Trojan

About: Trojan is a research topic. Over the lifetime, 2028 publications have been published within this topic receiving 33209 citations.

The Pan-STARRS 1 Discoveries of five new Neptune Trojans

Abstract: In this work, we report the detection of seven Neptune Trojans (NTs) in the Pan-STARRS 1 (PS1) survey. Five of these are new discoveries, consisting of four L4 Trojans and one L5 Trojan. Our orbital simulations show that the L5 Trojan stably librates for only several million years. This suggests that the L5 Trojan must be of recent capture origin. On the other hand, all four new L4 Trojans stably occupy the 1:1 resonance with Neptune for more than 1 Gyr. They can, therefore, be of primordial origin. Our survey simulation results show that the inclination width of the NT population should be between 7° and 27° at >95% confidence, and most likely ~11°. In this paper, we describe the PS1 survey, the Outer Solar System pipeline, the confirming observations, and the orbital/physical properties of the new NTs.

On the inclinations of the Jupiter Trojans

Abstract: Jupiter Trojans are a resonant asteroidal population characterised by photometric colours that are compatible with trans-Neptunian objects, high inclinations, and an asymmetric distribution of the number of asteroids between the two swarms. Different models have been proposed to explain the high inclination of the Trojans and to interpret their relation with the Trans-Neptunian objects, but none of these models can also satisfactorily explain the asymmetry ratio between the number of asteroids in the two swarms. It has recently been found that the asymmetry ratio can arise if Jupiter has migrated inwards through the protoplanetary disc by at least a few astronomical units during its growth. The more numerous population of the leading swarm and the dark photometric colours of the Trojans are natural outcomes of this new model, but simulations with massless unperturbed disc particles led to a flat distribution of the Trojan inclinations and a final total mass of the Trojans that was 3-4 orders of magnitude larger than the current mass. We here investigate the possible origin of the peculiar inclination distribution of the Trojans in the scenario where Jupiter migrates inwards. We analyse different possibilities: (a) the secular evolution of an initially flat Trojan population, (b) the presence of planetary embryos among the Trojans, and (c) capture of the Trojans from a pre-stirred planetesimal population in which Jupiter grows and migrates. We find that the secular evolution of the Trojans and secular perturbations from Saturn do not affect the inclination distribution of the Trojans appreciably, nor is there any significant mass depletion over the age of the Solar System. Embryos embedded in the Trojan swarms, in contrast, can stir the Trojans to their current degree of excitation and can also deplete the swarms efficiently, but it is very difficult to remove all of the massive bodies in 4.5 Gyr of evolution. We propose that the disc where Jupiter's core was forming was already stirred to high inclination values by other planetary embryos competing in the feeding zone of Jupiter's core. We show that the trapped Trojans preserve their high inclination through the gas phase of the protoplanetary disc and that Saturn's perturbations are more effective on highly inclined Trojans, leading to a lower capture efficiency and to a substantial depletion of the swarms during 4.5 Gyr of evolution. (Less)

Malicious circuitry detection using fast timing characterization via test points

Abstract: We develop a region-based timing characterization approach to detect hardware Trojans (HTs) on integrated circuits (ICs). In order to ensure the scalability of the approach, we partition the target IC into well-formed and non-overlapping regions and detect hardware Trojans on all circuit locations by examining the timing properties of the transistor paths. Based on the circuit partition, we insert a minimal number of test points that provide additional observation interfaces for the delay measurements of all circuit locations. Our evaluations on ISCAS and ITC benchmarks show that the region-based Trojan detection via test points can detect hardware Trojans accurately with well controlled area overhead and test time.

The problem of Hardware Trojans detection in System-on-Chip

Abstract: This paper describes a new threat to the security of integrated circuits (ICs) called Hardware Trojans. Such alterations can be embedded in safety critical, security and military systems, such as weapon control systems, battlefield communication systems, information collection and decision making systems, satellite electronics, banking systems, cryptosystems, etc. The reason is the current trend of IC fabrication migration to low-cost foundries, where additional malicious circuits can be inserted by adversary that could result in functional changes and the whole system failure. The goal of the paper is to describe security problem in IC manufacturing, analyze the existed methods with their bottlenecks for effective Trojan detection in large ICs, such as system-on-chips (SoCs).

Hardware Trojan Side-Channels Based on Physical Unclonable Functions

Abstract: The separation design and fabrication process in the semiconductor industry leads to potential threats such as trojan side-channels (TSCs). In this paper we design a new family of TSCs from physical unclonable functions (PUFs). In particular, a dedicated attack on the PRESENT block cipher is described by using our PUF-based TSCs. Finally we analyze the performance of our PUF-based TSCs and discuss other potential applications.