66,389 research outputs found

    Measuring the attack surfaces of two FTP daemons

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    Software consumers often need to choose between different software that provide the same functionality. Today, se-curity is a quality that many consumers, especially system administrators, care about and will use in choosing one soft-ware system over another. An attack surface metric is a security metric for comparing the relative security of simi-lar software systems [8]. The measure of a system’s attack surface is an indicator of the system’s security: given two systems, we compare their attack surface measurements to decide whether one is more secure than another along each of the following three dimensions: methods, channels, and data. In this paper, we use the attack surface metric to mea-sure the attack surfaces of two open source FTP daemons: ProFTPD 1.2.10 and Wu-FTPD 2.6.2. Our measurements show that ProFTPD is more secure along the method dimen-sion, ProFTPD is as secure as Wu-FTPD along the channel dimension, and Wu-FTPD is more secure along the data di-mension. We also demonstrate how software consumers can use the attack surface metric in making a choice between the two FTP daemons

    Estimating the cost of generic quantum pre-image attacks on SHA-2 and SHA-3

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    We investigate the cost of Grover's quantum search algorithm when used in the context of pre-image attacks on the SHA-2 and SHA-3 families of hash functions. Our cost model assumes that the attack is run on a surface code based fault-tolerant quantum computer. Our estimates rely on a time-area metric that costs the number of logical qubits times the depth of the circuit in units of surface code cycles. As a surface code cycle involves a significant classical processing stage, our cost estimates allow for crude, but direct, comparisons of classical and quantum algorithms. We exhibit a circuit for a pre-image attack on SHA-256 that is approximately 2153.82^{153.8} surface code cycles deep and requires approximately 212.62^{12.6} logical qubits. This yields an overall cost of 2166.42^{166.4} logical-qubit-cycles. Likewise we exhibit a SHA3-256 circuit that is approximately 2146.52^{146.5} surface code cycles deep and requires approximately 2202^{20} logical qubits for a total cost of, again, 2166.52^{166.5} logical-qubit-cycles. Both attacks require on the order of 21282^{128} queries in a quantum black-box model, hence our results suggest that executing these attacks may be as much as 275275 billion times more expensive than one would expect from the simple query analysis.Comment: Same as the published version to appear in the Selected Areas of Cryptography (SAC) 2016. Comments are welcome

    Calculation of laminar heating rates on three-dimensional configurations using the axisymmetric analogue

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    A theoretical method was developed for computing approximate laminar heating rates on three dimensional configurations at angle of attack. The method is based on the axisymmetric analogue which is used to reduce the three dimensional boundary layer equations along surface streamlines to an equivalent axisymmetric form by using the metric coefficient which describes streamline divergence (or convergence). The method was coupled with a three dimensional inviscid flow field program for computing surface streamline paths, metric coefficients, and boundary layer edge conditions

    Effect of nozzle and vertical-tail variables on the performance of a 3-surface F-15 model at transonic Mach numbers

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    An investigation was conducted in the Langley 16 foot transonic tunnel to determine the longitudinal aerodynamic characteristics of twin two dimensional nozzles and twin baseline axisymmetric nozzles installed on a fully metric 0.047 scale model of the F-15 three surface configuration (canards, wing, horizontal tails). The effects on performance of two dimensional nozzle in flight thrust reversing, locations and orientation of the vertical tails, and deflections of the horizontal tails were also determined. Test data were obtained at static conditions and at Mach numbers from 0.60 to 1.20 over an angle of attack range from -2 deg to 15 deg. Nozzle pressure ratio was varied from jet off to about 6.5

    Effect of thrust reverser operation on the lateral-directional characteristics of a three-surface F-15 model at transonic speeds

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    An investigation was conducted in the Langley 16 Foot Transonic Tunnel to determine the lateral directional aerodynamic characteristics of a fully metric 0.04 scale model of the F-15 three surface configuration (canards, horizontal tails) with twin two dimensional nozzles and twin axisymmetric nozzles installed. The effects of two dimensional nozzle in flight thrust reversing and rudder deflection were also determined. Test data were obtained at static conditions and at Mach numbers from 0.60 to 1.20 over an angle of attack range from -2 deg to 15 deg. Reynolds number varied from 2.6 million to 3.8 million. Angle of sideslip was set at approximately 0 deg and -5 deg for all configurations and at -10 deg for selected configurations

    Attack-Surface Metrics, OSSTMM and Common Criteria Based Approach to “Composable Security” in Complex Systems

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    In recent studies on Complex Systems and Systems-of-Systems theory, a huge effort has been put to cope with behavioral problems, i.e. the possibility of controlling a desired overall or end-to-end behavior by acting on the individual elements that constitute the system itself. This problem is particularly important in the “SMART” environments, where the huge number of devices, their significant computational capabilities as well as their tight interconnection produce a complex architecture for which it is difficult to predict (and control) a desired behavior; furthermore, if the scenario is allowed to dynamically evolve through the modification of both topology and subsystems composition, then the control problem becomes a real challenge. In this perspective, the purpose of this paper is to cope with a specific class of control problems in complex systems, the “composability of security functionalities”, recently introduced by the European Funded research through the pSHIELD and nSHIELD projects (ARTEMIS-JU programme). In a nutshell, the objective of this research is to define a control framework that, given a target security level for a specific application scenario, is able to i) discover the system elements, ii) quantify the security level of each element as well as its contribution to the security of the overall system, and iii) compute the control action to be applied on such elements to reach the security target. The main innovations proposed by the authors are: i) the definition of a comprehensive methodology to quantify the security of a generic system independently from the technology and the environment and ii) the integration of the derived metrics into a closed-loop scheme that allows real-time control of the system. The solution described in this work moves from the proof-of-concepts performed in the early phase of the pSHIELD research and enrich es it through an innovative metric with a sound foundation, able to potentially cope with any kind of pplication scenarios (railways, automotive, manufacturing, ...)
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