scholarly journals Secret Sharing Schemes on Sparse Homogeneous Access Structures with Rank Three

10.37236/1825 ◽  
2004 ◽  
Vol 11 (1) ◽  
Author(s):  
Jaume Martí-Farré ◽  
Carles Padró
Keyword(s):  
Secret Sharing ◽  
Access Structure ◽  
Open Problems ◽  
Access Structures ◽  
The Family ◽  
Ideal Access Structures ◽  
Optimal Information ◽  
Made In ◽  
The Ideal

One of the main open problems in secret sharing is the characterization of the ideal access structures. This problem has been studied for several families of access structures with similar results. Namely, in all these families, the ideal access structures coincide with the vector space ones and, besides, the optimal information rate of a non-ideal access structure is at most $2/3$. An access structure is said to be $r$-homogeneous if there are exactly $r$ participants in every minimal qualified subset. A first approach to the characterization of the ideal $3$-homogeneous access structures is made in this paper. We show that the results in the previously studied families can not be directly generalized to this one. Nevertheless, we prove that the equivalences above apply to the family of the sparse $3$-homogeneous access structures, that is, those in which any subset of four participants contains at most two minimal qualified subsets. Besides, we give a complete description of the ideal sparse $3$-homogeneous access structures.

The Optimal Information Rates of the Graph Access Structures on Seven Participants

2013 ◽  
Vol 859 ◽  
pp. 596-601
Author(s):  
Zhi Hui Li ◽  
Yun Song ◽  
Yong Ming Li
Keyword(s):  
Secret Sharing ◽  
Information Rate ◽  
Secret Sharing Scheme ◽  
Access Structure ◽  
Open Problems ◽  
Information Rates ◽  
Access Structures ◽  
Sharing Scheme ◽  
Optimal Information ◽  
Graph Access

The information rate is an important metric of the performance of a secret-sharing scheme. In this paper, we deal with determining the exact values for the optimal information rates of the six graph access structures and improving the information rate of a graph access structure on seven participants, which remained as open problems in Song's and Wang's paper([1,2]). We prove that the optimal information rate for each of the six graph access structures is equal to 4/7

scholarly journals Viruses and Virus Diseases of Rubus

Plant Disease ◽  
2013 ◽  
Vol 97 (2) ◽  
pp. 168-182 ◽  
Author(s):  
Robert R. Martin ◽  
Stuart MacFarlane ◽  
Sead Sabanadzovic ◽  
Diego Quito ◽  
Bindu Poudel ◽  
...  
Keyword(s):  
Far East ◽  
Fruit Production ◽  
Detection Methods ◽  
Center Of Origin ◽  
The Family ◽  
Production Stages ◽  
Rubus Species ◽  
Polymerase Chain ◽  
Made In

Blackberry and raspberry are members of the family Rosaceae. They are classified in the genus Rubus, which comprises hundreds of species and has a center of origin in the Far East. Rubus is divided into 15 subgenera with blackberries classified in the Rubus (formerly Eubatus) and raspberries in the Idaeobatus subgenera. Rubus species are propagated vegetatively and are subject to infection by viruses during development, propagation, and fruit production stages. Reports of initial detection and symptoms of more than 30 viruses, virus-like diseases, and phytoplasmas affecting Rubus spp. were reviewed more than 20 years ago. Since the last review on Rubus viruses, significant progress has been made in the molecular characterization of many of the viruses that infect Rubus spp. Currently, reverse transcription–polymerase chain reaction detection methods are available for most of the viruses known to infect Rubus. The goals of this article are to update the knowledge on previously characterized viruses of Rubus, highlight recently described viruses, review the virus-induced symptoms, describe the advances made in their detection, and discuss our knowledge about several virus complexes that cause serious diseases in Rubus. Virus complexes have been identified recently as the major cause of diseases in blackberries and raspberries.

A CHARACTERIZATION OF RECOGNIZABLE PICTURE LANGUAGES

1994 ◽  
Vol 08 (02) ◽  
pp. 501-508 ◽  
Author(s):  
KATSUSHI INOUE ◽  
ITSUO TAKANAMI
Keyword(s):  
Finite Automata ◽  
Two Dimensional ◽  
Open Problems ◽  
Nondeterministic Finite Automata ◽  
Letter Alphabet ◽  
The Family ◽  
On Line ◽  
Picture Languages

This paper first shows that REC, the family of recognizable picture languages in Giammarresi and Restivo,3 is equal to the family of picture languages accepted by two-dimensional on-line tessellation acceptors in Inoue and Nakamura.5 By using this result, we then solve open problems in Giammarresi and Restivo,3 and show that (i) REC is not closed under complementation, and (ii) REC properly contains the family of picture languages accepted by two-dimensional nondeterministic finite automata even over a one letter alphabet.

scholarly journals Spiking Neural P Systems with Weights

2010 ◽  
Vol 22 (10) ◽  
pp. 2615-2646 ◽  
Author(s):  
Jun Wang ◽  
Hendrik Jan Hoogeboom ◽  
Linqiang Pan ◽  
Gheorghe Păun ◽  
Mario J. Pérez-Jiménez
Keyword(s):  
Rational Numbers ◽  
P Systems ◽  
Natural Numbers ◽  
Open Problems ◽  
Spiking Neural P Systems ◽  
Semilinear Sets ◽  
The Family ◽  
Neuron Fire ◽  
Hard Problems

A variant of spiking neural P systems with positive or negative weights on synapses is introduced, where the rules of a neuron fire when the potential of that neuron equals a given value. The involved values—weights, firing thresholds, potential consumed by each rule—can be real (computable) numbers, rational numbers, integers, and natural numbers. The power of the obtained systems is investigated. For instance, it is proved that integers (very restricted: 1, −1 for weights, 1 and 2 for firing thresholds, and as parameters in the rules) suffice for computing all Turing computable sets of numbers in both the generative and the accepting modes. When only natural numbers are used, a characterization of the family of semilinear sets of numbers is obtained. It is shown that spiking neural P systems with weights can efficiently solve computationally hard problems in a nondeterministic way. Some open problems and suggestions for further research are formulated.

scholarly journals A Note on the Generative Power of Axon P Systems

2009 ◽  
Vol 4 (1) ◽  
pp. 92 ◽  
Author(s):  
Xingyi Zhang ◽  
Jun Wang ◽  
Linqiang Pan
Keyword(s):  
P Systems ◽  
Number Generator ◽  
Finite Sets ◽  
Open Problems ◽  
Spiking Neural P Systems ◽  
Generative Power ◽  
Semilinear Sets ◽  
The Family ◽  
Context Free

Axon P systems are a class of spiking neural P systems. In this paper, the axon P systems are used as number generators and language generators. As a language generator, the relationships of the families of languages generated by axon P systems with finite and context-free languages are considered. As a number generator, a characterization of the family of finite sets can be obtained by axon P systems with only one node. The relationships of sets of numbers generated by axon P systems with semilinear sets of numbers are also investigated. This paper partially answers some open problems formulated by H. Chen, T.-O. Ishdorj and Gh. Păun.

scholarly journals An Efficient Compartmented Secret Sharing Scheme Based on Linear Homogeneous Recurrence Relations

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Guoai Xu ◽  
Jiangtao Yuan ◽  
Guosheng Xu ◽  
Zhongkai Dang
Keyword(s):  
Secret Sharing ◽  
Recovery Phase ◽  
Threshold Scheme ◽  
Secret Sharing Schemes ◽  
Access Structure ◽  
Recurrence Sequence ◽  
Access Structures ◽  
Sharing Scheme ◽  
Global Threshold ◽  
Multipartite Access Structures

Multipartite secret sharing schemes are those that have multipartite access structures. The set of the participants in those schemes is divided into several parts, and all the participants in the same part play the equivalent role. One type of such access structure is the compartmented access structure, and the other is the hierarchical access structure. We propose an efficient compartmented multisecret sharing scheme based on the linear homogeneous recurrence (LHR) relations. In the construction phase, the shared secrets are hidden in some terms of the linear homogeneous recurrence sequence. In the recovery phase, the shared secrets are obtained by solving those terms in which the shared secrets are hidden. When the global threshold is t , our scheme can reduce the computational complexity of the compartmented secret sharing schemes from the exponential time to polynomial time. The security of the proposed scheme is based on Shamir’s threshold scheme, i.e., our scheme is perfect and ideal. Moreover, it is efficient to share the multisecret and to change the shared secrets in the proposed scheme.

scholarly journals Message randomization and strong security in quantum stabilizer-based secret sharing for classical secrets

2020 ◽  
Vol 88 (9) ◽  
pp. 1893-1907
Author(s):  
Ryutaroh Matsumoto
Keyword(s):  
Secret Sharing ◽  
Explicit Construction ◽  
Secret Sharing Schemes ◽  
Secret Sharing Scheme ◽  
Access Structure ◽  
Access Structures ◽  
Sharing Scheme ◽  
Randomized Encoding

Abstract We improve the flexibility in designing access structures of quantum stabilizer-based secret sharing schemes for classical secrets, by introducing message randomization in their encoding procedures. We generalize the Gilbert–Varshamov bound for deterministic encoding to randomized encoding of classical secrets. We also provide an explicit example of a ramp secret sharing scheme with which multiple symbols in its classical secret are revealed to an intermediate set, and justify the necessity of incorporating strong security criterion of conventional secret sharing. Finally, we propose an explicit construction of strongly secure ramp secret sharing scheme by quantum stabilizers, which can support twice as large classical secrets as the McEliece–Sarwate strongly secure ramp secret sharing scheme of the same share size and the access structure.

ON THE DEALER'S RANDOMNESS REQUIRED IN PERFECT SECRET SHARING SCHEMES WITH ACCESS STRUCTURES OF CONSTANT RANK

2000 ◽  
Vol 11 (02) ◽  
pp. 263-281
Author(s):  
HUNG-MIN SUN
Keyword(s):  
Secret Sharing ◽  
Upper Bounds ◽  
Secret Sharing Schemes ◽  
Secret Sharing Scheme ◽  
Access Structure ◽  
Constant Rank ◽  
Computational Resource ◽  
Maximum Cardinality ◽  
Access Structures ◽  
Sharing Scheme

A secret sharing scheme is a method which allows a dealer to share a secret among a set of participants in such a way that only qualified subsets of participants can recover the secret. The collection of subsets of participants that can reconstruct the secret in this way is called access structure. The rank of an access structure is the maximum cardinality of a minimal qualified subset. A secret sharing scheme is perfect if unqualified subsets of participants obtain no information regarding the secret. The dealer's randomness is the number of random bits required by the dealer to setup a secret sharing scheme. The efficiency of the dealer's randomness is the ratio between the amount of the dealer's randomness and the length of the secret. Because random bits are a natural computational resource, it is important to reduce the amount of randomness used by the dealer to setup a secret sharing scheme. In this paper, we propose some decomposition constructions for perfect secret sharing schemes with access structures of constant rank. Compared with the best previous results, our constructions have some improved upper bounds on the dealer's randomness and on the efficiency of the dealer's randomness.

scholarly journals Radiation Safety and Future Innovative Diagnostic Modalities

2008 ◽  
Vol 2008 ◽  
pp. 1-3 ◽  
Author(s):  
Christian Radmayr
Keyword(s):  
Radiation Safety ◽  
Ideal Situation ◽  
The Family ◽  
Pediatric Urologist ◽  
Potential Risks ◽  
Diagnostic Modalities ◽  
Definition Of ◽  
Near Future ◽  
Made In ◽  
The Ideal

One must demand an accurate, safe, radiation-free, and noninvasive method for reflux examination as the ideal possibility for reflux screening. Of course the available different imaging modalities are far from this ideal situation, but minimal radiation exposure is indeed a permanent objective. Additionally since all of these studies might be quite stressful to the child and the family, a specially designed and equipped environment is obligatory for the comfort of all involved. An absolute ideal modality in the diagnosis of VUR would be the definition of a certain marker in serum or urine that could identify children with VUR without the need for any interventional screening modality. Therefore more and more efforts have to be made in the future to investigate different markers for this purpose. Since reflux is one of the most frequent congenital conditions pediatric urologist have to deal with potential risks that might lead to renal insufficiency, noninvasive and radiation-free modalities should become the methods of choice, hopefully in the near future.

scholarly journals CSCI/RCPSC Henry Friesen Lecture: The Past and the Future of Neurogenetics

2007 ◽  
Vol 30 (6) ◽  
pp. 269
Author(s):  
Guy Rouleau ◽  
Inge Meijer
Keyword(s):  
Personalized Medicine ◽  
Neurological Diseases ◽  
Causative Gene ◽  
The Past ◽  
The Family ◽  
Clinical Description ◽  
William Osler ◽  
Over Time ◽  
Made In

“To wrest from nature the secrets which have perplexed philosophers in all ages, to track to their sources the cause of disease … these are our ambitions” - Sir William Osler The main aim in neurogenetics is to characterize and understand the genetic causes underlying neurological diseases. Over time, progress has been made in several aspects of neurogenetics. In fact, the evolution of neurogenetics largely resembles the steps currently undertaken when executing a neurogenetics study. These steps include identification of a disease in a family, clinical description and characterization of the family, genetic analysis, and finally understanding the function of the causative gene. Along those lines, the evolution of neurogenetics could be divided in four eras namely the descriptive, the medical technological, the molecular genetics and the personalized medicine era.

Sign in / Sign up

Export Citation Format

Share Document