Abstract: We report a computational study of the spreading
dynamics of a viral infection in a complex (scale-free) network. The
final epidemic size distribution (FESD) was found to be unimodal or
bimodal depending on the value of the basic reproductive
number R0 . The FESDs occurred on time-scales long enough for
intermediate-time epidemic size distributions (IESDs) to be important
for control measures. The usefulness of R0 for deciding on the
timeliness and intensity of control measures was found to be limited
by the multimodal nature of the IESDs and by its inability to inform
on the speed at which the infection spreads through the population. A
reduction of the transmission probability at the hubs of the scale-free
network decreased the occurrence of the larger-sized epidemic events
of the multimodal distributions. For effective epidemic control, an
early reduction in transmission at the index cell and its neighbors was
essential.
Abstract: We propose an enhanced key management scheme
based on Key Infection, which is lightweight scheme for tiny sensors.
The basic scheme, Key Infection, is perfectly secure against node
capture and eavesdropping if initial communications after node
deployment is secure. If, however, an attacker can eavesdrop on
the initial communications, they can take the session key. We use
common neighbors for each node to generate the session key. Each
node has own secret key and shares it with its neighbor nodes. Then
each node can establish the session key using common neighbors-
secret keys and a random number. Our scheme needs only a few
communications even if it uses neighbor nodes- information. Without
losing the lightness of basic scheme, it improves the resistance against
eavesdropping on the initial communications more than 30%.
Abstract: We propose a decoy-pulse protocol for frequency-coded implementation of B92 quantum key distribution protocol. A direct extension of decoy-pulse method to frequency-coding scheme results in security loss as an eavesdropper can distinguish between signal and decoy pulses by measuring the carrier photon number without affecting other statistics. We overcome this problem by optimizing the ratio of carrier photon number of decoy-to-signal pulse to be as close to unity as possible. In our method the switching between signal and decoy pulses is achieved by changing the amplitude of RF signal as opposed to modulating the intensity of optical signal thus reducing system cost. We find an improvement by a factor of 100 approximately in the key generation rate using decoy-state protocol. We also study the effect of source fluctuation on key rate. Our simulation results show a key generation rate of 1.5×10-4/pulse for link lengths up to 70km. Finally, we discuss the optimum value of average photon number of signal pulse for a given key rate while also optimizing the carrier ratio.
Abstract: Computer technology and the Internet have made a
breakthrough in the existence of data communication. This has
opened a whole new way of implementing steganography to ensure
secure data transfer. Steganography is the fine art of hiding the
information. Hiding the message in the carrier file enables the
deniability of the existence of any message at all. This paper designs
a stego machine to develop a steganographic application to hide data
containing text in a computer video file and to retrieve the hidden
information. This can be designed by embedding text file in a video
file in such away that the video does not loose its functionality using
Least Significant Bit (LSB) modification method. This method
applies imperceptible modifications. This proposed method strives
for high security to an eavesdropper-s inability to detect hidden
information.
Abstract: In this paper, a novel LVTSCR-based device for
electrostatic discharge (ESD) protection of integrated circuits (ICs) is
designed, fabricated and characterized. The proposed device is similar
to the conventional LVTSCR but it has an embedded PMOSFET in the
anode n-well to enhance the turn on speed, the clamping capability and
the robustness. This is possible because the embedded PMOSFET
provides the sub-path of ESD discharge current. The TLP, HBM and
MM testing are carried out to verify the ESD performance of the
proposed devices, which are fabricated in 0.35um
(Bipolar-CMOS-DMOS) BCDMOS process. The device has the
robustness of 70mA/um that is higher about 60mA/um than the
LVTSCR, approximately.
Abstract: RFID (Radio Frequency IDentification) system has
been widely used in our life, such as transport systems, passports,
automotive, animal tracking, human implants, library, and so on.
However, the RFID authentication protocols between RF (Radio
Frequency) tags and the RF readers have been bring about various
privacy problems that anonymity of the tags, tracking, eavesdropping,
and so on. Many researchers have proposed the solution of the
problems. However, they still have the problem, such as location
privacy, mutual authentication. In this paper, we show the problems of
the previous protocols, and then we propose a more secure and
efficient RFID authentication protocol.
Abstract: In the current research, we present an operation framework and protection mechanism to facilitate secure environment to protect mobile agents against tampering. The system depends on the presence of an authentication authority. The advantage of the proposed system is that security measures is an integral part of the design, thus common security retrofitting problems do not arise. This is due to the presence of AlGamal encryption mechanism to protect its confidential content and any collected data by the agent from the visited host . So that eavesdropping on information from the agent is no longer possible to reveal any confidential information. Also the inherent security constraints within the framework allow the system to operate as an intrusion detection system for any mobile agent environment. The mechanism is tested for most of the well known severe attacks against agents and networked systems. The scheme proved a promising performance that makes it very much recommended for the types of transactions that needs highly secure environments, e. g., business to business.
Abstract: Wireless sensor networks can be used to measure and monitor many challenging problems and typically involve in monitoring, tracking and controlling areas such as battlefield monitoring, object tracking, habitat monitoring and home sentry systems. However, wireless sensor networks pose unique security challenges including forgery of sensor data, eavesdropping, denial of service attacks, and the physical compromise of sensor nodes. Node in a sensor networks may be vanished due to power exhaustion or malicious attacks. To expand the life span of the sensor network, a new node deployment is needed. In military scenarios, intruder may directly organize malicious nodes or manipulate existing nodes to set up malicious new nodes through many kinds of attacks. To avoid malicious nodes from joining the sensor network, a security is required in the design of sensor network protocols. In this paper, we proposed a security framework to provide a complete security solution against the known attacks in wireless sensor networks. Our framework accomplishes node authentication for new nodes with recognition of a malicious node. When deployed as a framework, a high degree of security is reachable compared with the conventional sensor network security solutions. A proposed framework can protect against most of the notorious attacks in sensor networks, and attain better computation and communication performance. This is different from conventional authentication methods based on the node identity. It includes identity of nodes and the node security time stamp into the authentication procedure. Hence security protocols not only see the identity of each node but also distinguish between new nodes and old nodes.
Abstract: Privacy issues commonly discussed among
researchers, practitioners, and end-users in pervasive healthcare.
Pervasive healthcare systems are applications that can support
patient-s need anytime and anywhere. However, pervasive healthcare
raises privacy concerns since it can lead to situations where patients
may not be aware that their private information is being shared and
becomes vulnerable to threat. We have systematically analyzed the
privacy issues and present a summary in tabular form to show the
relationship among the issues. The six issues identified are medical
information misuse, prescription leakage, medical information
eavesdropping, social implications for the patient, patient difficulties
in managing privacy settings, and lack of support in designing
privacy-sensitive applications. We narrow down the issues and chose
to focus on the issue of 'lack of support in designing privacysensitive
applications' by proposing a privacy-sensitive architecture
specifically designed for pervasive healthcare monitoring systems.
Abstract: The purpose of this research is to develop a security model for voice eavesdropping protection over digital networks. The proposed model provides an encryption scheme and a personal secret key exchange between communicating parties, a so-called voice data transformation system, resulting in a real-privacy conversation. The operation of this system comprises two main steps as follows: The first one is the personal secret key exchange for using the keys in the data encryption process during conversation. The key owner could freely make his/her choice in key selection, so it is recommended that one should exchange a different key for a different conversational party, and record the key for each case into the memory provided in the client device. The next step is to set and record another personal option of encryption, either taking all frames or just partial frames, so-called the figure of 1:M. Using different personal secret keys and different sets of 1:M to different parties without the intervention of the service operator, would result in posing quite a big problem for any eavesdroppers who attempt to discover the key used during the conversation, especially in a short period of time. Thus, it is quite safe and effective to protect the case of voice eavesdropping. The results of the implementation indicate that the system can perform its function accurately as designed. In this regard, the proposed system is suitable for effective use in voice eavesdropping protection over digital networks, without any requirements to change presently existing network systems, mobile phone network and VoIP, for instance.
Abstract: The usage of internet is rapidly increasing and the usage of mobile agent technology in internet environment has a great demand. The security issue one of main obstacles that restrict the mobile agent technology to spread. This paper proposes Secure-Image Mechanism (SIM) as a new mechanism to protect mobile agents against malicious hosts. . SIM aims to protect mobile agent by using the symmetric encryption and hash function in cryptography science. This mechanism can prevent the eavesdropping and alteration attacks. It assists the mobile agents to continue their journey normally incase attacks occurred.
Abstract: Automatic tube current modulation (ATCM) systems are available for all CT manufacturers and are used for the majority of patients. Understanding how the systems work and their influence on patient dose and image quality is important for CT users, in order to gain the most effective use of the systems. In the present study, a new phantom was used for evaluating dose distribution and image quality under the ATCM operation for the Toshiba Aquilion 64 CT scanner using different ATCM options and a fixed mAs technique. A routine chest, abdomen and pelvis (CAP) protocol was selected for study and Gafchromic film was used to measure entrance surface dose (ESD), peripheral dose and central axis dose in the phantom. The results show the dose reductions achievable with various ATCM options, in relation with the target noise. The doses and image noise distribution were more uniform when the ATCM system was implemented compared with the fixed mAs technique. The lower limit set for the tube current will affect the modulations especially for the lower dose option. This limit prevented the tube current being reduced further and therefore the lower dose ATCM setting resembled a fixed mAs technique. Selection of a lower tube current limit is likely to reduce doses for smaller patients in scans of chest and neck regions.
Abstract: Modern Society is strongly dependent on a reliable
power supply. The availability of cheap and reliable supply of
electrical energy is an indicator of societal welfare. Uninterrupted
reliable operation of a modern power system depends to a great
extent on reliable and satisfactory performance of insulators under
different environmental conditions. This paper reports result of
natural pollution tests that have been done at sites around city of
Aligarh (India). Flashover voltage per insulation distance (FOVUID)
of porcelain disc insulator for different pH values, ESDD has been
recorded for proper correlation between electrical and chemical
parameters. The pH of the contaminants has been suggested to be an
effective pollution severity indicator and may be used as a diagnostic
parameter for proper maintenance of porcelain insulators.
Abstract: The paper presents a compressor anti-surge control
system, that results in maximizing compressor throughput with
pressure standard deviation reduction, increased safety margin
between design point and surge limit line and avoiding possible
machine surge. Alternative control strategies are presented.