Our work, titled Hollow LWE: A New Spin — Unbounded Updatable Encryption from LWE and PCE, is now available on ePrint and will be presented at Eurocrypt 2025 in Madrid in May. It is joint work with…| malb::blog
Updatable public-key encryption (UPKE) allows anyone to update a public key while simultaneously producing an update token, given which the secret key holder could consistently update the secret key. Furthermore, ciphertexts encrypted under the old public key remain secure even if the updated secret key is leaked -- a property much desired in secure messaging. All existing lattice-based constructions of UPKE update keys by a noisy linear shift. As the noise accumulates, these schemes either r...| IACR Cryptology ePrint Archive