CryptoDB
Xingjian Li
Publications
Year
Venue
Title
2022
CRYPTO
On the Feasibility of Unclonable Encryption and, More
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Abstract
Unclonable encryption, first introduced by Broadbent and Lord (TQC'20), is a one-time encryption scheme with the following security guarantee: any non-local adversary (A, B, C) cannot simultaneously distinguish encryptions of two equal length messages. This notion is termed as unclonable indistinguishability. Prior works focused on achieving a weaker notion of unclonable encryption, where we required that any non-local adversary (A, B, C) cannot simultaneously recover the entire message m. Seemingly innocuous, understanding the feasibility of encryption schemes satisfying unclonable indistinguishability (even for 1-bit messages) has remained elusive.
We make progress towards establishing the feasibility of unclonable encryption.
(*) We show that encryption schemes satisfying unclonable indistinguishability exist unconditionally in the quantum random oracle model.
(*) Towards understanding the necessity of oracles, we present a negative result stipulating that a large class of encryption schemes cannot satisfy unclonable indistinguishability.
(*) Finally, we also establish the feasibility of another closely related primitive: copy-protection for single-bit output point functions. Prior works only established the feasibility of copy-protection for multi-bit output point functions or they achieved constant security error for single-bit output point functions.
Coauthors
- Prabhanjan Ananth (1)
- Fatih Kaleoglu (1)
- Qipeng Liu (1)
- Mark Zhandry (1)