Showing papers by "National Security Agency published in 2016"

Adiabatic optimization versus diffusion Monte Carlo methods

Abstract: Most experimental and theoretical studies of adiabatic optimization use stoquastic Hamiltonians, whose ground states are expressible using only real nonnegative amplitudes. This raises a question as to whether classical Monte Carlo methods can simulate stoquastic adiabatic algorithms with polynomial overhead. Here we analyze diffusion Monte Carlo algorithms. We argue that, based on differences between ${L}_{1}$ and ${L}_{2}$ normalized states, these algorithms suffer from certain obstructions preventing them from efficiently simulating stoquastic adiabatic evolution in generality. In practice however, we obtain good performance by introducing a method that we call Substochastic Monte Carlo. In fact, our simulations are good classical optimization algorithms in their own right, competitive with the best previously known heuristic solvers for MAX-$k$-SAT at $k=2,3,4$.

GenCyber: Inspiring the Next Generation of Cyber Stars

Abstract: The GenCyber program strives to help solve the US's shortfall of cybersecurity professionals by reaching kindergarten through 12th grade students and teachers, developing their cybersecurity awareness and stimulating their interest in the cybersecurity field

Performance Management: Embracing Complexity, Evading Reductionism, and Moving to Outcome-Based Approaches

Abstract: Adler et al. ( 2016 ) open with a summary of the business case driving our field to change and close by providing principles for accomplishing that change, where they conclude that “there is no right answer to the ratings question” (p. 244). Lying between the opening and closing sections is a series of arguments for and against today's performance rating status quo, arguments illustrating just what happens when too many years are spent seeking answers along too narrow a path. In this commentary, we provide additional support for the strategy- and outcome-driven approach to performance management advocated in the article. In addition, we offer ideas for what has contributed to getting us and keeping us where we are. Unless we understand what has driven performance ratings research and practice to be the object of an intense and lengthy debate, these same forces may well drive us to carry out years-long experiments of questionable value along similarly narrow paths. We want to offer our views on how to foster outcome-based practice more broadly.

Methods of data reduction for parallel breadth-first search over graphs of connected data elements

Abstract: A method includes receiving, at a master controller, a matrix representing a graph and a first vector, and initializing a counter variable and an array to track dimensionality reduction for the matrix. The method also includes multiplying a subset of the matrix based on the counter variable, by a subset of the first binary vector based on the counter variable. Multiplying includes providing, the vector and a matrix portion to a first processor, and the vector and another portion of the matrix to a second processor. The method also includes, at the processors, multiplying the vectors by the portions of the matrix and returning the results. The method also includes combining the results at the master controller. The method also includes incrementing the counter variable and updating the tracking array for larger dimensionality reduction of the matrix. The method also includes constructing the logical pathway based on the tracking array.

Map Assisted Inertial Navigation

Abstract: The present invention provides an improved method of pedestrian dead reckoning (PDR) and device for performing PDR. An image of the environment to be traversed by the pedestrian is used to define states associated with the PDR environment. The image is utilized to constrain error in the estimated location of the pedestrian. Pairs of states are identified and the characteristics of the defined states are utilized to define the probabilities of transitioning between states of the pair. Possible pedestrian events which may be observed are also defined and for each pair of states, the possibility of detecting an event given the state transition is determined. After detecting a series of events, the transition probabilities and the event probabilities are utilized to determine a state probability that the pedestrian is in a particular state at each particular time. Utilizing these state probabilities an estimated location is provided at each time.

Split Euler Tours In 4-Regular Planar Graphs

Abstract: Abstract The construction of a homing tour is known to be NP-complete. On the other hand, the Euler formula puts su cient restrictions on plane graphs that one should be able to assert the existence of such tours in some cases; in particular we focus on split Euler tours (SETs) in 3-connected, 4-regular, planar graphs (tfps). An Euler tour S in a graph G is a SET if there is a vertex v (called a half vertex of S) such that the longest portion of the tour between successive visits to v is exactly half the number of edges of G. Among other results, we establish that every tfp G having a SET S in which every vertex of G is a half vertex of S can be transformed to another tfp G′ having a SET S′ in which every vertex of G′ is a half vertex of S′ and G′ has at most one point having a face configuration of a particular class. The various results rely heavily on the structure of such graphs as determined by the Euler formula and on the construction of tfps from the octahedron. We also construct a 2-connected 4-regular planar graph that does not have a SET.

Lower bounds for codimension-1 measure in metric manifolds

Abstract: We establish Euclidean-type lower bounds for the codimension-1 Hausdorff measure of sets that separate points in doubling and linearly locally contractible metric manifolds. This gives a quantitative topological isoperimetric inequality in the setting of metric manifolds, in the sense that lower bounds for the codimension-1 measure of a set depend not on some notion of filling or volume but rather on in-radii of complementary components. As a consequence, we show that balls in a closed, connected, doubling, and linearly locally contractible metric $n$-manifold $(M,d)$ with radius $0 0$ depends only on $n$ and on the doubling and linear local contractibility constants.

Tamper evident cable seal

Abstract: A cable seal is provided for attachment to a cable connector. The cable seal generally includes a base portion and a breakaway portion. The breakaway includes a tooth which is positioned under the cable release lever to prevent removal of the cable connector from a communications port. If removal of the cable seal is desired, a breakaway portion of the cable seal is permanently detached from the remainder of the cable seal evidencing access to the port has been gained.

Building a digital camera fingerprint from cropped or corrupted images

Abstract: A method of identifying a digital camera is disclosed. First and second digital images generated by the camera have dimensions that are not equal. The method includes calculating noise residuals and normalized cross-correlations (NCCs) between the noise residuals corresponding to candidate translations. The method further includes calculating a noise floor and identifying first and second peak values corresponding to translations. The method further includes calculating a peak ratio, determining that the peak ratio exceeds an alignment threshold and calculating a digital camera fingerprint for the digital camera based on the noise residuals and the first translation. The method further includes receiving a digital image, calculating a noise residual of the digital image, and determining that the image was generated by the digital camera based on the noise residual and the fingerprint and generating a record associating the image with the camera.

Analyzing proposals for improving authentication on the TLS-/SSL-protected Web

Abstract: "Secure" Web browsing with HTTPS uses TLS/SSL and X.509 certificates to provide authenticated, confidential communication between Web clients and Web servers. The authentication component of the system has a variety of weaknesses, which have led to a variety of proposals for improving the current environment. In this paper, we survey, analyze, compare and contrast five prominent proposals. To do this, we attempt to systematically capture the properties one might require of such a system: authentication properties, forensics/privacy properties, usability properties and pragmatic properties. Enumerating these properties is an important part of understanding these proposals and the nature of the authentication problem for the secure Web. Finally, we offer a few conclusions and suggestions pertaining to these proposals and possible future directions of research.