Welcome to the resource topic for 2020/474
Title:
Tiramisu: Black-Box Simulation Extractable NIZKs in the Updatable CRS Model
Authors: Karim Baghery, Mahdi Sedaghat
Abstract:Zk-SNARKs, as the most efficient NIZK arguments in terms of proof size and verification, are ubiquitously deployed in practice. In applications like Hawk [S&P’16], Gyges [CCS’16], Ouroboros Crypsinous [S&P’19], the underlying zk-SNARK is lifted to achieve Black-Box Simulation Extractability (BB-SE) under a trusted setup phase. To mitigate the trust in such systems, we propose \texttt{Tiramisu}, as a construction to build NIZK arguments that can achieve \textit{updatable BB-SE}, which we define as a new variant of BB-SE. This new variant allows \textit{updating} the public parameters, therefore eliminating the need for a trusted third party, while unavoidably relies on a \textit{non-black-box} extraction algorithm in the setup phase. In the cost of one-time individual CRS update by the parties, this gets around a known impossibility result by Bellare et al. from ASIACRYPT’16, which shows that BB extractability cannot be achieved with subversion ZK (ZK without trusting a third party). \texttt{Tiramisu} uses an efficient public-key encryption with updatable keys which may be of independent interest. We instantiate \texttt{Tiramisu}, implement the overhead, and present efficient BB-SE zk-SNARKs with updatable parameters that can be used in various applications while allowing the end-users to update the parameters and eliminate the needed trust.
ePrint: https://eprint.iacr.org/2020/474
See all topics related to this paper.
Feel free to post resources that are related to this paper below.
Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.
For more information, see the rules for Resource Topics .