On Actively Secure Fine-grained Access Structures from Isogeny Assumptions [article]

Philipp Muth, Fabio Campos
2021 IACR Cryptology ePrint Archive  
We present an actively secure threshold scheme in the setting of Hard Homogenous Spaces (HHS) which allows fine-grained access structures. More precisely, we elevate a given passively secure isogeny based threshold scheme to an actively secure setting. We prove the active security and simulatability of our advanced schemes. By defining some characterising properties, we are able to expand the range of secret sharing schemes which support the given scheme. Furthermore, we show that Shamir's
more » ... e has our generalised properties, and thereby our approach truly represents a less restrictive generalisation.
dblp:journals/iacr/MuthC21 fatcat:crvcpawq4zg2ndua5c4dg47mxm