Paper 2021/412

Uncloneable Encryption, Revisited

Prabhanjan Ananth and Fatih Kaleoglu

Abstract

Uncloneable encryption, introduced by Broadbent and Lord (TQC'20), is an encryption scheme with the following attractive feature: an adversary cannot create multiple ciphertexts which encrypt to the same message as the original ciphertext. The constructions proposed by Broadbent and Lord have the disadvantage that they only guarantee one-time security; that is, the encryption key can only be used once to encrypt the message. In this work, we study uncloneable encryption schemes, where the encryption key can be re-used to encrypt multiple messages. We present two constructions from minimal cryptographic assumptions: (i) a private-key uncloneable encryption scheme assuming post-quantum one-way functions and, (ii) a public-key uncloneable encryption scheme assuming a post-quantum public-key encryption scheme.

Note: Submitted to TQC'21