|dc.description.abstract||Secure Multi-party Computation (MPC) with small population has drawn focus specifically
due to customization in techniques and resulting efficiency that the constructions can offer.
Practically efficient constructions have been witnessed in the setting of both honest majority
and dishonest majority. In this work, we investigate the efficiency of a wide range of security
notions in the small party domain with 5 parties and 4 parties. Being constant-round, our
protocols are best suited for real-time, high latency networks such as the Internet. All our
constructions are backed with experimental results.
In the setting of ve parties with honest majority, we present efficient constructions with
unanimous abort (where either all honest parties obtain the output or none of them do) and
fairness (where the adversary obtains its output only if all honest parties also receive it) in
a minimal setting of pairwise-private channels. With the presence of an additional broadcast
channel (known to be necessary), we present a construction with the strongest security of
guaranteed output delivery (where any adversarial behaviour cannot prevent the honest parties
from receiving the output). The broadcast communication is minimal and independent of circuit
size. In terms of performance (communication and run time), our protocols incur minimal
overhead over the best known selective abort protocol of Chandran et al. (ACM CCS 2016)
while retaining their round complexity. Further, our protocols for fairness and unanimous abort
can be extended to n-parties with at most
n corruptions, similar to Chandran et al.
In the setting of four parties, surpassing the traditional honest majority model, we achieve
stronger security goals in a mixed model where minority of the parties are actively corrupt
and additionally some parties are passively corrupt, thus giving an overall dishonest majority.
We present the first efficient constructions that tolerate a mixed adversary corrupting 1 party
actively and 1 party passively and achieve the security goals of guaranteed output delivery and
fairness. Our constructions adhere to the feasibility result of Hirt et al. (CRYPTO'13).
Going beyond the most popular honest-majority setting of three parties with one corruption,
our results demonstrate feasibility of attaining stronger security notions at an expense not too
far from the least desired security of selective abort.||en_US
|dc.rights||I grant Indian Institute of Science the right to archive and to make available my thesis or dissertation in whole or in part in all forms of media, now hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part
of this thesis or dissertation||en_US
|dc.subject.classification||Research Subject Categories::TECHNOLOGY::Information technology::Computer science::Computer science||en_US
|dc.title||Practically Efficient Secure Small Party Computation over the Internet||en_US
|dc.degree.grantor||Indian Institute of Science||en_US