Congressos (Departament de Tecnologies de la Informació i les Comunicacions)http://hdl.handle.net/10230/161162019-08-22T09:31:29Z2019-08-22T09:31:29ZIdentification of potential Music Information Retrieval technologies for computer-aided jingju singing trainingGong, RongSerra, Xavierhttp://hdl.handle.net/10230/422382019-08-14T01:30:55Z2017-01-01T00:00:00ZIdentification of potential Music Information Retrieval technologies for computer-aided jingju singing training
Gong, Rong; Serra, Xavier
Music Information Retrieval (MIR) technologies have been proven useful in assisting western
classical singing training. Jingju (also known as Beijing or Peking opera) singing is different
from western singing in terms of most of the perceptual dimensions, and the trainees are
taught by using mouth/heart method. In this paper, we first present the training method used
in the professional jingju training classroom scenario and show the potential benefits of
introducing the MIR technologies into the training process. The main part of this paper
dedicates to identify the potential MIR technologies for jingju singing training. To this intent,
we answer the question: how the jingju singing tutors and trainees value the importance of
each jingju musical dimension—intonation, rhythm, loudness, tone quality and
pronunciation? This is done by (i) classifying the classroom singing practices, tutor's verbal
feedbacks into these 5 dimensions, (ii) surveying the trainees. Then, with the help of the
music signal analysis, a finer inspection on the classroom practice recording examples
reveals the detailed elements in the training process. Finally, based on the above analysis,
several potential MIR technologies are identified and would be useful for the jingju singing
training.
Comunicació presentada a: 5th China Conference on Sound and Music Technology - Chinese Traditional Music Technology Session celebrada el 21 de novembre de 2017 a Suzhou, Xina.
2017-01-01T00:00:00ZPolynomial spaces: a new framework for composite to-prime-order transformationsHerold, GottfriedHesse, JuliaHofheinz, DennisRàfols, CarlaRupp, Andyhttp://hdl.handle.net/10230/422292019-08-02T01:31:00Z2014-01-01T00:00:00ZPolynomial spaces: a new framework for composite to-prime-order transformations
Herold, Gottfried; Hesse, Julia; Hofheinz, Dennis; Ràfols, Carla; Rupp, Andy
At Eurocrypt 2010, Freeman presented a framework to convert
cryptosystems based on composite-order groups into ones that use
prime-order groups. Such a transformation is interesting not only from
a conceptual point of view, but also since for relevant parameters, operations
in prime-order groups are faster than composite-order operations
by an order of magnitude. Since Freeman's work, several other works
have shown improvements, but also lower bounds on the efficiency of
such conversions.
In this work, we present a new framework for composite-to-prime-order
conversions. Our framework is in the spirit of Freeman's work; however,
we develop a different, \polynomial" view of his approach, and
revisit several of his design decisions. This eventually leads to significant
e ciency improvements, and enables us to circumvent previous
lower bounds. Specifically, we show how to verify Groth-Sahai proofs in
a prime-order environment (with a symmetric pairing) almost twice as
efficiently as the state of the art.
We also show that our new conversions are optimal in a very broad sense.
Besides, our conversions also apply in settings with a multilinear map,
and can be instantiated from a variety of computational assumptions
(including, e.g., the k-linear assumption).
Comunicació presentada a: CRYPTO 2014. 34th Annual Cryptology Conference, celebrada a Santa Barbara, Califòrnia, Estats Units d'Amèrica, del 17 al 21 d'agost de 2014
2014-01-01T00:00:00ZIdentity-based lossy trapdoor functions: new definitions, hierarchical extensions, and implicationsEscala, AlexHerranz, JavierLibert, BenoîtRàfols, Carlahttp://hdl.handle.net/10230/422282019-08-02T01:30:53Z2014-01-01T00:00:00ZIdentity-based lossy trapdoor functions: new definitions, hierarchical extensions, and implications
Escala, Alex; Herranz, Javier; Libert, Benoît; Ràfols, Carla
Lossy trapdoor functions, introduced by Peikert and Waters
(STOC’08), have received a lot of attention in the last years,
because of their wide range of applications. The notion has been recently
extended to the identity-based setting by Bellare et al. (Eurocrypt’12).
An identity-based trapdoor function (IB-TDF) satisfying the lossy property
introduced by Bellare et al. can be used to construct other cryptographic
primitives in the identity-based setting: encryption schemes
with semantic security under chosen-plaintext attacks, deterministic encryption
schemes, and hedged encryption schemes that maintain some
security when messages are encrypted using randomness of poor quality.
However, the constructed primitives can be proved secure only against
selective adversaries who select the target identity upfront.
Our first contribution is an alternative definition for the lossiness
of an identity-based trapdoor function. We prove that an IB-TDF
satisfying the new property can be used to construct all the aforementioned
primitives, in the identity-based setting, with security against
adaptive adversaries. We further consider the new definition and its implications
in the more general scenario of hierarchical identity-based
cryptography, which has proved very useful both for practical applications
and to establish theoretical relations with other cryptographic
primitives (including encryption with chosen-ciphertext security or with
forward-security).
As a second contribution, we describe a pairing-based hierarchical
IB-TDF satisfying the new definition of lossiness against either selective
or, for hierarchies of constant depth, adaptive adversaries. This is
also the first example of hierarchical trapdoor functions based on traditional
(i.e., non-lattice-related) number theoretic assumptions. As a
direct consequence of our two contributions, we obtain a hierarchical
identity-based (HIB) encryption scheme with chosen-plaintext security,
a HIB deterministic encryption scheme and a HIB hedged encryption
scheme, all of them with security against adaptive adversaries.
Comunicació presentada a: PKC 2014 17th International Conference on Practice and Theory in Public-Key Cryptography, celebrada a Buenos Aires, Argentina, del 26 al 28 de març de 2014
2014-01-01T00:00:00ZStretching Groth-Sahai: NIZK proofs of partial satisfiabilityRàfols, Carlahttp://hdl.handle.net/10230/422272019-08-02T01:31:02Z2015-01-01T00:00:00ZStretching Groth-Sahai: NIZK proofs of partial satisfiability
Ràfols, Carla
Groth, Ostrovsky and Sahai constructed a non-interactive Zap for NP-languages by observing
that the common reference string of their proof system for circuit satisfiability admits
what they call correlated key generation. The latter means that it is possible to create from
scratch two common reference strings in such a way that it can be publicly verified that
at least one of them guarantees perfect soundness while it is computationally infeasible to
tell which one. Their technique also implies that it is possible to have NIWI Groth-Sahai
proofs for certain types of equations over bilinear groups in the plain model. We extend the
result of Groth, Ostrovsky and Sahai in several directions. Given as input some predicate
P computable by some monotone span program over a finite field, we show how to generate
a set of common reference strings in such a way that it can be publicly verified that
the subset of them which guarantees perfect soundness is accepted by the span program.
We give several different
avors of the technique suitable for different applications scenarios
and different equation types. We use this to stretch the expressivity of Groth-Sahai proofs
and construct NIZK proofs of partial satisfiability of sets of equations in a bilinear group
and more efficient Groth-Sahai NIWI proofs without common reference string for a larger
class of equation types. Finally, we apply our results to significantly reduce the size of the
signatures of the ring signature scheme of Chandran, Groth and Sahai or to have a more
efficient proof in the standard model that a commitment opens to an element of a public list.
Comunicació presentada a: 12th Theory of Cryptography Conference, TCC 2015, celebrada del 23 al 25 de març de 2015 a Varsòvia, Polònia.
2015-01-01T00:00:00Z