Security Levels Oriented Deployment Algorithm for Mimic SaaS Cloud

2020 ◽  
Author(s):  
Ni Siyuan ◽  
Hu Hongchao ◽  
Liu Wenyan ◽  
Liang Hao
Keyword(s):  
Security Levels ◽  
Saas Cloud

Cherneha O. B., Chepurnova A. V. COMPARATIVE ANALYSIS OF UKRAINE AND POLAND FOOD SECURITY LEVELS

2019 ◽  
pp. 9-17
Keyword(s):  
Food Security ◽  
Comparative Analysis ◽  
Rural Development ◽  
Agricultural Policy ◽  
Common Agricultural Policy ◽  
Public Spending ◽  
Development Program ◽  
Rural Development Program ◽  
Security Levels ◽  
The Eu

Objective. The purpose of the article is to compare the levels and mechanisms of food security management in Ukraine and Poland, to identify the main factors influencing the processes of its formation and to determine the directions of increasing the level of Ukraine food security. Methods. The scientific results of the study were obtained using the following methods: theoretical generalization and comparison (for the study of meaningful aspects of the definition of «food security»), analysis and synthesis (for comparative analysis of Ukraine and Poland food security levels), abstract-logical method (for establishing the links between the level of economic development of countries and the levels of their food security and determining the directions of increasing the Ukraine level of food security). Results. On the basis of a comparative analysis of Ukraine and Poland food security levels, a significant gap in Ukraine’s provision of food security has been identified. Thus, with respect to all food security components identified by FAO, except for the «use» of sanitary and safe drinking water, Poland has reached far ahead of Ukraine. It has been found that for the period 2012–2018, the value of the Global Food Security Index for Ukraine decreased by 2.1 due to a decrease in the level of affordability and availability of food, while the Polish side increased its position on GFSI by 2.8 due to the increase in affordability and availability of food in the country. It has been found that the decisive influence on the level of food security in Poland, as well as high ranking in the ranking is carried out by the EU Common Agricultural Policy (CAP), the implementation of the Polish Rural Development Program and significant public spending on agriculture. It has been determined that the main directions for improving the level of food security of Ukraine should be: lifting the moratorium on the sale of agricultural land; financing the agri-food sector not only through public spending but also through EU programs; creation and implementation of the National Rural Development Program; full and unconditional implementation of Government programs on EU integration; adaptation to the EU Common Agricultural Policy standards.

A detailed analysis of the hybrid lattice-reduction and meet-in-the-middle attack

2019 ◽  
Vol 13 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Thomas Wunderer
Keyword(s):  
Detailed Analysis ◽  
Runtime Analysis ◽  
Lattice Reduction ◽  
Signature Schemes ◽  
The Past ◽  
Encryption Schemes ◽  
Simplifying Assumptions ◽  
Security Levels

Abstract Over the past decade, the hybrid lattice-reduction and meet-in-the middle attack (called hybrid attack) has been used to evaluate the security of many lattice-based cryptographic schemes such as NTRU, NTRU Prime, BLISS and more. However, unfortunately, none of the previous analyses of the hybrid attack is entirely satisfactory: They are based on simplifying assumptions that may distort the security estimates. Such simplifying assumptions include setting probabilities equal to 1, which, for the parameter sets we analyze in this work, are in fact as small as 2^{-80} . Many of these assumptions lead to underestimating the scheme’s security. However, some lead to security overestimates, and without further analysis, it is not clear which is the case. Therefore, the current security estimates against the hybrid attack are not reliable, and the actual security levels of many lattice-based schemes are unclear. In this work, we present an improved runtime analysis of the hybrid attack that is based on more reasonable assumptions. In addition, we reevaluate the security against the hybrid attack for the NTRU, NTRU Prime and R-BinLWEEnc encryption schemes as well as for the BLISS and GLP signature schemes. Our results show that there exist both security over- and underestimates in the literature.

scholarly journals Rejection Sampling Revisit: How to Choose Parameters in Lattice-Based Signature

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhongxiang Zheng ◽  
Anyu Wang ◽  
Lingyue Qin
Keyword(s):  
Uniform Distribution ◽  
Sampling Theorem ◽  
New Method ◽  
Security Level ◽  
Rejection Sampling ◽  
Forgery Attack ◽  
Rejection Probability ◽  
Standardization Process ◽  
Security Levels ◽  
Security Bound

Rejection sampling technology is a core tool in the design of lattice-based signatures with ‘Fiat–Shamir with Aborts’ structure, and it is related to signing efficiency and signature, size as well as security. In the rejection sampling theorem proposed by Lyubashevsky, the masking vector of rejection sampling is chosen from discrete Gaussian distribution. However, in practical designs, the masking vector is more likely to be chosen from bounded uniform distribution due to better efficiency and simpler implementation. Besides, as one of the third-round candidate signatures in the NIST postquantum cryptography standardization process, the 3rd round version of CRYSTALS-Dilithium has proposed a new method to decrease the rejection probability in order to achieve better efficiency and smaller signature size by decreasing the number of nonzero coefficients of the challenge polynomial according to the security levels. However, it is seen that small entropies in this new method may lead to higher risk of forgery attack compared with former schemes proposed in its 2nd version. Thus, in this paper, we first analyze the complexity of forgery attack for small entropies and then introduce a new method to decrease the rejection probability without loss of security including the security against forgery attack. This method is achieved by introducing a new rejection sampling theorem with tighter bound by utilizing Rényi divergence where masking vector follows uniform distribution. By observing large gaps between the security claim and actual security bound in CRYSTALS-Dilithium, we propose two series of adapted parameters for CRYSTALS-Dilithium. The first set can improve the efficiency of the signing process in CRYSTALS-Dilithium by factors of 61.7 %  and  41.7 % , according to the security levels, and ensure the security against known attacks, including forgery attack. And, the second set can reduce the signature size by a factor of 14.09 % with small improvements in efficiency at the same security level.

scholarly journals Efficient Secret Image Sharing Scheme with Authentication and Cheating Prevention

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Lina Zhang ◽  
Xuan Dang ◽  
Li Feng ◽  
Junhan Yang
Keyword(s):  
Distributed Storage ◽  
Limited Resources ◽  
Secret Image Sharing ◽  
Authentication Codes ◽  
Authentication Code ◽  
Secret Image ◽  
Image Sharing ◽  
Sharing Scheme ◽  
Hash Algorithm ◽  
Security Levels

Due to the widespread adoption and popularity of digital images in distributed storage, Secret Image Sharing (SIS) has attracted much attention. However, preventing the cheating of shares is an important problem that needs to be solved in the traditional SIS scheme. An adversary without image shares may participate in the restoration phase as a share owner. In this phase, the adversary can obtain real shares or prevent recovering real images by submitting fake shadows. Our schemes are based on the original Thien-Lin’s scheme. In the scheme I, we use some XOR operations to get two authentication codes through all secret pixel values to achieve a lightweight and fast-calculated authentication scheme for cheating prevention. This scheme is suitable for small devices with limited resources. In scheme II, we use a hash algorithm to generate the authentication code. This scheme is suitable for environments with larger storage space and higher security levels. Since all pixel values are involved in the authentication in our proposed schemes, it can prevent fake shadow images from cheating. Meanwhile, the shadow size is almost the same as the original Thien-Lin’s scheme. Experimental results and theoretical analysis show that the proposed schemes are feasible and effective.

scholarly journals The SQALE of CSIDH: sublinear Vélu quantum-resistant isogeny action with low exponents

2021 ◽  
Author(s):  
Jorge Chávez-Saab ◽  
Jesús-Javier Chi-Domínguez ◽  
Samuel Jaques ◽  
Francisco Rodríguez-Henríquez
Keyword(s):  
Group Action ◽  
Key Exchange ◽  
Commutative Group ◽  
Constant Time ◽  
Square Root ◽  
Resource Constrained ◽  
Key Exchange Protocol ◽  
Security Levels ◽  
Commutative Group Action

AbstractRecent independent analyses by Bonnetain–Schrottenloher and Peikert in Eurocrypt 2020 significantly reduced the estimated quantum security of the isogeny-based commutative group action key-exchange protocol CSIDH. This paper refines the estimates of a resource-constrained quantum collimation sieve attack to give a precise quantum security to CSIDH. Furthermore, we optimize large CSIDH parameters for performance while still achieving the NIST security levels 1, 2, and 3. Finally, we provide a C-code constant-time implementation of those CSIDH large instantiations using the square-root-complexity Vélu’s formulas recently proposed by Bernstein, De Feo, Leroux and Smith.

scholarly journals Enhanced Merged Security Levels of BSPS in WLAN

2014 ◽  
Vol 88 (7) ◽  
pp. 26-34
Author(s):  
Avala Ramesh ◽  
S. Pallam Setty
Keyword(s):  
Security Levels
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