scholarly journals HILL CIPHER ON SHAMIR’S THREE PASS PROTOCOL

2017 ◽  
Author(s):  
hasdiana

This preprint has been presented in the 3rd International Conference on Multidisciplinary Research, Medan, october 16 – 18, 2014---In this study the authors use the scheme of Shamir's Three Pass Protocol for Hill Cipher operation. Scheme of Shamir's Three Pass Protocol is an attractive scheme that allows senders and receivers to communicate without the key exchange. Hill Cipher is chosen because of the key-shaped matrix, which is expected to complicate the various techniques of cryptanalyst. The results of this study indicate that the weakness of the scheme of Shamir's Three Pass Protocol for XOR operation is not fully valid if it is used for Hill Cipher operations. Cryptanalyst can utilize only the third ciphertext that invertible. Matrix transpose techniques in the ciphertext aims to difficulties in solving this algorithm. The original ciphertext generated in each process is different from the transmitted ciphertext. The level of difficulty increases due to the use of larger key matrix. The amount of time required for the execution of the program depends on the length of the plaintext and the value of the matrix element. Plaintext has the same length produce different execution time depending on the value of the key elements of the matrix used.

Games ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 62
Author(s):  
Ralph S. Redden ◽  
Greg A. Gagliardi ◽  
Chad C. Williams ◽  
Cameron D. Hassall ◽  
Olave E. Krigolson

When we play competitive games, the opponents that we face act as predictors of the outcome of the game. For instance, if you are an average chess player and you face a Grandmaster, you anticipate a loss. Framed in a reinforcement learning perspective, our opponents can be thought of as predictors of rewards and punishments. The present study investigates whether facing an opponent would be processed as a reward or punishment depending on the level of difficulty the opponent poses. Participants played Rock, Paper, Scissors against three computer opponents while electroencephalographic (EEG) data was recorded. In a key manipulation, one opponent (HARD) was programmed to win most often, another (EASY) was made to lose most often, and the third (AVERAGE) had equiprobable outcomes of wins, losses, and ties. Through practice, participants learned to anticipate the relative challenge of a game based on the opponent they were facing that round. An analysis of our EEG data revealed that winning outcomes elicited a reward positivity relative to losing outcomes. Interestingly, our analysis of the predictive cues (i.e., the opponents’ faces) demonstrated that attentional engagement (P3a) was contextually sensitive to anticipated game difficulty. As such, our results for the predictive cue are contrary to what one might expect for a reinforcement model associated with predicted reward, but rather demonstrate that the neural response to the predictive cue was encoding the level of engagement with the opponent as opposed to value relative to the anticipated outcome.


Parasitology ◽  
1946 ◽  
Vol 37 (3-4) ◽  
pp. 192-201 ◽  
Author(s):  
J. F. A. Sprent

A description is given of the processes of copulation, formation of the egg and spermatozoon, cleavage, embryogeny and hatching in B. phlebotomum. These processes were found to be essentially similar to those in other strongyle nematodes.The anatomy of the first three larval stages is described and the observations of Conradi & Barnette (1908) and Schwartz (1924) were largely confirmed.Penetration of the skin of calves by the infective larva was observed histologically. The larvae were found to have reached the dermis within 30 min. and to have penetrated the cutaneous blood vessels within 60 min. of application to the skin. The larvae were found in the lung where the third ecdysis was in progress 10 days after penetration of the skin. A description is given of the growth of the third-stage larva in the lung, the changes which take place during the third ecdysis, and the anatomy of the fourth-stage larva.The fourth-stage larvae exsheath in the lungs and travel to the intestine. After a period of growth in which sexual differentiation takes place, the fourth ecdysis occurs and the adult parasite emerges. The time required for the attainment of maturity was found to be somewhere between 30 and 56 days after penetration of the skin.This paper was written at the Ministry of Agriculture and Fisheries Veterinary Laboratories, Wey-bridge, and the writer would like to express his gratitude to the Director, Prof. T. Dalling, also to Dr W. R. Wooldridge, chairman of the Council of the Veterinary Educational Trust for their help and encouragement. The writer's thanks are also due to Dr H. A. Baylis, Prof. R. T. Leiper and Dr E. L. Taylor for their advice and help on technical points, and to Mr R. A. O. Shonekan, African laboratory assistant, for his able co-operation.


2011 ◽  
Vol 02 ◽  
pp. 183-187
Author(s):  
◽  
Y. CHEN

Several measurements on light hadron spectroscopy have been achieved with Beijing Spectrometry III (BESIII). BESII results such as a near threshold enhancement on the [Formula: see text] invariants mass spectrum namely X(1860) and a resonance X(1835) have been confirmed with 225 million J/ψ data accumulated from June 12, 2009 to July 28, 2009. Along with some other preliminary BESIII results including observations of X(1870), X(2120) and X(2370); the first direct measurement of a0(980)/f0(980) mixing; and an improved measurement on the matrix element of decay η′ → ππη have been reported at the 4th international workshop on charm physics.


1995 ◽  
Vol 73 (S1) ◽  
pp. 453-458 ◽  
Author(s):  
Hiroshi Otani ◽  
Keisuke Kohmoto ◽  
Motoichiro Kodama

There are now nine or more Alternaria pathogens that produce host-specific toxins, and the structures of most of the toxins have been elucidated. Alternaria host-specific toxins are classified in three groups in terms of the primary site action. ACT-, AF-, and AK-toxins have in common an epoxy-decatrienoic acid structure and exert their primary effect on the plasma membrane of susceptible cells. A rapid increase in electrolyte loss from tissues and invaginations in the plasma membranes are common effects of these toxins. The second group is represented by ACR(L)-toxin, which induces changes in mitochondria, including swelling, vesiculation of cristae, decrease in the electron density of the matrix, increase in the rate of NADH oxidation, and inhibition of malate oxidation. The third group consists of AM-toxin, which appears to exert an early effect on both chloroplasts and plasma membranes. AM-toxin induces vesiculation of grana lamellae, inhibition of CO2 fixation, invagination of plasma membranes, and electrolyte loss. The roles of host-specific toxins in pathogenesis are discussed. Key words: Alternaria, host-specific toxin, plasma membrane, mitochondrion, chloroplast.


2012 ◽  
Vol 2012 (11) ◽  
Author(s):  
John M. Campbell ◽  
Walter T. Giele ◽  
Ciaran Williams

2006 ◽  
Vol 4 (4) ◽  
pp. 479-486 ◽  
Author(s):  
Naoko Nakagawa ◽  
Hana Oe ◽  
Masahiro Otaki ◽  
Katsuyoshi Ishizaki

The Sustainable Sanitation System is a new wastewater treatment system that incorporates a non-flushing toilet (Bio-toilet) that converts excreta into a reusable resource (as fertilizer or humus for organic agriculture) and reduces the pollution load to environments of the rivers, the lakes, and the sea. However, the risk of exposure to pathogens should be considered, because excrement is stored in the Bio-toilet. The aim of the present work is to analyze the health risk of dealing with the matrix (excreta and urine mixed with sawdust) of the Bio-toilet. Therefore, the fate of pathogenic viruses was investigated using coliphages as a virus index, and the modeling of the die-off rate in matrix was introduced. Then the microbial risk assessment was applied to a Bio-toilet that was actually used in a residential house; the infection risks of rotavirus and enterovirus as reference pathogens were calculated. According to the lab-scale experiment using coliphages for investing the die-off rate of viruses in the Bio-toilet, Qβ had a higher die-off, which was greatly influenced by the water content and temperature. On the other hand, T4 showed a lower rate and was independent of water content. Therefore, these two phages' data were used as critical examples, such as viruses having high or low possibilities of remaining in the Bio-toilet during the risk assessment analysis. As the result of the risk assessment, the storage time required for an acceptable infectious risk level has wide variations in both rotavirus and enterovirus cases depending on the phage that was used. These were 0–260 days' and 0–160 days' difference, respectively.


2021 ◽  
Vol 25 (2) ◽  
pp. 98-109
Author(s):  
P. A. Otopkova ◽  
◽  
A. M. Potapov ◽  
A. I. Suchkov ◽  
A. D. Bulanov ◽  
...  

In order to study the isotopic effects in semiconductor materials, single crystals of high chemical and isotopic purity are required. The reliability of the obtained data on the magnitude and the direction of isotopic shifts depends on the accuracy of determining the concentration of all stable isotopes. In the isotopic analysis of enriched “silicon-28” with a high degree of enrichment (> 99.99%), it is necessary to determine the impurities of 29Si and 30Si isotopes at the level of 10-3 ¸ 10-5 at. %. At this concentration level, these isotopes can be considered as impurities. It is difficult to achieve high measurement accuracy with simultaneous registration of the main and “impurity” isotopes in such a wide range of concentrations. The registration of analytical signals of silicon isotopes must be carried out in the solutions with different matrix concentrations. The use of the solutions with the high concentration of the matrix element requires the introduction of corrections for matrix noise and the drift of the instrument sensitivity during the measurement. It is possible to reduce the influence of the irreversible non-spectral interference and sensitivity drift by using the method of internal standardization. The inconsistency of the literature data on the selection criteria for the internal standard required studying the behavior of the signals of the “candidates for the internal standard” for the ELEMENT 2 single-collector high-resolution inductively coupled plasma mass spectrometer on the matrix element concentration and the nature of the solvent, as well as on the solution nebulizing time. Accounting for the irreversible non-spectral matrix noise and instrumental drift in isotopic analysis of enriched “silicon-28” and initial 28SiF4 by inductively coupled plasma mass spectrometry had allowed us to reduce by 3-5 times the random component and by more than an order of magnitude the systematic component of the measurement error in comparison with the external standard method. This made it possible to carry out, with sufficient accuracy, the operational control of the isotopic composition of enriched “silicon-28”, both in the form of silicon tetrafluoride and polycrystalline silicon obtained from it, using a single serial device in the range of isotopic concentrations 0.0001–99.999%.


2021 ◽  
Author(s):  
Michael Prendergast

This paper describes a new method for performing secure encryption of blocks of streaming data. This algorithm is an extension of the RSA encryption algorithm. Instead of using a public key (e,n) where n is the product of two large primes and e is relatively prime to the Euler Totient function, φ(n), one uses a public key (n,m,E), where m is the rank of the matrix E and E is an invertible matrix in GL(m,φ(n)). When m is 1, this last condition is equivalent to saying that E is relatively prime to φ(n), which is a requirement for standard RSA encryption. Rather than a secret private key (d,φ(n)) where d is the inverse of e (mod φ(n)), the private key is (D,φ(n)), where D is the inverse of E (mod (φ(n)). The key to making this generalization work is a matrix generalization of the scalar exponentiation operator that maps the set of m-dimensional vectors with integer coefficients modulo n, onto itself.


Sign in / Sign up

Export Citation Format

Share Document