Paper 2018/237
On Tightly Secure Non-Interactive Key Exchange
Julia Hesse and Dennis Hofheinz and Lisa Kohl
Abstract
We consider the reduction loss of security reductions for non-interactive key exchange (NIKE) schemes. Currently, no tightly secure NIKE schemes exist, and in fact Bader et al. (EUROCRYPT 2016) provide a lower bound (of O(n^2), where n is the number of parties an adversary interacts with) on the reduction loss for a large class of NIKE schemes. We offer two results: the first ``somewhat tight'' NIKE scheme (with a reduction loss of n/2) that circumvents the lower bound of Bader et al., but is of course still far from tightly secure. Second, we provide a generalization of Bader et al.'s lower bound to a larger class of NIKE schemes (that also covers our NIKE scheme), with an adapted lower bound of n/2 on the reduction loss. Hence, in that sense, the reduction for our NIKE scheme is optimal.
Metadata
- Available format(s)
- Category
- Public-key cryptography
- Publication info
- Preprint. MINOR revision.
- Keywords
- non-interactive key exchangehash proof systemstight security
- Contact author(s)
- lisa kohl @ kit edu
- History
- 2018-06-11: revised
- 2018-03-05: received
- See all versions
- Short URL
- https://ia.cr/2018/237
- License
-
CC BY