these votes and updates the proof by exploiting its controlled malleability.
This talk is part of the Microsoft Research Cambridge, public talks series.
This talk is included in these lists:
Note that ex-directory lists are not shown.
Other listsCentre for Global Equality Annual Disability Lecture Lennard-Jones Centre
Other talksArt speak A V HILL LECTURE - Title to be confirmed Molecular and cellular studies of membrane perforation in the arms race between host and pathogen The economics of the ‘Second Slavery’ in the Jihad states of West Africa *Please note that this talk has been cancelled* Investigating Cultures of Community Energy