An Analysis of Optical Contributions to a Photo-Sensor's Ballistic Fingerprints

Lens aberrations have previously been used to determine the provenance of an image. However, this is not necessarily unique to an image sensor, as lens systems are often interchanged. Photo-response non-uniformity noise was proposed in 2005 by Luk\'a\v{s}, Goljan and Fridrich as a stochastic signal which describes a sensor uniquely, akin to a "ballistic" fingerprint. This method, however, did not account for additional sources of bias such as lens artefacts and temperature. In this paper, we propose a new additive signal model to account for artefacts previously thought to have been isolated from the ballistic fingerprint. Our proposed model separates sensor level artefacts from the lens optical system and thus accounts for lens aberrations previously thought to be filtered out. Specifically, we apply standard image processing theory, an understanding of frequency properties relating to the physics of light and temperature response of sensor dark current to classify artefacts. This model enables us to isolate and account for bias from the lens optical system and temperature within the current model.Comment: 16 pages, 9 figures, preprint for journal submission, paper is based on a thesis chapte

Online grooming and preventive justice

In England and Wales, Section 15 of the Sexual Offences Act (2003) criminalizes the act of meeting a child –someone under 16—after grooming. The question to be pursued in this paper is whether grooming –I confine myself to online grooming—is justly criminalized. I shall argue that it is. One line of thought will be indirect. I shall first try to rebut a general argument against the criminalization of acts that are preparatory to the commission of serious offences. Grooming is one such act, but there are others, sometimes associated with terrorism. According to me, the general argument misapplies certain considerations about autonomy that are alleged to be in force in other areas of criminal law. Contrary to that general argument, criminalization of preparatory acts does not, in general, bypass the agency of citizens. Moreover, the criminalization of preparatory acts can disrupt activity that would have led to very serious crime, and with relatively low costs to the perpetrators, costs that reflect the non-occurrence of the more serious crime. There is evidence that grooming is harmful in itself, and so another point against the general argument is its assumption that preparatory offences are often harmless or at least victimless. There are objections to some of the undercover policing techniques that lead to a Section 15 prosecution, but these objections are not all weighty

Bulk collection, intrusion and domination

The [...] discussion is divided into five sections. In the first, technologies for targeted surveillance will be reviewed, along with the risks of unjustified intrusion they carry. I shall address the question why intrusion is normally morally wrong. This will involve me in discussing the value of privacy and the different zones protected by established informal conventions about privacy. Privacy in the relevant sense is associated with access to information rather than control of information. On the basis of the distinction between access and control, I give reasons in the second section for thinking that bulk collection is not as intrusive as better established technologies used for targeted surveillance. Section 3 distinguishes the NSA and bulk collection from the Stasi and its methods of intelligence collection, and rejects the claim that the two are relevantly similar. In section 4, I introduce a concept from republican theory – that of domination — to articulate a sound line of objection against bulk collection: namely that it contributes to “domination” on a modest scale, that is, a potential for infringing some citizens’ negative liberty, if it is not, as it is not, effectively regulated and overseen. I end by suggesting that the main problem with bulk collection is that too much information surrounding it is classified, wrongly impeding the scrutiny of even security - cleared, democratically elected legislators

Experimental philosophy and the history of philosophy

Contemporary experimental philosophers sometimes use versions of an argument from the history of philosophy to defend the claim that what they do is philosophy. Although experimental philosophers conduct surveys and carry out what appear to be experiments in psychology, making them methodologically different from most analytic philosophers working today, techniques like theirs were not out of the ordinary in the philosophy of the past, early modern philosophy in particular. Or so some of them (Knobe, Nichols, Systma and Livengood) argue. This paper disputes the argument, citing important differences between early modern philosopher-scientists – Descartes, Hobbes and Boyle – and their supposed modern counterparts. Although there is some continuity between early modern philosopher-scientists and the contemporary experimentalists, it is mostly a continuity of interest in empirically informed philosophy, not a distinctively experimental philosoph

The scope of serious crime and preventive justice

I offer an account of serious crime that goes beyond victimizing crimes committed by individuals against other individuals. This approach extends the well-known framework offered by Von Hirsch and Jareborg to include crimes undermining welfare-producing institutions. I then consider how the seriousness of crime justifies preventive measures, including the criminalization of acts preparatory to the commission of serious crime. I shall defend preventive measures, including highly intrusive ones, for the most serious crimes, such as terrorism in the form of mass killing, but I shall take issue with very expansive conceptions of serious crime that include what are intuitively much less serious offences than terrorism or murder. In England and Wales, the Serious Crime Act (2007) lists relevant types of serious crime in its Schedule 1. This and other pieces of serious crime legislation in the UK are discussed critically

Responsibility in the financial crisis

The global financial crisis began in 2007, and we are still feeling its effects. It has involved the collapse or near- collapse of large commercial banks, hugely expensive interventions by governments to guarantee deposits and buy bank assets, a steep decline in bank lending to individuals and businesses, significant falls in consumer activity, both domestic and international, with a resulting reduction in trade. Government indebtedness due to the crisis has resulted in diminished welfare states in Western Europe and a worsening of the position of the worst off in developed countries. In the United States, repossessions of properties rose very markedly after 2006, and members of both low and middle income groups have at times been very badly affected

Emergencies in sober Hobbesianism

Thomas Hobbes might seem an unlikely source for a theory of emergency powers applicable to liberal democracies in our own day. He advocated the concentration of political, judicial, economic and military authority, and was in favour of great latitude for a monarch or assembly in the choice of means to security. His theory demands absolute submission to law on the part of citizens, with no constitutional limitations on what laws can require. 1 The same theory demands preventive measures against sedition, and has a very expansive conception of seditious behavior. What is more, the concentration of power with wide discretion is supposed to be politics as usual

Appeals to experience in Hobbes' science of politics

This paper considers an unusual break from that condescension – in Hobbes’s civil philosophy. Although he claims for his own formulation of civil philosophy a kind of definitiveness and certainty that only geometry has among the sciences, and although both geometry and civil philosophy are supposed to be the products of reason, the necessity of establishing and submitting to the commonwealth is open to a certain sort of confirmation from experience. This is not because Hobbes concedes cognitive authority to sense and memory after all, but because civil philosophy has a rhetorical purpose that a certain kind of appeal to experience helps to achieve

Commentary on Jecker

Jecker’s paper focuses on the value of sex and sexuality in the lives of older people, and she argues that there is nothing wrong with the use of sex robots to realise that value. She concedes that sex robots marketed today are overwhelmingly designed for heterosexual males, and that their appearance corresponds to certain objectionable stereotypes of sexually attractive women, and of exciting sexual practices. Still, she says, sex robots do not have to be like that, and a less stereotype-ridden design could take away the sexism, heterosexualism and ageism of current ones. I am sympathetic to these conclusions. But I believe that they are not general enough, and I want to take issue with the argumentative strategy that leads to them. The conclusions are not general enough, because disability or bad circumstantial luck can lead to the damaging absence of sex in the lives of people from many adult age groups, not just people in their 70s and 80s. Jecker’s paper starts with the case of couples whose sex life deteriorates with old age. But there are also many people, whether disabled or not, who fail to acquire a sex life, and who want one, sometimes desperately. They, too, have a problem that a suitable sex robot might help