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Dynamic Time and Location Information in Ciphertext-Policy Attribute-Based Encryption with Multi-Authorization

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Intelligent Automation & Soft Computing 2023年第3期35卷 3801-3813页

作者： P.Prathap Nayudu Krovi raja sekhar Department of Computer Science and Engineering Koneru Lakshmaiah Education FoundationVaddeswaramAP522502India

Due to the mobility of users in an organization,inclusion of dynamic attributes such as time and location becomes the major challenge in Ciphertext-Policy Attribute-Based Encryption(CP-ABE).By considering this challenge;we focus to present dynamic time and location information in CP-ABE with ***ﬁrst,along with the set of attributes of the users,their corre-sponding location is also *** is used to encode the latitude and longitude of the user’s ***,decrypt time period and access time period of users are deﬁned using the new time tree(NTT)*** NTT sets the encrypted duration of the encrypted data and the valid access time of the private key on the data user’s private ***,single authorization of attribute authority(AA)is extended as multi authorization for enhancing the effectiveness of key *** results depict that the proposed CP-ABE achieves better encryption time,decryption time,security level and memory ***,encryption time and decryption time of the proposed CP-ABE are reduced to 19%and 16%than that of existing CP-ABE scheme.

关键词： CP-ABE geohash new time tree(NTT) multi authorization dynamic attribute

Secured Access Policy in Ciphertext-Policy Attribute-Based Encryption for Cloud Environment

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Computer Systems Science & Engineering 2023年第7期46卷 1079-1092页

作者： P.Prathap Nayudu Krovi raja sekhar Department of Computer Science and Engineering Koneru Lakshmaiah Education Foundation VaddeswaramAPIndia

The cloud allows clients to store and share *** on the user’s needs,it is imperative to design an effective access control plan to share the information only with approved *** user loses control of their data when the data is outsourced to the ***,access control mechanisms will become a significant challenging *** Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is an essential solution in which the user can control data ***-ABE encrypts the data under a limited access policy after the user sets some access *** user can decrypt the data if they satisfy the limited access *** CP-ABE is an effective access control program,the privacy of the policy might be compromised by the ***,the attackers can gather important information from plain text *** address this issue,the SHA-512 algorithm is presented to create a hash code for the user’s attributes in this *** on the created hash codes,an access policy will be *** leads to protecting the access policy against *** effectiveness of the proposed scheme is assessed based on decryption time,private key generation time,ciphertext generation time,and data verification time.

关键词： Cloud computing access policy CP-ABE hash code SHA-512 attribute ciphertext encryption decryption

A theoretical study on the elastic deformation of cellular phase and creation of necrosis due to the convection reaction process inside a spherical tumor

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International Journal of Biomathematics 2016年第6期9卷 273-306页

作者： Bibaswan Dey G. P. raja sekhar Department of MathematicsIndian Institute of Technology Kharagpur Kharagpur 721302 West Bengal India

Several biological processes, such as convective nutrient transport and convective drug delivery in biological tissues involves the transvascular and interstitial movement of biofluids. This work addresses transvascular and interstitial transport of nutrient inside a spherical tumor. Most of the biological tissues behave like deformable porous materiM and show mechanical behavior towards the fluid motion, due to the fact, that the forces like the drag, which is associated with fluid flow may compress the tissue material. On the macroscopic level, transport of solutes like nutrients, drug molecules, etc. within the tumor interstitial space is modeled. The hydrodynamic problem is treated with biphasic mixture theory under steady state and spherically symmetry situation. The transvascular transport of nutrient is modeled with the modified Sterling＇s equation. The present model describes the overall nutrient distribution and predicts various criteria for the necrosis formation inside the tumor. Present study justifies that the parameters, which controls the nutrient supply to the tumor interstitial space through the blood vessel network inside the tumor, competes with reversible nutrient consumption kinetics of the tumor cells. This study also finds the role of some of those parameters on the deformation of cellular phase of the tumor as a consequence of interstitial fluid flow.

关键词： Tumor vasculature isolated tumor biphasic mixture theory effectivenessfactor necrotic core.

Volumetric, Ultrasonic and Transport Properties of Binary Liquid Mixtures Containing Dimethyl Formamide at 303.15 K

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Chinese Journal of Chemistry 2007年第1期25卷 32-43页

作者： SYAMALA, Vardhana raja sekhar, Damaramadugu SIVA KUMAR, Kasibhatta VENKATESWARLU, Ponneri Thermochemical Laboratories Department of Chemistry Sri Venkateswara University Tirupati 517 502 India Department of Chemistry SVArts College Tirupati 517 502 India

Excess volumes （v^E）, ultrasonic velocities （u）, isentropic compressibility （△Ks） and viscosities （η） for the binary mixtures of dimethyl formamide （DMF） with 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,2,4-trichlorobenzene, o-chlorotoluene, m-chlorotoluene, p-chlorotoluene, o-nitrotoluene and m-nitrotoluene at 303.15 K were studied. Excess volume data exhibit an inversion in sign for the mixtures of dimethyl formamide with 1,2- and 1,3-dichlorobenzenes and the property is completely positive over the entire composition range for the mixtures of dimethyl formamide with 1,2,4-trichlorobenzene, o-nitrotoluene and m-nitrotoluene. On the other hand, the quantity is negative for the mixtures of dimethyl formamide with chlorotoluenes. Isentropic compressibility （Ks） has been computed for the same systems from precise sound velocity and density data. Further, deviation of isentropic com- pressibility （△Ks） from ideal behavior was also calculated. AKs values are negative over the entire volume fraction range in all the binary mixtures. The experimental sound velocity data were analysed in terms of Free Length Theory （FLT） and Collision Factor Theory （CFT）. The viscosity data were analysed on the basis of corresponding state approach. The measured data were discussed on the basis of intermolecular interactions between unlike molecules.

关键词： excess volume, dimethyl formamide, interferometer, sound velocity, viscosity molecular interaction

Medicago truncatula resources to study legume biology and symbiotic nitrogen fixation

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Fundamental Research 2023年第2期3卷 219-224页

作者： raja sekhar Nandety Jiangqi Wen Kirankumar S.Mysore Institute for Agricultural Biosciences Oklahoma State University3210 Sam Noble ParkwayArdmoreOK 73401United States USDA-ARS Cereal Crops Research UnitEdward T.Schafer Agricultural Research CenterFargoND 58102United States Department of Biochemistry and Molecular Biology Oklahoma State UniversityStillwaterOK 74078United States

Medicago truncatula is a chosen model for legumes towards deciphering fundamental legume biology,especially symbiotic nitrogen *** genomic resources for *** include a completed whole genome sequence information for R108 and Jemalong A17 accessions along with the sparse draft genome sequences for other 226 *** *** genomic resources are complemented by the availability of mutant resources such as retrotransposon(Tnt1)insertion mutants in R108 and fast neutron bombardment(FNB)mutants in *** addition,several *** databases such as small secreted peptides(SSPs)database,transporter protein database,gene expression atlas,proteomic atlas,and metabolite atlas are available to the research *** review describes these resources and provide information regarding how to access these resources.

关键词： Medicago truncatula Model legume Medicago resources Tnt1 Mutagenesis Medicago gene atlas

Effects of electron-and hole-current hysteresis on trap characterization in organo-inorganic halide perovskite

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Journal of Energy Chemistry 2023年第1期76卷 414-420,I0010页

作者： Fan Wu Sally Mabrouk Miaomiao Han Yanhua Tong Tiansheng Zhang Yuchen Zhang raja sekhar Bobba Quinn Qiao School of Science and Huzhou Key Lab of Materials for Energy Conversion and Storage Huzhou UniversityHuzhou 313000ZhejiangChina Mechanical and Aerospace Engineering Syracuse UniversitySyracuseNY13244United States

Charge trap density and carrier mobility of perovskite materials are the critical properties of perovskite solar *** space charge limited current(SCLC)method,which measures a dark current–voltage(I-V)curve of a single-carrier device has found extensive use for studying the trap density and charge carrier mobility in perovskite ***,it was found that the electron-and hole-current in organo-lead perovskite-based single-carrier device undergoes significant hysteresis under forward and reverse scanning due to the mobile *** addition,it was also observed that measuring history has a detrimental effect on hysteresis resulting in possible overestimation or underestimation of the extracted electrical values from the SCLC *** the forward/reverse scanning process,the mobile ionic defects enhance/shield the charge in the traps due to ionic charging/discharging,thereby increasing/reducing the interface barrier and net charge in the I-V scanning,which in turn affects the determination of transport properties of the *** results raise quite a few doubts over the direct application of classical SCLC measurements for the accurate characterization of intrinsic transport properties of the mixed ionicelectronic perovskite.

关键词： Organo-lead perovskite Ionic defects Space-charge-limited-current Trap density Mobility

Experimental Evaluation of Juniper Network's Netscreen-5GT Security Device against Layer4 Flood Attacks

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Journal of Information Security 2011年第1期2卷 50-58页

作者： Sanjeev Kumar raja sekhar Reddy Gade 不详

Cyber attacks are continuing to hamper working of Internet services despite increased use of network secu-rity systems such as firewalls and Intrusion protection systems (IPS). Recent Distributed Denial of Service (DDoS) attacks on Dec 8th, 2010 by Wikileak supporters on Visa and Master Card websites made headlines on prime news channels all over the world. Another famous DDoS attacks on Independence Day weekend, on July 4th, 2009 were launched to debilitate the US and South Korean governments’ websites. These attacks raised questions about the capabilities of the security systems that were used in the network to counteract such attacks. Firewall and IPS security systems are commonly used today as a front line defense mechanism to defend against DDoS attacks. In many deployments, performances of these security devices are seldom evaluated for their effectiveness. Different security devices perform differently in stopping DDoS attacks. In this paper, we intend to drive the point that it is important to evaluate the capability of Firewall or IPS secu-rity devices before they are deployed to protect a network or a server against DDoS attacks. In this paper, we evaluate the effectiveness of a security device called Netscreen 5GT (or NS-5GT) from Juniper Networks under Layer-4 flood attacks at different attack loads. This security device NS-5GT comes with a feature called TCP-SYN proxy protection to protect against TCP-SYN based DDoS attacks, and UDP protection feature to protect against UDP flood attacks. By looking at these security features from the equipments data sheet, one might assume the device to protect the network against such DDoS attacks. In this paper, we con-ducted real experiments to measure the performance of this security device NS-5GT under the TCP SYN and UDP flood attacks and test the performance of these protection features. It was found that the Juniper’s NS-5GT mitigated the effect of DDoS traffic to some extent especially when the attack of lower

关键词： Distributed Denial of Service (DDoS) TCP-SYN Flood Attack TCP-SYN Proxy Protection Firewall Security UDP Flood Attack

Experimental Evaluation of Cisco ASA-5510 Intrusion Prevention System against Denial of Service Attacks

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Journal of Information Security 2012年第2期3卷 122-137页

作者： Sanjeev Kumar raja sekhar Reddy Gade Networking Research Lab Department of Electrical/Computer Engineering The University of Texas-Pan American Edinburg USA

Cyber attacks are continuing to hamper working of Internet services despite increase in the use of network security systems such as, firewalls and Intrusion protection systems (IPS). Recent Denial of Service (DoS) attack on Independence Day weekend, on July 4th, 2009 launched to debilitate the US and South Korean governments’ websites is indicative of the fact that the security systems may not have been adequately deployed to counteract such attacks. IPS is a vital security device which is commonly used as a front line defense mechanism to defend against such DoS attacks. Before deploying a firewall or an IPS device for network protection, in many deployments, the performance of firewalls is seldom evaluated for their effectiveness. Many times, these IPS’s can become bottleneck to the network performance and they may not be effective in stopping DoS attacks. In this paper, we intend to drive the point that deploying IPS may not always be effective in stopping harmful effects of DoS attacks. It is important to evaluate the capability of IPS before they are deployed to protect a network or a server against DoS attacks. In this paper, we evaluate performance of a commercial grade IPS Cisco ASA-5510 IPS to measure its effectiveness in stopping a DoS attacks namely TCP-SYN, UDP Flood, Ping Flood and ICMP Land Attacks. This IPS comes with features to counteract and provide security against these attacks. Performance of the IPS is measured under these attacks protection and compared with its performance when these protection features were not available (i.e. disabled). It was found that the IPS was unable to provide satisfactory protection despite the availability of the protection features against these flooding attacks. It is important for the network managers to measure the actual capabilities of an IPS system before its deployment to protect critical information infrastructure.

关键词： Denial of Service (DoS) SYN Flood Attack Proxy Protection Firewall Security Availability

Evaluation of Microsoft Windows Servers 2008 &2003 against Cyber Attacks

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Journal of Information Security 2015年第2期6卷 155-160页

作者： Sanjeev Kumar Senior Member raja sekhar Reddy Gade Department of Electrical Engineering The University of Texas-Pan American Edinburg TX USA

Distributed Denial of Service (DDoS) is known to compromise availability of Information Systems today. Widely deployed Microsoft’s Windows 2003 & 2008 servers provide some built-in protection against common Distributed Denial of Service (DDoS) attacks, such as TCP/SYN attack. In this paper, we evaluate the performance of built-in protection capabilities of Windows servers 2003 & 2008 against a special case of TCP/SYN based DDoS attack. Based on our measurements, it was found that the built-in security features which are available by default on Microsoft’s Windows servers were not sufficient in defending against the TCP/SYN attacks even at low intensity attack traffic. Under TCP/SYN attack traffic, the Microsoft 2003 server was found to crash due to processor resource exhaustion, whereas the 2008 server was found to crash due to its memory resource depletion even at low intensity attack traffic.

关键词： Cyber Warfare Distributed Denial of Service Attacks TCP/SYN Flood Processor Resource Exhaustion Memory Resource Exhaustion