Mitigating Branch-Shadowing Attacks on Intel SGX using Control Flow Randomization

Intel Software Guard Extensions (SGX) is a promising hardware-based technology for protecting sensitive computations from potentially compromised system software. However, recent research has shown that SGX is vulnerable to branch-shadowing -- a side channel attack that leaks the fine-grained (branch granularity) control flow of an enclave (SGX protected code), potentially revealing sensitive data to the attacker. The previously-proposed defense mechanism, called Zigzagger, attempted to hide the control flow, but has been shown to be ineffective if the attacker can single-step through the enclave using the recent SGX-Step framework. Taking into account these stronger attacker capabilities, we propose a new defense against branch-shadowing, based on control flow randomization. Our scheme is inspired by Zigzagger, but provides quantifiable security guarantees with respect to a tunable security parameter. Specifically, we eliminate conditional branches and hide the targets of unconditional branches using a combination of compile-time modifications and run-time code randomization. We evaluated the performance of our approach by measuring the run-time overhead of ten benchmark programs of SGX-Nbench in SGX environment

Space shuttle electromagnetic environment experiment. Phase A: Definition study

Methods for carrying out measurements of earth electromagnetic environment using the space shuttle as a measurement system platform are herein reported. The goal is to provide means for mapping intentional and nonintentional emitters on earth in the frequency range 0.4 to 40 GHz. A survey was made of known emitters using available data from national and international regulatory agencies, and from industry sources. The spatial distribution of sources, power levels, frequencies, degree of frequency re-use, etc., found in the survey, are here presented. A concept is developed for scanning the earth using a directive antenna whose beam is made to rotate at a fixed angle relative to the nadir; the illuminated area swept by the beam is of the form of cycloidal annulus over a sphere. During the beam's sojourn over a point, the receiver sweeps in frequency over ranges in the order of octave width using sweeping filter bandwidths sufficient to give stable readings

Venus cusp observations during 1969 - Synopsis of results

Venus cusp observations during 196

ANALYTICAL SOLUTION FOR SPEED TO ACHIEVE A DESIRED OPERATING POINT FOR A GIVEN FAN OR PUMP

The Affinity Laws for fans (and pumps) provide a way of determining new fan or pump speed given fan or pump performance curve data and a desired operating point (combination of flow rate and pressure) that does not fall on the curve. However, the affinity law calculations require using a point on the curve (hereafter referred to as the “basic point”) to determine the new speed. Most references regarding the Affinity Laws do not give a clear description of the method for determining the “basic point”, and improper selection of this point can affect the results considerably. This article describes the requirements for the “basic point,” and presents an analytical solution to determine the “basic point” and the desired operating speed for the fan or pump to operate at the desired operating point conditions

ANALYTICAL SOLUTION FOR SPEED TO ACHIEVE A DESIRED OPERATING POINT FOR A GIVEN FAN OR PUMP

The Affinity Laws for fans (and pumps) provide a way of determining new fan or pump speed given fan or pump performance curve data and a desired operating point (combination of flow rate and pressure) that does not fall on the curve. However, the affinity law calculations require using a point on the curve (hereafter referred to as the “basic point”) to determine the new speed. Most references regarding the Affinity Laws do not give a clear description of the method for determining the “basic point”, and improper selection of this point can affect the results considerably. This article describes the requirements for the “basic point,” and presents an analytical solution to determine the “basic point” and the desired operating speed for the fan or pump to operate at the desired operating point conditions

METHOD AND APPARATUS FOR OBJECTIVE EVALUATION OF PATENT AMBULATION, BALANCE AND WEIGHT BEARNG STATUS

A walker is provided which is equipped with detectors for measuring various loads and torques placed thereon by a user including right side and left side loads as well as torque loads on the handles of the walker and having time and distance detectors to allow the ambulation status of a user to be progressively monitored by medical personnel

Space shuttle electromagnetic environment experiment. Phase A: Definition study

A program is discussed which develops a concept for measuring the electromagnetic environment on earth with equipment on board an orbiting space shuttle. Earlier work on spaceborne measuring experiments is reviewed, and emissions to be expected are estimated using, in part, previously gathered data. General relations among system parameters are presented, followed by a proposal on spatial and frequency scanning concepts. The methods proposed include a nadir looking measurement with small lateral scan and a circularly scanned measurement looking tangent to the earth's surface at the horizon. Antenna requirements are given, assuming frequency coverage from 400 MHz to 40 GHz. For the low frequency range, 400-1000 MHz, a processed, thinned array is proposed which will be more fully analyzed in the next phase of the program. Preliminary hardware and data processing requirements are presented

A 24-Year-Old Man with Spontaneous Right Tension Pneumothorax Presenting with Abdominal Pain with an Initial Symptomatic Diagnosis of Acute Pancreatitis.

BACKGROUND Tension pneumothorax (TP) is a medical emergency resulting in air accumulation in the pleural cavity of the affected side. Later, this air applies pressure on the mediastinal structures, leading to a shift of these structures toward the contralateral side. This shift results in a picture of obstructive shock with a possibly fatal consequence if not detected and treated early. Treatment should not await radiological confirmation, and the red flags in the history and physical examination are enough to proceed with decompressing the affected hemithorax with a large-bore needle. Usually, patients with TP present to the Emergency Department with pleuritic chest pain and shortness of breath, but rare presentations are still possible. CASE REPORT We report a case of a 24-year-old male patient with TP who presented to the Emergency Department with severe epigastric abdominal pain with a clinical picture of acute pancreatitis. X-ray showed a right-sided TP. Immediately, we performed a needle decompression followed by chest tube insertion. Four days later, the patient was discharged home uneventfully. CONCLUSIONS In this case report, we aim to draw the attention of physicians in the Emergency Department to the need to consider the possibility of upper abdominal pain elicited by chest pathologies. Furthermore, we need to investigate the effect of TP on coronary perfusion

Asymptotic information leakage under one-try attacks

We study the asymptotic behaviour of (a) information leakage and (b) adversary’s error probability in information hiding systems modelled as noisy channels. Specifically, we assume the attacker can make a single guess after observing n independent executions of the system, throughout which the secret information is kept fixed. We show that the asymptotic behaviour of quantities (a) and (b) can be determined in a simple way from the channel matrix. Moreover, simple and tight bounds on them as functions of n show that the convergence is exponential. We also discuss feasible methods to evaluate the rate of convergence. Our results cover both the Bayesian case, where a prior probability distribution on the secrets is assumed known to the attacker, and the maximum-likelihood case, where the attacker does not know such distribution. In the Bayesian case, we identify the distributions that maximize the leakage. We consider both the min-entropy setting studied by Smith and the additive form recently proposed by Braun et al., and show the two forms do agree asymptotically. Next, we extend these results to a more sophisticated eavesdropping scenario, where the attacker can perform a (noisy) observation at each state of the computation and the systems are modelled as hidden Markov models

Stellenwert der endoskopischen Axilladissektion beim invasiven Mammakarzinom

Zusammenfassung: Grundlagen: Die Axilladissektion liefert zuverlässige prognostische Information, bestimmt mehrheitlich die adjuvante Therapie und reduziert die axillären Tumorrezidive. Die Morbidität nach Axilladissektion kann jedoch nicht vernachlässigt werden (sensible Störungen, Schmerzen, motorische Schwäche, Lymphödem). Patientinnen mit kleinen Tumoren (pT1a, b, c) könnten von neueren weniger invasiven Verfahren (endoskopische Axilladissektion) oder von selektiveren Methoden (Sentinel-lymph-node-Procedere) profitieren. In dieser prospektiven Studie wurde die axilloskopische Lymphadenektomie evaluiert. Methodik: 55 klinisch nodal negative Patientinnen (Durchschnittsalter: 60 Jahre [30 bis 86 Jahre]) wurden von einem Chirurgen endoskopisch operiert (Januar 1996 bis Juni 1998). Nach Liposuktion des axillären Fettkörpers wurden die Lymphknoten von Level I+II identifiziert und unter direkter endoskopischer Sicht reseziert (erfolgreiches Verfahren in 95 %: n=52). Die Patientinnen wurden entsprechend dem Nachsorgeschema alle 4 Monate kontrolliert. Nach einer mittleren Beobachtungszeit von 22 Monaten (7 bis 37 Monate; n=51 [eine Patientin verweigerte die Nachsorge]) wurden die Patientinnen mit einem Evaluationsfragebogen, einem Interview und einer klinischen Untersuchung (inklusiv Schultergelenksfunktion, Zirkumferenzmessungen der oberen Extremität) nachkontrolliert. Ergebnisse: Durchschnittlich wurden 13,3 (5 bis 25) Lymphknoten endoskopisch entfernt. Nodal positive Lymphknoten wurden in 31 % (n=16) beobachtet. Der Durchschnittswert der positiven Lymphknoten/Patientin betrug 3,1 (1 bis 10). Acht Serome (15 %) mußten in der frühpostoperativen Phase punktiert werden. Es traten keine Hämatome, jedoch ein Infekt in der Axilla nach Chemotherapie auf (2 %). Nach einer mittleren Beobachtungszeit von 22 Monaten (7 bis 37 Monate) konnten keine axillären Rezidive nachgewiesen werden. Eine subkutane Implantationsmetastase in der Narbe eines Trokarkanals (1/55, 2 %) wurde diagnostiziert und reseziert. Klinisch traten keine Lymphödeme auf. Die frühe Mobilisation des Schultergelenkes war subjektiv und objektiv gut. Schlußfolgerungen: Die durchschnittlich 13 axilloskopisch entfernten Lymphknoten entsprechen der Anzahl resezierter Lymphknoten bei offener Axilladissektion. Die Morbidität dieses in Evaluation begriffenen Verfahrens ist niedrig. Nach einer mittleren Beobachtungszeit von 22 Monaten wurde ein Implantationsrezidiv im subkutanen Kanal des anterioren Arbeitstrokar nachgewiesen. Eine längere Beobachtungszeit ist nötig, um die Technik empfehlen zu können. Es zeichnet sich ab, daß die endoskopische, axilläre Lymphknotendissektion durch das selektivere Sentinel-lymph-node-Verfahren abgelöst wir