Authors:
Matluba Khodjaeva
1
and
Giovanni Di Crescenzo
2
Affiliations:
1
CUNY John Jay College of Criminal Justice, NY, U.S.A.
;
2
Peraton Labs, Basking Ridge, NJ, U.S.A.
Keyword(s):
Cryptography, Secure Delegation, Pairings, Elliptic Curves.
Abstract:
Many public-key cryptosystems use pairings as important primitive operations. To expand the applicability of these solutions to computationally weaker devices, it has been advocated that a computationally weaker client delegates such primitive operations to a computationally stronger server. Important requirements for such delegation protocols include privacy of the client’s pairing inputs and security of the client’s output, in the sense of detecting, except for very small probability, any malicious server’s attempt to convince the client of an incorrect pairing result. Except for less than a handful of results, all single-server delegation protocols in the literature are structured into an offline phase, where precomputation can be performed, and an online phase, where the client has resource constraints. Designing single-server delegation protocols without precomputation is naturally harder. In this paper, we show that the computation of a pairing with non-private inputs can be ef
ficiently delegated to a single server, without need for precomputation. We also discuss the failure of a previously published attempt, and note the inefficiency of natural extensions of our protocol to more demanding input cases.
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