On the Implications from Updatable Encryption to Public-Key Cryptographic Primitives
Yuichi Tanishita, Ryuya Hayashi, Ryu Ishii, Takahiro Matsuda, Kanta Matsuura · IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences · 2025
Updatable encryption (UE) is a special type of symmetric-key encryption (SKE) that allows a third party to update ciphertexts while protecting plaintexts. Alamati et al. (CRYPTO 2019) showed a curious connection between UE and public-key encryption (PKE) that PKE can be constructed from UE. This implication result is somewhat surprising since it is well-known that PKE cannot be constructed from (ordinary) SKE in a black-box manner.