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HoneyMesh: Preventing Distributed Denial of Service Attacks using Virtualized Honeypots  [PDF]
Hrishikesh Arun Deshpande
Computer Science , 2015, DOI: 10.17577/IJERTV4IS080325
Abstract: Today, internet and web services have become an inseparable part of our lives. Hence, ensuring continuous availability of service has become imperative to the success of any organization. But these services are often hampered by constant threats from myriad types of attacks. One such attack is called distributed denial of service attack that results in issues ranging from temporary slowdown of servers to complete non-availability of service. Honeypot, which is a sort of a trap, can be used to interact with potential attackers to deflect, detect or prevent such attacks and ensure continuous availability of service. This paper gives insights into the problems posed by distributed denial of service attacks, existing solutions that use honeypots and how a mesh of virtualized honeypots can be used to prevent distributed denial of service attacks.
Parsing Inside-Out  [PDF]
Joshua Goodman
Computer Science , 1998,
Abstract: The inside-outside probabilities are typically used for reestimating Probabilistic Context Free Grammars (PCFGs), just as the forward-backward probabilities are typically used for reestimating HMMs. I show several novel uses, including improving parser accuracy by matching parsing algorithms to evaluation criteria; speeding up DOP parsing by 500 times; and 30 times faster PCFG thresholding at a given accuracy level. I also give an elegant, state-of-the-art grammar formalism, which can be used to compute inside-outside probabilities; and a parser description formalism, which makes it easy to derive inside-outside formulas and many others.
Inside-Out Planet Formation  [PDF]
Sourav Chatterjee,Jonathan C. Tan
Physics , 2013, DOI: 10.1088/0004-637X/780/1/53
Abstract: The compact multi-transiting planet systems discovered by Kepler challenge planet formation theories. Formation in situ from disks with radial mass surface density, $\Sigma$, profiles similar to the minimum mass solar nebula (MMSN) but boosted in normalization by factors $\gtrsim 10$ has been suggested. We propose that a more natural way to create these planets in the inner disk is formation sequentially from the inside-out via creation of successive gravitationally unstable rings fed from a continuous stream of small (~cm--m size) "pebbles", drifting inwards via gas drag. Pebbles collect at the pressure maximum associated with the transition from a magneto-rotational instability (MRI)-inactive ("dead zone") region to an inner MRI-active zone. A pebble ring builds up until it either becomes gravitationally unstable to form an $\sim 1\ M_\oplus$ planet directly or induces gradual planet formation via core accretion. The planet may undergo Type I migration into the active region, allowing a new pebble ring and planet to form behind it. Alternatively if migration is inefficient, the planet may continue to accrete from the disk until it becomes massive enough to isolate itself from the accretion flow. A variety of densities may result depending on the relative importance of residual gas accretion as the planet approaches its isolation mass. The process can repeat with a new pebble ring gathering at the new pressure maximum associated with the retreating dead zone boundary. Our simple analytical model for this scenario of inside-out planet formation yields planetary masses, relative mass scalings with orbital radius, and minimum orbital separations consistent with those seen by Kepler. It provides an explanation of how massive planets can form with tightly-packed and well-aligned system architectures, starting from typical protoplanetary disk properties.
Inside-out Galaxy Formation  [PDF]
Jeremy Kepner
Physics , 1997, DOI: 10.1086/307419
Abstract: Current theories of galaxy formation have tended to focus on hierarchical structure formation, which is the most likely scenario for cosmological models with lots of power at small scales (e.g. standard cold dark matter). Models with little small scale power lead to scenarios closer to spherical collapse. Recently favored power spectra (e.g. CDM+Lambda) lie somewhere in between suggesting that both types of processes are important and may vary over time due to gaseous reheating. From this viewpoint this paper explores a very simple inside out scenario for galaxy formation. This scenario is a natural result of synthesizing earlier work on DM halos, spherical collapse, and gas redistribution via angular momentum. Although, this model is highly simplified and is not designed to accurately describe the detailed formation of any individual galaxy, it does (by design) predict the overall features of galaxies. In addition, old bulges and young disks are an almost unavoidable result of these very simple models. This scenario may provide a useful framework for both observers and theoreticians to think about galaxy formation.
Preventing Distributed Denial-of-Service Attacks on the IMS Emergency Services Support through Adaptive Firewall Pinholing  [PDF]
Andreea Ancuta Onofrei,Yacine Rebahi,Thomas Magedanz
International Journal of Next-Generation Networks , 2010,
Abstract: Emergency services are vital services that Next Generation Networks (NGNs) have toprovide. As the IP Multimedia Subsystem (IMS) is in the heart of NGNs, 3GPP has carriedthe burden of specifying a standardized IMS-based emergency services framework. Unfortunately,like any other IP-based standards, the IMS-based emergency service framework isprone to Distributed Denial of Service (DDoS) attacks. We propose in this work, a simplebut efficient solution that can prevent certain types of such attacks by creating firewall pinholesthat regular clients will surely be able to pass in contrast to the attackers clients. Oursolution was implemented, tested in an appropriate testbed, and its efficiency was proven.
Preventing Distributed Denial-of-Service Attacks on the IMS Emergency Services Support through Adaptive Firewall Pinholing  [PDF]
Andreea Ancuta Onofrei,Yacine Rebahi,Thomas Magedanz,Fokus Fraunhofer Institute,Germany
Computer Science , 2010, DOI: 10.5121/ijngn.2010.2101
Abstract: Emergency services are vital services that Next Generation Networks (NGNs) have to provide. As the IP Multimedia Subsystem (IMS) is in the heart of NGNs, 3GPP has carried the burden of specifying a standardized IMS-based emergency services framework. Unfortunately, like any other IP-based standards, the IMS-based emergency service framework is prone to Distributed Denial of Service (DDoS) attacks. We propose in this work, a simple but efficient solution that can prevent certain types of such attacks by creating firewall pinholes that regular clients will surely be able to pass in contrast to the attackers clients. Our solution was implemented, tested in an appropriate testbed, and its efficiency was proven.
ATTACK PATTERNS FOR DETECTING AND PREVENTING DDOS AND REPLAY ATTACKS
A.MADHURI,,A.RAMANA LAKSHMI
International Journal of Engineering Science and Technology , 2010,
Abstract: In this paper, we discuss the methods for detecting and preventing the DDoS Attacks and Replay Attacks, which have been posing the problems for the Internet. We explained a scheme AMFDR (AttackPatterns for Marking Filtering DoS and Replay attacks) that identifies the attack packets from the packets that are sent by legitimate users and filters the attack packets. A Denial of service attack is generally launched to make a service unavailable even to an unauthorized user. If this attack uses many computers across the world, it is called Distributed Denial of service attack. Replay attack is retransmission of a data transmission which used to gain authentication in a fraudulent manner. These replayed packets or attack packets are identified. This scheme is less expensive and the implementation of this scheme needs minimal interaction with routers. The scheme is like firewall system, so that the occurrence of an attack is recognized quickly and a punitive action is taken without any loss genuine packets.
Pebble Delivery for Inside-Out Planet Formation  [PDF]
Xiao Hu,Jonathan C. Tan,Sourav Chatterjee
Physics , 2014, DOI: 10.1017/S1743921314007856
Abstract: Inside-Out Planet Formation (IOPF; Chatterjee & Tan 2014, hereafter CT14) is a scenario for sequential in situ planet formation at the pressure traps of retreating dead zone inner boundaries (DZIBs) motivated to explain the many systems with tightly packed inner planets (STIPs) discovered by Kepler. The scenario involves build-up of a pebble-dominated protoplanetary ring, supplied by radial drift of pebbles from the outer disk. It may also involve further build-up of planetary masses to gap-opening scales via continued pebble accretion. Here we study radial drift & growth of pebbles delivered to the DZIB in fiducial IOPF disk models.
The inside-out view on neutron star magnetospheres  [PDF]
K. Glampedakis,S. K. Lander,N. Andersson
Physics , 2013, DOI: 10.1093/mnras/stt1814
Abstract: We construct hydromagnetic neutron star equilibria which allow for a non-zero electric current distribution in the exterior. The novelty of our models is that the neutron star's interior field is in equilibrium with its magnetosphere, thus bridging the gap between previous work in this area which either solves for the interior assuming a vacuum exterior or solves for the magnetosphere without modelling the star itself. We consider only non-rotating stars in this work, so our solutions are most immediately applicable to slowly-rotating systems such as magnetars. Nonetheless, we demonstrate that magnetospheres qualitatively resembling those expected for both magnetars and pulsars are possible within our framework. The "inside-out" approach taken in this paper should be more generally applicable to rotating neutron stars, where the interior and exterior regions are again not independent but evolve together.
Holography of the BTZ Black Hole, Inside and Out  [PDF]
Anton de la Fuente,Raman Sundrum
Physics , 2013, DOI: 10.1007/JHEP09(2014)073
Abstract: We propose a 1+1 dimensional CFT dual structure for quantum gravity and matter on the extended 2+1 dimensional BTZ black hole, realized as a quotient of the Poincare patch of AdS$_3$. The quotient spacetime includes regions beyond the singularity, "whiskers", containing timelike and lightlike closed curves, which at first sight seem unphysical. The spacetime includes the usual AdS-asymptotic boundaries outside the horizons as well as boundary components inside the whiskers. We show that local boundary correlators with some endpoints in the whisker regions: (i) are a protected class of amplitudes, dominated by effective field theory even when the associated Witten diagrams appear to traverse the singularity, (ii) describe well-defined diffeomorphism-invariant quantum gravity amplitudes in BTZ, (iii) sharply probe some of the physics inside the horizon but outside the singularity, and (iv) are equivalent to correlators of specific non-local CFT operators in the standard thermofield entangled state of two CFTs. In this sense, the whisker regions can be considered as purely auxiliary spacetimes in which these useful non-local CFT correlators can be rendered as local boundary correlators, and their diagnostic value more readily understood. Our results follow by first performing a novel reanalysis of the Rindler view of standard AdS/CFT duality on the Poincare patch of AdS, followed by exploiting the simple quotient structure of BTZ which turns the Rindler horizon into the BTZ black hole horizon. While most of our checks are within gravitational effective field theory, we arrive at a fully non-perturbative CFT proposal to probe the UV-sensitive approach to the singularity.
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