An asymmetric cryptosystem based on the random weighted singular value decomposition and fractional Hartley domain

2019 ◽  
Vol 79 (47-48) ◽  
pp. 34717-34735 ◽  
Author(s):  
R. Girija ◽  
Hukum Singh
Author(s):  
Shivani Yadav ◽  
Hukum Singh

Background: An asymmetric cryptanalysis is suggested in Affine and Fresnel transform using hybrid Fresnel Phase Mask (HFM), hybrid Mask (HM) and singular value decomposition (SVD) to deliver additional security to the scheme. The usage of Affine transform (AT) provides randomness in the input plane which benefits in enlarging the key space and SVD gives the non-linearity in the process. Objective: In the FrT domain, usage of hybrid masks and AT in an asymmetric cryptosystem with SVD is to make encoded procedure difficult. Method: On the plain image we firstly apply affine transform and then convoluted it with HFM, in FrT domain with propagation distance Z1 and the obtained part is convoluted with HM in FrT with propagation distance Z2 and then lastly on the encoded image SVD is applied. Results: Validity of the suggested scheme have been confirmed by using MATLAB R2018a (9.4.0.813654). The capability of the recommended scheme has been tested by statistical simulations such as histogram, entropy and correlation coefficient. Noise attack analysis has also done so that the system becomes robust against attacks. Conclusion: Asymmetric cryptosystem is recommended using pixel scrambling technique i.e. affine transform which shuffles the pixels hence helps for security of the system. Usage of SVD in the algorithm is to make the system robust. Performance and strength analysis are carried out for scrutiny of the forte and feasibility of the algorithm.


2021 ◽  
Vol 11 (4) ◽  
pp. 1928
Author(s):  
Khurram Naeem ◽  
Bok Hyeon Kim ◽  
Dong-Jin Yoon ◽  
Il-Bum Kwon

We propose a weighted singular value decomposition (WSVD) to reduce the random noise in the Rayleigh backscattering signal of the phase-sensitive optical time domain reflectometry (Φ-OTDR) to enhance the detection performance of the distributed vibration sensing. A 2D image is formed by assembling the raw Rayleigh backscattering traces into a matrix form, and slowly varying fluctuation and random noise can be removed using the WSVD. Consequently, the location information and the frequency of vibration induced by the external vibration event can be extracted. A vibration event with 9 m spatial resolution is detected along a 2.4 km single mode fiber. The signal-to-noise ratio (SNR) of location information for the 102 Hz physical vibration and the 525 Hz acoustic vibration was found to be 10.7 and 12.2 dB, respectively. The SNR of the vibration events demonstrate an increase of 6–7 dB compared to the conventional method, showing the excellent denoising capability of this new approach.


Sign in / Sign up

Export Citation Format

Share Document