15 papers
Failing gracefully: Decryption failures and the Fujisaki-Okamoto transform
Kathrin Hövelmanns, Andreas Hülsing, Christian Majenz
In known security reductions for the Fujisaki-Okamoto transformation, decryption failures are handled via a reduction solving the rather unnatural task of finding failing plaintext…
Efficient NIZKs and Signatures from Commit-and-Open Protocols in the QROM
Jelle Don, Serge Fehr, Christian Majenz +1
Commit-and-open Sigma-protocols are a popular class of protocols for constructing non-interactive zero-knowledge arguments and digital-signature schemes via the Fiat-Shamir transfo…
A Guide for New Program Committee Members at Theoretical Computer Science Conferences
Yfke Dulek, Stacey Jeffery, Christian Majenz +3
In theoretical computer science, conferences play an important role in the scientific process. The decisions whether to accept or reject articles is taken by the program committee…
Limitations on Uncloneable Encryption and Simultaneous One-Way-to-Hiding
Christian Majenz, Christian Schaffner, Mehrdad Tahmasbi
We study uncloneable quantum encryption schemes for classical messages as recently proposed by Broadbent and Lord. We focus on the information-theoretic setting and give several li…
Quantum-access security of the Winternitz one-time signature scheme
Christian Majenz, Chanelle Matadah Manfouo, Maris Ozols
Quantum-access security, where an attacker is granted superposition access to secret-keyed functionalities, is a fundamental security model and its study has inspired results in po…
Online-Extractability in the Quantum Random-Oracle Model
Jelle Don, Serge Fehr, Christian Majenz +1
We show the following generic result. Whenever a quantum query algorithm in the quantum random-oracle model outputs a classical value that is promised to be in some tight relat…