A novel threshold changeable secret sharing scheme

A(t,n)threshold secret sharing scheme is a fundamental tool in many security applications such as cloud computing and multiparty computing.In conventional threshold secret sharing schemes,like Shamir’s scheme based on a univariate polynomial,additional communication key share scheme is needed for shareholders to protect the secrecy of their shares if secret reconstruction is performed over a network.In the secret reconstruction,the threshold changeable secret sharing(TCSS)allows the threshold to be a dynamic value so that if some shares have been compromised in a given time,it needs more shares to reconstruct the secret.Recently,a new secret sharing scheme based on a bivariate polynomial is proposed in which shares generated initially by a dealer can be used not only to reconstruct the secret but also to protect the secrecy of shares when the secret reconstruction is performed over a network.In this paper,we further extend this scheme to enable it to be a TCSS without any modification.Our proposed TCSS is dealer-free and non-interactive.Shares generated by a dealer in our scheme can serve for three purposes,(a)to reconstruct a secret;(b)to protect the secrecy of shares if secret reconstruction is performed over a network;and(c)to enable the threshold changeable property.     

Lightweight and flexible key distribution schemes for secure group communications

Wireless Networks - Key distribution is one of the most fundamental cryptographic primitives that can establish secure group communications in both centralized and distributed networks. A one-time...     

Simultaneous translational temperature measurements of different atomic species in plasma flows using scanning Fabry-Perot interferometry

A revised scientific instrument to measure simultaneously kinetic temperatures of different atoms from their optical emission profile is reported. Emission lines are simultaneously detected using one single scanning Fabry-Perot-interferometer (FPI) for a combined spectroscopic setup to acquire different emission lines simultaneously. The setup consists in a commercial Czerny-Turner spectrometer configuration which is combined with a scanning Fabry-Perot interferometer. The fast image acquisition mode of an intensified charge coupled device camera allows the detection of a wavelength interval of interest continuously while acquiring the highly resolved line during the scan of the FPI ramp. Results using this new setup are presented for the simultaneous detection of atomic nitrogen and oxygen in a high enthalpy air plasma flow as used for atmospheric re-entry research and their respective kinetic temperatures derived from the measured line profiles. The paper presents the experimental setup, the calibration procedure, and an exemplary result. The determined temperatures are different, a finding that has been published so far as due to a drawback of the experimental setup of sequential measurements, and which has now to be investigated in more detail.     

Fuzzy logic as a basis for reusing task-based specifications

In this paper, we propose an approach to reusing requirements specification, called task-based specifications in conceptual graphs (TBCG). In TBCG, task-based specification methodology is used to serve as the mechanism to structure the knowledge captured in conceptual models, and conceptual graphs are adopted as the formalism to express requirements specification. TBCG provides several mechanisms to facilitate the reuse of formal specifications: a contextual retrieval mechanism to support context-sensitive specifications retrieval and incremental context acquisition, a graph matching mechanism to compute the similarity between two graphs based on the semantic match and fuzzy logic, and a paraphraser to serve as an explanation mechanism for the retrieval specifications. ©1999 John Wiley & Sons, Inc.     

医疗大数据隐私保护多关键词范围搜索方案

随着医疗信息系统的急速发展,基于医疗云的信息系统将大量电子健康记录(EHRs)存储在医疗云系统中,利用医疗云强大的存储能力和计算能力对EHRs数据进行安全与统一的管理.尽管传统加密机制可以保证医疗数据在半诚实云服务器中的机密性,但对加密后的EHRs数据执行安全、快速、有效的范围搜索,仍是一个有待解决的关键问题.提出一种...     

UMKESS: user-oriented multi-group key establishments using secret sharing

Wireless Networks - With the rapid development of group-oriented services, there are more and more multi-group communications in which users may join multiple group communications simultaneously....     

Centralized Group Key Establishment Protocol without a Mutually Trusted Third Party

The type of centralized group key establishment protocols is the most commonly used one due to its efficiency in computation and communication. A key generation center (KGC) in this type of protocols acts as a server to register users initially. Since the KGC selects a group key for group communication, all users must trust the KGC. Needing a mutually trusted KGC can cause problem in some applications. For example, users in a social network cannot trust the network server to select a group key for a secure group communication. In this paper, we remove the need of a mutually trusted KGC by assuming that each user only trusts himself. During registration, each user acts as a KGC to register other users and issue sub-shares to other users. From the secret sharing homomorphism, all sub-shares of each user can be combined into a master share. The master share enables a pairwise shared key between any pair of users. A verification of master shares enables all users to verify their master shares are generated consistently without revealing the master shares. In a group communication, the initiator can become the server to select a group key and distribute it to each other user over a pairwise shared channel. Our design is unique since the storage of each user is minimal, the verification of master shares is efficient and the group key distribution is centralized. There are public-key based group key establishment protocols without a trusted third party. However, these protocols can only establish a single group key. Our protocol is a non-public-key solution and can establish multiple group keys which is computationally efficient.     

Nanoporous Gold Biointerfaces: Modifying Nanostructure to Control Neural Cell Coverage and Enhance Electrophysiological Recording Performance

Nanostructured neural interface coatings have significantly enhanced recording fidelity in both implantable and in vitro devices. As such, nanoporous gold (np‐Au) has shown promise as a multifunctional neural interface coating due, in part, to its ability to promote nanostructure‐mediated reduction in astrocytic surface coverage while not affecting neuronal coverage. The goal of this study is to provide insight into the mechanisms by which the np‐Au nanostructure drives the differential response of neurons versus astrocytes in an in vitro model. Utilizing microfabricated libraries that display varying feature sizes of np‐Au, it is demonstrated that np‐Au influences neural cell coverage through modulating focal adhesion formation in a feature size‐dependent manner. The results here show that surfaces with small (≈30 nm) features control astrocyte spreading through inhibition of focal adhesion formation, while surfaces with large (≈170 nm and greater) features control astrocyte spreading through other mechanotransduction mechanisms. This cellular response combined with lower electrical impedance of np‐Au electrodes significantly enhances the fidelity and stability of electrophysiological recordings from cortical neuron‐glia co‐cultures relative to smooth gold electrodes. Finally, by leveraging the effect of nanostructure on neuronal versus glial cell attachment, the use of laser‐based nanostructure modulation is demonstrated for selectively patterning neurons with micrometer spatial resolution.     

Contract signature in e-commerce

In this paper, we propose a notion of contract signature used in e-commerce applications. We propose a contract signature scheme based on the discrete logarithm assumption. The contract signature scheme adopts a digital multi-signature scheme in public-key cryptography to facilitate fair signature exchange over network. This proposed solution allows multiple signers of a contract signature to exchange their partial signatures which are fully ambiguous for any third party (i.e., 1 out of ∞ ambiguity) to construct a valid contract signature. In case any signer releases the partial signature to others, the signer does not bind to the contract.