CryptoDB
Zhelei Zhou
Publications
Year
Venue
Title
2022
ASIACRYPT
GUC-Secure Commitments via Random Oracles: New Impossibility and Feasibility
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Abstract
In the UC framework, protocols must be subroutine respecting; therefore, shared trusted setup might cause security issues. To address this drawback, Generalized UC (GUC) framework is introduced by Canetti {\em et al.} (TCC 2007).
In this work, we investigate the impossibility and feasibility of GUC-secure commitments using global random oracles (GRO) as the trusted setup. In particular, we show that it is impossible to have a 2-round (1-round committing and 1-round opening) GUC-secure commitment in the global observable RO model by Canetti {\em et al.} (CCS 2014). We then give a new round-optimal GUC-secure commitment that uses only Minicrypt assumptions (i.e. the existence of one-way functions) in the global observable RO model. Furthermore, we also examine the complete picture on round complexity of the GUC-secure commitments in various global RO models.
Coauthors
- Kui Ren (1)
- Bingsheng Zhang (1)
- Hong-Sheng Zhou (1)