Speculative Return Address Stack Management Revisited

Branch prediction feeds a speculative execution processor core with instructions. Branch mispredictions are inevitable and have negative effects on performance and energy consumption. With the advent of highly accurate conditional branch predictors, nonconditional branch instructions are gaining importance.

Fetch Gating Control through Speculative Instruction Window Weighting

In a dynamic reordering superscalar processor, the front-end fetches instructions and places them in the issue queue. Instructions are then issued by the back-end execution core. Till recently, the front-end was designed to maximize performance without considering energy consumption. The front-end fetches instructions as fast as it can until it is stalled by a filled issue queue or some other blocking structure. This approach wastes energy: (i) speculative execution causes many wrong-path instructions to be fetched and executed, and (ii) back-end execution rate is usually less than its peak rate, but front-end structures are dimensioned to sustained peak performance. Dynamically reducing the front-end instruction rate and the active size of front-end structure (e.g. issue queue) is a required performance-energy trade-off. Techniques proposed in the literature attack only one of these effects.
In previous work, we have proposed Speculative Instruction Window Weighting (SIWW) [21], a fetch gating technique that allows to address both fetch gating and instruction issue queue dynamic sizing. SIWW computes a global weight on the set of inflight instructions. This weight depends on the number and types of inflight instructions (non-branches, high confidence or low confidence branches, ...). The front-end instruction rate can be continuously adapted based on this weight. This paper extends the analysis of SIWW performed in previous work. It shows that SIWW performs better than previously proposed fetch gating techniques and that SIWW allows to dynamically adapt the size of the active instruction queue.

Towards Understanding Man-In-The-Middle Attacks on IEC 60870-5-104 SCADA Networks

This paper investigates cyber attacks on ICS which rely on IEC 60870-5-104 for telecontrol communications. The main focus of the paper is on man-in-the-middle attacks, covering modification and injection of commands, it also details capture and replay attacks. An initial set of attacks are preformed on a local software simulated laboratory. Final experiments and validation of a man-in-the-middle attack are performed in a comprehensive testbed environment in conjunction with an electricity distribution operator.

Empirical evaluation of multi-device profiling side-channel attacks

Side-channel analysis of cryptographic systems can allow for the recovery of secret information by an adversary even where the underlying algorithms have been shown to be provably secure. This is achieved by exploiting the unintentional leakages inherent in the underlying implementation of the algorithm in software or hardware. Within this field of research, a class of attacks known as profiling attacks, or more specifically as used here template attacks, have been shown to be extremely efficient at extracting secret keys. Template attacks assume a strong adversarial model, in that an attacker has an identical device with which to profile the power consumption of various operations. This can then be used to efficiently attack the target device. Inherent in this assumption is that the power consumption across the devices under test is somewhat similar. This central tenet of the attack is largely unexplored in the literature with the research community generally performing the profiling stage on the same device as being attacked. This is beneficial for evaluation or penetration testing as it is essentially the best case scenario for an attacker where the model built during the profiling stage matches exactly that of the target device, however it is not necessarily a reflection on how the attack will work in reality. In this work, a large scale evaluation of this assumption is performed, comparing the key recovery performance across 20 identical smart-cards when performing a profiling attack.

Investigating Cyber-Physical Attacks against IEC 61850 Photovoltaic Inverter Installations

Cyber-attacks against Smart Grids have been found in the real world. Malware such as Havex and BlackEnergy have been found targeting industrial control systems (ICS) and researchers have shown that cyber-attacks can exploit vulnerabilities in widely used Smart Grid communication standards. This paper addresses a deep investigation of attacks against the manufacturing message specification of IEC 61850, which is expected to become one of the most widely used communication services in Smart Grids. We investigate how an attacker can build a custom tool to execute man-in-the-middle attacks, manipulate data, and affect the physical system. Attack capabilities are demonstrated based on NESCOR scenarios to make it possible to thoroughly test these scenarios in a real system. The goal is to help understand the potential for such attacks, and to aid the development and testing of cyber security solutions. An attack use-case is presented that focuses on the standard for power utility automation, IEC 61850 in the context of inverter-based distributed energy resource devices; especially photovoltaic (PV) generators.

Can Leakage Models Be More Efficient? Non-Linear Models in Side Channel Attacks

In the last decade, many side channel attacks have been published in academic literature detailing how to efficiently extract secret keys by mounting various attacks, such as differential or correlation power analysis, on cryptosystems. Among the most efficient and widely utilized leakage models involved in these attacks are the Hamming weight and distance models which give a simple, yet effective, approximation of the power consumption for many real-world systems. These leakage models reflect the number of bits switching, which is assumed proportional to the power consumption. However, the actual power consumption changing in the circuits is unlikely to be directly of that form. We, therefore, propose a non-linear leakage model by mapping the existing leakage model via a transform function, by which the changing power consumption is depicted more precisely, hence the attack efficiency can be improved considerably. This has the advantage of utilising a non-linear power model while retaining the simplicity of the Hamming weight or distance models. A modified attack architecture is then suggested to yield the correct key efficiently in practice. Finally, an empirical comparison of the attack results is presented.

Gramsci, austerity common sense and the attacks on the welfare state: The need to understand and resist the imposition of the global neoliberal agenda and the role of the social work profession.

During the last 30 years governments almost everywhere in the world are furthering a global neoliberal agenda by withdrawing the state from the delivery of services, decreasing social spending and lowering corporate taxation etc. This restructuring has led to a massive transfer of wealth from the welfare state and working class people into capital. In order to legitimize this restructuring conservative governments engage in collective blaming towards their denizens. This presentation will examine some of the well circulated phrases that have been used by the dominant elite in some countries during the last year to legitimize the imposition of austerity measures. Phrases such as, ‘We all partied’ used by the Irish finance minister, Brian Lenihan, to explain the Irish crisis and collectively blame all Irish people, ‘We must all share the pain’, deployed by another Irish Minister Gilmore and the UK coalition administration’s sound bite ‘We are all in this together’, legitimize the imposition of austerity measures. Utilizing the Gramscian concept of common sense (Gramsci, 1971), I call these phrases ‘austerity common sense’. They are austerity common sense because they both reflect and legitimate the austerity agenda. By deploying these phrases, the ruling economic and political elite seek to influence the perception of the people and pre-empt any intention of resistance. The dominant theme of these phrases is that there is no alternative and that austerity measures are somehow self-inflicted and, as such, should not be challenged because we are all to blame. The purpose of this presentation is to explore the “austerity common sense” theme from a Gramscian approach, focus on its implications for the social work profession and discuss the ways to resist the imposition of the global neoliberal agenda.

A speculative systems model of the dynamic interaction among students, faculty and administration in the community college, with particular reference to intrinsic motivation and the teacher-administrator interface

The challenge the community college faces in helping meet the needs of the living open system of society is examined in this study. It is postulated that internalization student outcomes are required by society to reduce entropy and remain self-renewing. Such behavior is characterized as having an intrinsically motivated energy source and displays the seeking and conquering of challenge, the development of reflective knowledge and skill, full use of all capabilities, internal control, growth orientation, high self-esteem, relativistic thinking and competence. The development of a conceptual systems model that suggests how transactions among students, faculty and administration might occur to best meet the needs of internalization outcomes in students, and intrinsic motivation in faculty is a major purpose of this study. It is a speculative model that is based on a synthesis of a wide variety of variables. Empirical evidence, theoretical considerations, and speculative ideas are gathered together from researchers and theoretici.ans who are working on separate answers to questions of intrinsic motivation, internal control and environments that encourage their development. The model considers the effect administrators·have on faculty anq the corresponding effect faculty may have on students. The major concentration is on the administrator--teacher interface.For administrators the model may serve as a guide in planning effective transactions, and establishing system goals. The teacher is offered a means to coordinate actions toward a specific overall objective, and the administrator, teacher and researcher are invited to use the model to experiment, innovate, verify the assumptions on which the model is based, and raise additional hypotheses. Goals and history of the community colleges in Ontario are examined against current problems, previous progress and open system thinking. The nature of the person as a five part system is explored with emphasis on intrinsic motivation. The nature, operation, conceptualization, and value of this internal energy source is reviewed in detail. The current state of society, education and management theory are considered and the value of intrinsically motivating teaching tasks together with "system four" leadership style are featured. Evidence is reviewed that suggests intrinsically motivated faculty are needed, and "system four" leadership style is the kind of interaction-influence system needed to nurture intrinsic motivation in faculty.

Computer "Insecurity" and Viral Attacks : Liability Issues Regarding Unsafe Computer Systems Under Quebec Law

Un résumé en français est également disponible.