34,531 research outputs found
On the Selection of Pairing-Friendly Groups
We propose a simple algorithm to select group generators suitable for pairing-based cryptosystems. The selected parameters are shown to favor implementations of the Tate pairing that are at once conceptually simple and efficient, with an observed performance about 2 to 10 times better than previously reported implementations, depending on the embedding degree. Our algorithm has beneficial side effects: various non-pairing operations become faster, and bandwidth may be saved
TNFS Resistant Families of Pairing-Friendly Elliptic Curves
Recently there has been a significant progress on the tower number field sieve (TNFS) method, reducing the complexity of the discrete logarithm problem (DLP) in finite field extensions of composite degree. These new variants of the TNFS attacks have a major impact on pairing-based cryptography and particularly on the selection of the underlying elliptic curve groups and extension fields. In this paper we revise the criteria for selecting pairing-friendly elliptic curves considering these new TNFS attacks in finite extensions of composite embedding degree. Additionally we update the criteria for finite extensions of prime degree in order to meet today’s security requirements
Solving discrete logarithms on a 170-bit MNT curve by pairing reduction
Pairing based cryptography is in a dangerous position following the
breakthroughs on discrete logarithms computations in finite fields of small
characteristic. Remaining instances are built over finite fields of large
characteristic and their security relies on the fact that the embedding field
of the underlying curve is relatively large. How large is debatable. The aim of
our work is to sustain the claim that the combination of degree 3 embedding and
too small finite fields obviously does not provide enough security. As a
computational example, we solve the DLP on a 170-bit MNT curve, by exploiting
the pairing embedding to a 508-bit, degree-3 extension of the base field.Comment: to appear in the Lecture Notes in Computer Science (LNCS
Still Wrong Use of Pairings in Cryptography
Several pairing-based cryptographic protocols are recently proposed with a
wide variety of new novel applications including the ones in emerging
technologies like cloud computing, internet of things (IoT), e-health systems
and wearable technologies. There have been however a wide range of incorrect
use of these primitives. The paper of Galbraith, Paterson, and Smart (2006)
pointed out most of the issues related to the incorrect use of pairing-based
cryptography. However, we noticed that some recently proposed applications
still do not use these primitives correctly. This leads to unrealizable,
insecure or too inefficient designs of pairing-based protocols. We observed
that one reason is not being aware of the recent advancements on solving the
discrete logarithm problems in some groups. The main purpose of this article is
to give an understandable, informative, and the most up-to-date criteria for
the correct use of pairing-based cryptography. We thereby deliberately avoid
most of the technical details and rather give special emphasis on the
importance of the correct use of bilinear maps by realizing secure
cryptographic protocols. We list a collection of some recent papers having
wrong security assumptions or realizability/efficiency issues. Finally, we give
a compact and an up-to-date recipe of the correct use of pairings.Comment: 25 page
Heuristics on pairing-friendly abelian varieties
We discuss heuristic asymptotic formulae for the number of pairing-friendly
abelian varieties over prime fields, generalizing previous work of one of the
authors arXiv:math1107.0307Comment: Pages 6-7 rewritten, other minor changes mad
Refinements of Miller's Algorithm over Weierstrass Curves Revisited
In 1986 Victor Miller described an algorithm for computing the Weil pairing
in his unpublished manuscript. This algorithm has then become the core of all
pairing-based cryptosystems. Many improvements of the algorithm have been
presented. Most of them involve a choice of elliptic curves of a \emph{special}
forms to exploit a possible twist during Tate pairing computation. Other
improvements involve a reduction of the number of iterations in the Miller's
algorithm. For the generic case, Blake, Murty and Xu proposed three refinements
to Miller's algorithm over Weierstrass curves. Though their refinements which
only reduce the total number of vertical lines in Miller's algorithm, did not
give an efficient computation as other optimizations, but they can be applied
for computing \emph{both} of Weil and Tate pairings on \emph{all}
pairing-friendly elliptic curves. In this paper we extend the Blake-Murty-Xu's
method and show how to perform an elimination of all vertical lines in Miller's
algorithm during Weil/Tate pairings computation on \emph{general} elliptic
curves. Experimental results show that our algorithm is faster about 25% in
comparison with the original Miller's algorithm.Comment: 17 page
Individual Employment Rights Arbitration in the United States: Actors and Outcomes
The authors examine disposition statistics from employment arbitration cases administered over an 11-year period by the American Arbitration Association (AAA) to investigate the process of dispute resolution in this new institution of employment relations. They investigate the predictors of settlement before the arbitration hearing and then estimate models for the likelihood of employee wins and damage amounts for the 2,802 cases that resulted in an award. Their findings show that larger-scale employers who are involved in more arbitration cases tend to have higher win rates and have lower damage awards made against them. This study also provides evidence of a significant repeat employer-arbitrator pair effect; employers that use the same arbitrator on multiple occasions win more often and have lower damages awarded against them than do employers appearing before an arbitrator for the first time. The authors find that self-represented employees tend to settle cases less often, win cases that proceed to a hearing less often, and receive lower damage awards. Female arbitrators and experienced professional labor arbitrators render awards in favor of employees less often than do male arbitrators and other arbitrators
A short-list of pairing-friendly curves resistant to Special TNFS at the 128-bit security level
https://www.iacr.org/docs/pub_2013-16.htmlThis paper is the IACR version. It can be made freely available on the homepages of authors, on their employer's institutional page, and in non-commercial archival repositories such as the Cryptology ePrint Archive, ArXiv/CoRR, HAL, etc.International audienceThere have been notable improvements in discrete logarithm computations in finite fields since 2015 and the introduction of the Tower Number Field Sieve algorithm (TNFS) for extension fields. The Special TNFS is very efficient in finite fields that are target groups of pairings on elliptic curves, where the characteristic is special (e.g.~sparse). The key sizes for pairings should be increased, and alternative pairing-friendly curves can be considered.We revisit the Special variant of TNFS for pairing-friendly curves. In this case the characteristic is given by a polynomial of moderate degree (between 4 and 38) and tiny coefficients, evaluated at an integer (a seed). We present a polynomial selection with a new practical trade-off between degree and coefficient size. As a consequence, the security of curves computed by Barbulescu, El~Mrabet and Ghammam in 2019 should be revised: we obtain a smaller estimated cost of STNFS for all curves except BLS12 and BN.To obtain TNFS-secure curves, we reconsider the Brezing--Weng generic construction of families of pairing-friendly curves and estimate the cost of our new Special TNFS algorithm for these curves. This improves on the work of Fotiadis and Konstantinou, Fotiadis and Martindale, and Barbulescu, El~Mrabet and Ghammam. We obtain a short-list of interesting families of curves that are resistant to the Special TNFS algorithm, of embedding degrees 10 to 16 for the 128-bit security level. We conclude that at the 128-bit security level, BLS-12 and Fotiadis--Konstantinou--Martindale curves with over a 440 to 448-bit prime field seem to be the best choice for pairing efficiency. We also give hints at the 192-bit security level
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