This is Not an Attack on Wave

Very recently, a preprint ``Cryptanalysis of the Wave Signature Scheme\u27\u27, eprint 2018/1111, appeared claiming to break Wave ``Wave: A New Code-Based Signature Scheme\u27\u27, eprint 2018/996. We explain here why this claim is incorrect

The effect of waves on rubble-mound structures

For thousands of years breakwaters have been built at or near the coast to protect harbors or coastlines from wave attack. One of the earliest known harbor protection schemes was devised in about 2000 B.C. for the Port of Pharos on the open coast of Egypt; it had a rubble-mound breakwater approximately 8500 ft long composed of large blocks of stone with smaller stone filling the spaces between blocks (Savile 1940). Until the development of experimental laboratory techniques to investigate the effect of waves on breakwaters, these structures were designed primarily from experience gained from other similar structures. It is the purpose of this review to discuss various aspects of the hydrodynamics of wave attack on such structures and the relation of certain analytic considerations and experimental results to the design of a rubble-mound. A breakwater built as a rubble-mound is constructed by placing material of various sizes layer by layer (or unit by unit) until the desired cross-section shape is achieved. Generally, the units are not structurally connected, so that the integrity of the rubble-mound depends on features such as the weight of the material, the interlocking nature of the material, and the cross section of the structure. Usually the structure is built with material graded from smaller sizes in the core to larger material armoring the face against wave attack. The armor layer may be composed of quarry-stone, if it is available in the required sizes and is economically feasible to use. When these conditions are not met, specially designed concrete units for armoring the face of the rubble-mound have been developed that tend to interlock better than rock when properly placed; hence, it may be possible to use armor units lighter than the required quarry-stone. Over the years numerous geometric shapes have been developed for such armor units, with each shape generally introduced in an attempt to improve on the interlocking characteristics of its predecessors. To mention only a few, various names used for different units are: tribars, tetrapods, quadripods, and dolosse. A brief description of two of these is presented; for a more detailed discussion of shape along with drawings of the units the interested reader is directed to CERC (1966) and Hudson(1974). Tribars, which consist basically of three circular cylinders connected by a yoke of three cylinders, are usually placed in a uniform geometric pattern on the face of the rubble-mound. Dolosse are shaped like the letter "H" with the vertical legs rotated 90° to each other, and are generally placed randomly on a rubble-mound face. It is the effective interlocking of dolosse that leads to the use of random placement techniques. Obviously an important aspect in the design of a rubble-mound is its stability under wave attack. This subject is discussed in detail, along with descriptions of the basis for certain design approaches currently used. The support of these design criteria as well as their limitations are discussed with reference to available experimental data. Three other aspects of the effect of waves on rubble-mounds are treated in this review: wave run-up, transmission, and overtopping. Run-up is defined as the vertical height above still water level to which waves incident upon a structure can be expected to travel up the face of the structure. Wave run-up is important in defining both the amount of wave energy transmitted over and through permeable rubble-mounds and also the quantity of water that may be expected to overtop the structure. In each of the following sections the discussion is directed toward understanding the fluid-mechanic aspects of the various problems and the features and the shortcomings of analytical and experimental models used in connection with the design of breakwaters constructed as rubble-mounds

Information transfer by quantum matterwave modulation

Classical communication schemes that exploit wave modulation are the basis of the information era. The transfer of information based on the quantum properties of photons revolutionized these modern communication techniques. Here we demonstrate that also matterwaves can be applied for information transfer and that their quantum nature provides a high level of security. Our technique allows transmitting a message by a non-trivial modulation of an electron matterwave in a biprism interferometer. The data is encoded by a Wien filter introducing a longitudinal shift between separated matterwave packets. The transmission receiver is a delay line detector performing a dynamic contrast analysis of the fringe pattern. Our method relies on the Aharonov-Bohm effect and has no light optical analog since it does not shift the phase of the electron interference. A passive eavesdropping attack will cause decoherence and terminating the data transfer. This is demonstrated by introducing a semiconducting surface that disturbs the quantum state by Coulomb interaction and reduces the contrast. We also present a key distribution protocol based on the quantum nature of the matterwaves that can reveal active eavesdropping

Geosynthetics in hydraulic and coastal engineering: filters, revetments and sand filled structures

The paper deals with 2 applications of geotextiles in coastal and hydraulic engineering: Geotextiles in filters and revetments, and in sand filled structures. Geotextiles are often replacing granular filters. However, they have different properties than a granular filter. For a the application of geotextiles in revetments, the consequences of the different properties will be shown: How permeability is influenced by a geotextile and what can be the consequences of the weight differences between granular and geotextile filters. In another application, the filter properties of geotextiles are only secondary. In geotextile tubes and containers the geotextile is used as ‘wrapping material’ to create large units that will not erode during wave attack. The structures with geotextile tubes and containers serve as an alternative for rock based structures. The first of these structures were more or less constructed by trial and error, but research on the shape of the structures, the stability under wave attack and the durability of the used material has given the possibility to use design tools for these structures. Recently also the morphological aspects of these structures have been investi-gated. This is of importance because regularly structures with geotextile tubes fail due to insufficient toe protection against the scour hole that develops in front of the structure, leading to undermining of the structure. Recent research in the Delta Flume of Deltares and the Large Wave Flume in Hannover has led to better understanding what mechanisms determine the stability under wave attack. It is shown that therefore also the degree of filling is of importance and the position of the water level with respect to the tube has a large influence

Efficient And Secure Key Distribution Protocol For Wireless Sensor Networks

Modern wireless sensor networks have adopted the IEEE 802.15.4 standard. This standard defines the first two layers, the physical and medium access control layers; determines the radio wave used for communication, and defines the 128-bit advanced encryption standard (AES-128) for encrypting and validating transmitted data. However, the standard does not specify how to manage, store, or distribute encryption keys. Many solutions have been proposed to address this problem, but the majority are impractical in resource-constrained devices such as wireless sensor nodes or cause degradation of other metrics. Therefore, we propose an efficient and secure key distribution protocol that is simple, practical, and feasible to implement on resource-constrained wireless sensor nodes. We conduct simulations and hardware implementations to analyze our work and compare it to existing solutions based on different metrics, such as energy consumption, storage overhead, key connectivity, replay attack, man-in-the-middle attack, and resiliency to node capture attack. Our findings show that the proposed protocol is secure and more efficient than other solutions

Notes on Recent Approaches Concerning the Kirchhoff-Law-Johnson-Noise-based Secure Key Exchange

We critically analyze the results and claims in [Physics Letters A 373 (2009) 901-904]. We show that the strong security leak appeared in the simulations is only an artifact and not caused by "multiple reflections". Since no wave modes exist at cable length of 5% of the shortest wavelength of the signal, no wave is present to reflect it. In the high wave impedance limit, the conditions used in the simulations are heavily unphysical (requiring cable diameters up to 28000 times greater than the measured size of the known universe) and the results are modeling artifacts due to the unphysical values. At the low cable impedance limit, the observed artifacts are due to violating the recommended (and tested) conditions by neglecting the cable capacitance restrictions and using about 100 times longer cable than recommended without cable capacitance compensation arrangement. We implement and analyze the general circuitry of Liu's circulator and confirm that they are conceptually secure against passive attacks. We introduce an asymmetric, more robust version without feedback loop. Then we crack all these systems by an active attack: a circulator-based man-in-the middle attack. Finally, we analyze the proposed method to increase security by dropping only high-risk bits. We point out the differences between different types of high-risk bits and show the shortage of this strategy for some simple key exchange protocols.Comment: Accepted for publication in Physics Letters A on May 29, 2009. In the present version, DOI and acceptance info is added in the pdf file, to

Stress Waves in Rocks and their Effects on Rock Breakage

In these experimental studies the authors have chiefly investigated the characteristics of the stress waves in rocks caused by detonators or explosives. The research consisted of two parts. In the first part, we have treated mainly the phenomena which accompany the detonator's attack and have discussed the dynamic characteristics of rocks under such impulsive loadings. The following results were obtained from this part of the investigation. The values of Young's moduli for rocks obtained dynamically are about two or three times greater than those obtained statically. The dynamic strengths of rocks are also greater than the static ones, but the difference seems to be not so great as in the case of metals. Moreover, it is an interesting result that various shock effects appear in accordance with the physical properties of rocks. In the second part we advanced to a study of the phenomena accompanying an explosive's attack and observed chiefly the changes in the propagation velocities of the induced stress waves near the explosion point. The results obtained can be summarized as follows. From the results obtained concerning the changes in the velocity of propagation of the stress waves with distance, a plastic wave of higher order seems to exist in the region very near the point of explosion and the appearance of the plastic wave seems to depend not only on the physical characteristics of the rocks but also on the brisance of the explosives. The compressibility of a rock under impulsive high pressure is peculiar to the physical properties of the rock, and it has no relation to the natures of the explosive. The peak pressure of the wave front decreases very rapidly with distance, and only within a few centimeters of the point of explosion do the explosives develop a different high pressure in proportion to their brisances

An Effective Approach for Mobile ad hoc Network via I-Watchdog Protocol

Mobile ad hoc network (MANET) is now days become very famous due to their fixed infrastructure-less quality and dynamic nature. They contain a large number of nodes which are connected and communicated to each other in wireless nature. Mobile ad hoc network is a wireless technology that contains high mobility of nodes and does not depend on the background administrator for central authority, because they do not contain any infrastructure. Nodes of the MANET use radio wave for communication and having limited resources and limited computational power. The Topology of this network is changing very frequently because they are distributed in nature and self-configurable. Due to its wireless nature and lack of any central authority in the background, Mobile ad hoc networks are always vulnerable to some security issues and performance issues. The security imposes a huge impact on the performance of any network. Some of the security issues are black hole attack, flooding, wormhole attack etc. In this paper, we will discuss issues regarding low performance of Watchdog protocol used in the MANET and proposed an improved Watchdog mechanism, which is called by I-Watchdog protocol that overcomes the limitations of Watchdog protocol and gives high performance in terms of throughput, delay

An Effective Approach for Mobile ad hoc Network via I-Watchdog Protocol

Mobile ad hoc network (MANET) is now days become very famous due to their fixed infrastructure-less quality and dynamic nature. They contain a large number of nodes which are connected and communicated to each other in wireless nature. Mobile ad hoc network is a wireless technology that contains high mobility of nodes and does not depend on the background administrator for central authority, because they do not contain any infrastructure. Nodes of the MANET use radio wave for communication and having limited resources and limited computational power. The Topology of this network is changing very frequently because they are distributed in nature and self-configurable. Due to its wireless nature and lack of any central authority in the background, Mobile ad hoc networks are always vulnerable to some security issues and performance issues. The security imposes a huge impact on the performance of any network. Some of the security issues are black hole attack, flooding, wormhole attack etc. In this paper, we will discuss issues regarding low performance of Watchdog protocol used in the MANET and proposed an improved Watchdog mechanism, which is called by I-Watchdog protocol that overcomes the limitations of Watchdog protocol and gives high performance in terms of throughput, delay