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In this paper we demonstrate the power of a model of tile self-assembly based on active glues which can dynamically change state. We formulate the Signal-passing Tile Assembly Model (STAM), based on the model of Padilla, et al. [20] to be asynchronous, allowing any action of turning a glue on or off, attaching a new tile, or breaking apart an assembly to happen in any order. Within this highly generalized model we provide three new solutions to tile self-assembly problems that have been addressed within the abstract Tile Assembly Model and its variants, showing that signal passing tiles allow for substantial improvement across multiple complexity metrics. Our first result utilizes a recursive assembly process to achieve tile-type efficient assembly of linear structures, using provably fewer tile types than what is possible in standard tile assembly models. Our second system of signal-passing tiles simulates any Turing machine with high fuel efficiency by using only a constant number of tiles per computation step. Our third system assembles the discrete Sierpinski triangle, demonstrating that this pattern can be strictly self-assembled within the STAM. This result is of particular interest in that it is known that this pattern cannot self-assemble within a number of well studied tile self-assembly models. Notably, all of our constructions are at temperature 1, further demonstrating that signal-passing confers the power to bypass many restrictions found in standard tile assembly models.

Abstract-Malware is constantly evolving. Although existing countermeasures have success in malware detection, corresponding counter-countermeasures are always emerging. In this study, a counter-countermeasure that avoids network-based detection approaches by camouflaging malicious traffic as an innocuous protocol is presented. The approach includes two steps: Traffic format transformation and side-channel massage (SCM). Formattransforming encryption (FTE) translates protocol syntax to mimic another innocuous protocol while SCM obscures traffic side-channels. The proposed approach is illustrated by transforming Zeus botnet (Zbot) Command and Control (C&C) traffic into smart grid Phasor Measurement Unit (PMU) data. The experimental results show that the transformed traffic is identified by Wireshark as synchrophasor protocol, and the transformed protocol fools current side-channel attacks. Moreover, it is shown that a real smart grid Phasor Data Concentrator (PDC) accepts the false PMU data.

Microgrids are low voltage electric distribution grids with modular distributed energy sources and controllable loads. The DC microgrids avoid DC to AC and AC to DC conversion and minimize transmission and distribution losses. Dynamic energy management systems enhance utilization of renewable energy sources and ensure uninterrupted supply of power to critical loads. Like the traditional transmission and distribution grid, AC and DC microgrids are vulnerable to cyber attacks. Further research is required on the cyber security to leverage the promises and potentials of DC microgrids. This paper discusses security vulnerabilities and some solutions for DC microgrids.

Smart grid technologies such as synchrophasors using Phasor Measurement Units (PMUs), make real-time monitoring, control and data analysis of the electric power grid possible. The PMU network measures voltage and current phasors across the electrical power grid, and sends 'reports' to control centers. Synchrophasor technology enables reliable and efficient power system operation; but may make the system vulnerable to cyberattacks. In this paper, security vulnerabilities found in literature, that are relevant to PMUs, are discussed and mapped to four general attack classes. Known network security vulnerabilities are addressed in hopes of exposing gaps where further research needs to be conducted on PMU networks.Index Terms-Cyber-attacks, data security, phasor measurement units, power system security, smart grid, synchrophasors.