scholarly journals Research on SKINNY Optimal Differential Trail Search

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Shaoqiang Liu ◽  
Chaiyang Peng ◽  
Chunjiang Li

SKINNY is a tweakable lightweight block cipher algorithm. In order to test its security, this paper performs optimal differential trail search analysis on all SKINNY-64 versions under single-key setting based on the MILP (Mixed Integer Linear Programming) algorithm. Firstly, SKINNY round function is abstracted equivalently by precise constraints, and the objective function is set as the minimum number of active S-box number to optimize SKINNY-64 MILP model. Experiments show the differential trail searched by this method is not necessarily optimal. In order to directly search for the optimal differential trail, the S-box differential probability coding information is added to the optimized SKINNY-64 MILP model, the S-box differential characteristic is reconstructed, and the objective function is set to the minimum value of the probability coding information, which improves the SKINNY-64 MILP model. The results of experimental show that the improved MILP model can directly search for the optimal differential trail, and the complexity is slightly increased, but the search efficiency is significantly improved. Under single-key setting, this method has obvious advantage in searching the optimal differential trails of SKINNY-64 with low round number.

2021 ◽  
Vol 13 (20) ◽  
pp. 11373
Author(s):  
Shouxu Song ◽  
Yongting Tian ◽  
Dan Zhou

In recent years, mobile payments have gradually replaced cash payments, resulting in a gradual decline in the number of automatic teller machines (ATMs) demanded by banks. Through investigation and analysis, we determine four means to deal with decommissioned ATMs, and construct thereafter an ATM reverse logistics (RL_ATMs) network model, which includes suppliers, producers, warehouses, operators, maintenance centers, collection and inspection centers, disposal centers, remanufacturing centers, and recycling centers. This model is further expressed as a mixed integer linear programming (MILP) model. Given that an ATM recycling network has planned and batched characteristics, a percentage diversion method is proposed to transform a real multi-cycle problem to a single-cycle problem. The RL_ATMs network constructed in this study presents the two forms of ATMs, functional modules and the entire machine. We used the actual situations of the related companies and enterprises in Anhui Province and its surrounding areas, as well as major banks’ ATMs, as bases in using the LINGO software to solve the proposed MILP model with the objective function of minimizing costs and environmental emissions, and obtain the relevant companies’ launch operations. Lastly, we analyzed the relationship between coefficients in the percentage diversion method and calculation results, cost, and carbon emissions. Accordingly, we find that the number of remanufacturing and maintenance centers has no evident impact on the objective function, transportation costs account for a large proportion of the total cost, and emissions tax is small.


2021 ◽  
Author(s):  
Mohammad Ehsan Zerafati ◽  
Ali Bozorgi-Amiri ◽  
Amir-Mohammad Golmohammadi ◽  
Fariborz Jolai

Abstract Recently, due to the efficiency of cultivating microalgae, researchers and investors have paid considerable attention to the production of different biofuel products that are environmentally friendly. In this study, a two-stage deterministic model is proposed to design a microalgae-based biofuels and co-products supply chain network (MBCSCN). In the first stage, the appropriate locations for the cultivation of microalgae are identified through the analytical hierarchy process (AHP). In the second stage, a deterministic mathematical mixed integer linear programing (MILP) model is developed for a period of five years based on the criteria of economic and environmental impacts. The economic objective function maximizes the overall profit, while the environmental impacts objective function seeks to minimize the consumed fossil fuel throughout the supply chain. Then, a multi-objective MILP optimization problem is solved using the ε-constraint method. The proposed model is evaluated through a case study in Iran. It has helped to identify appropriate locations for the cultivation of microalgae and to specify the required quantity of feedstock, the species of microalgae, the required technology, and the transportation modes in each step of the supply chain.


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