Hierarchies in Unclonable Cryptography
- LecturerMr. Omri Shmueli (Tel Aviv University)
Host: Chung, Kai-Min - Time2022-09-08 (Thu.) 14:00 ~ 16:00
- LocationAuditorium 106 at IIS new Building
Abstract
Unclonable Cryptography studies cryptographic schemes that are based on quantum token schemes - a scheme where a sender can generate and distribute quantum unclonable states in a system of receivers. These schemes are the basis for many of the high-end primitives in quantum cryptography, like public-key quantum money.
Quantum tokens can be extended to have additional properties well beyond the standard definition that only demands the token to be unclonable. Elegantly, these extensions in fact create a well-structured hierarchy of quantum primitives, starting from standard quantum tokens which are known to exist unconditionally, through public-key quantum tokens that are known to exist based on Indistinguishability Obfuscation, to Quantum Lightning and One-Shot Signatures, which we do not know how to construct from any computational assumption.
In this talk we will have two parts:
1. A tender introduction to the hierarchy of unclonable cryptography and what's known.
2. A technical part, where we show how to construct one of the primitives in this hierarchy, called Semi-Quantum Tokenized Signatures (a paper from this CRYPTO 2022).
Quantum tokens can be extended to have additional properties well beyond the standard definition that only demands the token to be unclonable. Elegantly, these extensions in fact create a well-structured hierarchy of quantum primitives, starting from standard quantum tokens which are known to exist unconditionally, through public-key quantum tokens that are known to exist based on Indistinguishability Obfuscation, to Quantum Lightning and One-Shot Signatures, which we do not know how to construct from any computational assumption.
In this talk we will have two parts:
1. A tender introduction to the hierarchy of unclonable cryptography and what's known.
2. A technical part, where we show how to construct one of the primitives in this hierarchy, called Semi-Quantum Tokenized Signatures (a paper from this CRYPTO 2022).