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1

Star-Topological Encryption : Talking to the Sever but Hiding Identities to Others

Li J., Wang L., Niu X., Gu L., Qu Z.

Fundamenta Informaticae

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2018

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Vol. 157, nr 1/2

29--46

EN

In this paper, we propose the notion of Star-Topological encryption that enables some clients confidentially talking to a server but without revealing their identities to others. Then, an encryption scheme is constructed to achieve this cryptosystem based on non-abelian groups. The proposal realizes identity-based encryption and identity authenticity, simultaneously. In this encryption system, both the encryptions and decryptions of two sides of the communications are relying on secret key. Therefore, the encryption/decryption algorithms employ the idea of symmetric key cryptosystem. Meanwhile, the client’s decryption key is generated by taking client’s identity and server’s master secret key as input. Therefore, our encryption scheme can be viewed as an identity-based encryption in Symmetric Key Cryptosystem. Furthermore, the security of the scheme is based on the intractability of factorization search problem over non-abelian algebraic structures. A matrix group over group ring is suggested and an algorithm of computing the inverse of an invertible group ring element is given. Finally, we discuss that our cryptosystem is secure against determinant attacks and quantum attacks.

2

An Efficient Construction of Quantum Attack Resistant Proxy Re-Encryption Based on (Semi) group Factorization Problems

Wang L., Li J., Gu L., Yan J., Qu Z.

Fundamenta Informaticae

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2018

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Vol. 157, nr 1/2

47--62

EN

Proxy re-encryption (PRE) enables a semi-trusted proxy to transfer Alice's secrets into Bob's secrets but without seeing the secrets. This functionality is very interesting for making balance between the information confidentiality and the mutual accessibility in various scenarios such as public cloud storage systems. During the past decades, many smart PRE schemes were built based on intractability assumptions such as integer factorization problems (IFP) and discrete logarithm problems (DLP). However, Shor's efficient quantum algorithms for IFP and DLP stand great threats towards the security baseline of these schemes. Enlightened by Gu et al.'s recent work on resisting known quantum attacks, we propose an efficient PRE scheme based on the intractability of the (semi)group factorization problems in this paper. The security of the proposed scheme is analyzed according to some heuristic attacks. Moreover, a special instantiation technique is present in detail, and some illustrations are provided for manifesting the effectiveness and efficiency of the proposed methodology.

3

Influence of Bi3+ content on photoluminescence of InNbO4:Eu3+,Bi3+ for white light-emitting diodes

Tang A., Gu L., Shao F., Liu X., Zhao Y., Chen H., Zhang H.

Materials Science Poland

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2017

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Vol. 35, No. 2

435--439

EN

A series of red-emitting phosphors InNbO4:Eu3+,Bi3+ was prepared by a high temperature solid-state reaction. The structure, size distribution and luminescence properties of the phosphors were respectively characterized by X-ray diffraction (XRD), laser particle size and molecular fluorescence spectrometer. The XRD results indicate that the phase-pure samples have been obtained and the crystal structure of the host has not changed under the Eu3+ and Bi3+ co-doping. The test of size distribution shows that the phosphor has a normal size distribution. The excitation spectra illustrate that the dominant sharp peaks are located at 394 nm (7F0→5L6) and 466 nm (7F0→5D2). Meanwhile, the emission spectra reveal that the phosphors excited by the wavelength of 394 nm or 466 nm have an intense red-emission line at 612 nm owing to the 5D0→(7F2 transition of Eu3+. Bi3+ doping has not changed the peak positions except the photoluminescence intensity. The emission intensity is related to Bi3+ concentration, and it is up to the maximum when the Bi3+-doping concentration is 4 mol%. Due to good photoluminescence properties of the phosphor, the InNbO4:0.04Eu3+,0.04Bi3+ may be used as a red component for white light-emitting diodes.

4

Luminescence properties of novel red-emitting phosphor InNb1-xPxO4:Eu3+ for white light emitting-diodes

Tang A., Ma T., Gu L., Zhao Y., Zhang J., Zhang H., Shao F., Zhang H.

Materials Science Poland

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2015

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Vol. 33, No. 2

331--334

EN

InNb1-xPxO4: Eu3+ red phosphors were synthesized by solid-state reaction and their luminescence properties were also studied through photoluminescence spectra. The excitation and emission spectra make it clear that the as-prepared phosphors can be effectively excited by near-ultraviolet (UV) 394 nm light and blue 466 nm light to emit strong red light located at 612 nm, due to the Eu3+ transition of D-5(0) -> F-7(2). The luminescence intensity is dependent on phosphorus content, and it achieves the maximum at x = 0.4. Excessive phosphorus in the phosphors can result in reduction of luminescence intensity owing to concentration quenching. With the increasing content of phosphorus, the phosphors are prone to emit pure red light. This shows that the InNb1.6P0.O-4(4):0.04Eu(3+) phosphor may be a potential candidate as a red component for white light emitting-diodes.

5

Geometric Model for Multi-axial Warp-knitted Fabric Based on NURBS

Jiang G, Gu L, Cong H L, Miao X H, Zhang A, Gao Z

Fibres & Textiles in Eastern Europe

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2014

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Vol. 22, no. 3 (105)

91--97

EN

Based on studying the constitution of yarn system and the geometric modality of relevant yarns in the multi-axial warp-knitted structure, 3D solid models of the loop yarns, insertion yarns and chopped strand mat in modern multi-axial warp-knitted fabrics were built to reflect the geometric structures of the three items by using NURBS curves and the principle of curved surfaces. Besides, OpenGL was employed to explore the corresponding 3D computer simulation system under the condition of VC++.NET, which could simulate the geometric model of multi-axial warp-knitted fabric. Meanwhile, through the selection of the unit cell of the fabric, the unit cell model of modern multi-axial warp-knitted fabric with chopped strand mat was developed and the relation between geometric parameters and process variables was deduced. The theoretical fibre volume fraction formula of modern multi-axial warp-knitted fabric with chopped strand mat was obtained as well. Furthermore, by using different specifications of fabric as samples, theoretical and experimental values of the fibre volume fraction were compared. The results revealed that there was good agreement between the theoretical and experimental values, which proved that the model was scientific and practical.

PL

Na podstawie badań struktury systemu przędz i geometrycznej modalności odpowiednich przędz w wieloosiowej dzianej strukturze osnowowej opracowano modele brył 3D przędz pętli, przędz wprowadzanych i struktur z włókien odcinkowych we współczesnych wieloosiowych dzianinach osnowowych w celu zobrazowania ich geometrycznych struktur dzięki zastosowaniu krzywych NURBS i reguł dotyczących zakrzywionych powierzchni. Oprócz tego zastosowano program OpenGL dla zbadania systemu symulacji komputerowej 3D przy warunkach VC++.NET, co pozwala na symulację geometrycznego modelu wieloosiowych dzianin osnowowych. Jednocześnie dzięki selekcji komórki podstawowej dzianiny opracowano model takiej komórki podstawowej dla konfiguracji wcześniej opisanej. Określono również zależności pomiędzy parametrami geometrycznymi a zmiennymi procesowymi. Uzyskano teoretyczną objętość włókien, następnie korzystając ze specyfikacji różnego rodzaju próbek określono zależności pomiędzy teoretycznymi i eksperymentalnymi wartościami objętości poszczególnych frakcji włókien. Wyniki wykazały, że istnieje zgodność pomiędzy teoretycznymi i eksperymentalnymi wartościami, co oznacza, że opracowany model jest naukowo uzasadniony i możliwy do stosowania w praktyce.