Encrypted statistical machine learning: new privacy preserving methods

We present two new statistical machine learning methods designed to learn on fully homomorphic encrypted (FHE) data. The introduction of FHE schemes following Gentry (2009) opens up the prospect of privacy preserving statistical machine learning analysis and modelling of encrypted data without compromising security constraints. We propose tailored algorithms for applying extremely random forests, involving a new cryptographic stochastic fraction estimator, and na\"{i}ve Bayes, involving a semi-parametric model for the class decision boundary, and show how they can be used to learn and predict from encrypted data. We demonstrate that these techniques perform competitively on a variety of classification data sets and provide detailed information about the computational practicalities of these and other FHE methods.Comment: 39 page

Encrypted accelerated least squares regression.

Information that is stored in an encrypted format is, by definition, usually not amenable to statistical analysis or machine learning methods. In this paper we present detailed analysis of coordinate and accelerated gradient descent algorithms which are capable of fitting least squares and penalised ridge regression models, using data encrypted under a fully homomorphic encryption scheme. Gradient descent is shown to dominate in terms of encrypted computational speed, and theoretical results are proven to give parameter bounds which ensure correctness of decryption. The characteristics of encrypted computation are empirically shown to favour a non-standard acceleration technique. This demonstrates the possibility of approximating conventional statistical regression methods using encrypted data without compromising privacy

Encrypted accelerated least squares regression.

Information that is stored in an encrypted format is, by definition, usually not amenable to statistical analysis or machine learning methods. In this paper we present detailed analysis of coordinate and accelerated gradient descent algorithms which are capable of fitting least squares and penalised ridge regression models, using data encrypted under a fully homomorphic encryption scheme. Gradient descent is shown to dominate in terms of encrypted computational speed, and theoretical results are proven to give parameter bounds which ensure correctness of decryption. The characteristics of encrypted computation are empirically shown to favour a non-standard acceleration technique. This demonstrates the possibility of approximating conventional statistical regression methods using encrypted data without compromising privacy

Plague, Pestilence & Pollution : Berkoff\u27s Collision With Aeschylus and Sophocles

Our humanity is bound to perennial themes in drama, so when a classic play is adapted to \u27suit\u27 contemporary audiences, the revised version will often reflect the zeitgeist of the times in which it was produced. The magic of retrospection then allows us to examine the social and political particulars that influence the adapted as well as the original work. Indeed, Steven Berkoff\u27s reworkings of both Aeschylus\u27 Agamemnon and Sophocles\u27 Oedipus Rex reflect an unsettled and divided British context in the throes of ideological upheaval during the 1970\u27s and early 1980\u27s. While consistent criticism of leadership and political strife in Berkoff\u27s Literature suggests a commitment to socialist ideals, I will also argue that images of death and destruction promote the playwright\u27s didactic humanitarian ends. Allegorical themes of plague and pestilence in Berkoff\u27s plays suggest images of humanity in the thrall of forces assumed to be beyond its control. At the same time, these texts work to empower the audience with the belief that their resistant action has the potential to change the course of history. Similarly, as the polluted and decaying British environment is presented as an antecedent to disease and disorder, Berkoff suggests that localised activity is the basis for positive change. While a thematic focus on curse and the idea of fate illustrates the concept of an individual being \u27polluted\u27 through \u27no real fault of their own\u27, his work suggests that within the microcosm of individual agency lies the answer to the problems of the macrocosm of society. Hence in Chapter 1 I will argue that pollution creates an environment conducive to plague and pestilence. As opposed to other forms of literature, theatre is a living entity capable of communicating via the physical senses; a key principle upon which Berkoff builds his Aesthetic. Following in the footsteps of Antonin Artaud, Bertolt Brecht and Jacques Le Coq, Berkoff taps into the power of the theatre to reach beyond logical thought into the deepest recesses of the mind and will. Consequently, I argue that Berkoff\u27s theatrical predecessors in the field of physical theatre inform his attempts to move beyond traditional notions of what theatre should be, what it should say and how it should say it. In Chapter 2 I will examine Artaud\u27s idea that theatre is like plague in their mutual powers of revelation, transformation and the fact that both are potentially refining social phenomena. Berkoff\u27s collision with Aeschylus and Sophocles works to purge audiences of the festering sores of their apathy and ignorance by challenging the idea that the conditions of their existence are in some way predetermined and thus immutable. Therefore in Chapter 3 I will look to the historical context and specific political agenda of Berkoff\u27s rewritings as well as his radical treatment of persistent dramatic themes in an attempt to gauge their potential for durability. Ultimately, I argue that Berkoff as auteur director, actor and playwright is committed to transcending crippling assumptions and patterns of thought in art as in life

The Experiences of Specialist Nurses Working Within the Uro-oncology Multidisciplinary Team in the United Kingdom.

PURPOSE: United Kingdom prostate cancer nursing care is provided by a variety of urology and uro-oncology nurses. The experience of working in multidisciplinary teams (MDT) was investigated in a national study. DESIGN: The study consisted of a national survey with descriptive statistics and thematic analysis. METHODS: A secondary analysis of a data subset from a UK whole population survey was undertaken (n = 285) of the specialist nursing workforce and the services they provide. Data were collected on the experience of working in the MDT. RESULTS: Forty-five percent of the respondents felt that they worked in a functional MDT, 12% felt that they worked in a dysfunctional MDT, and 3.5% found the MDT meeting intimidating. Furthermore, 34% of the nurses felt that they could constructively challenge all members of the MDT in meetings. Themes emerging from open-ended questions were lack of interest in nonmedical concerns by other team members, ability to constructively challenge decisions or views within the meeting, and little opportunity for patients' wishes to be expressed. CONCLUSIONS: Despite expertise and experience, nurses had a variable, often negative, experience of the MDT. It is necessary to ensure that all participants can contribute and are heard and valued. More emphasis should be given to patients' nonmedical needs