Vote-Independence: A Powerful Privacy Notion for Voting Protocols

International audienceRecently an attack on ballot privacy in Helios has been discovered [20], which is essentially based on copying other voter's votes. To capture this and similar attacks, we extend the classical threat model and introduce a new security notion for voting protocols: Vote-Independence. We give a formal definition and analyze its relationship to established privacy properties such as Vote-Privacy, Receipt-Freeness and Coercion-Resistance. In particular we show that even Coercion-Resistant protocols do not necessarily ensure Vote-Independence

Enforcing Privacy in the Presence of Others: Notions, Formalisations and Relations

Protecting privacy against bribery/coercion is a necessary requirement in electronic services, like e-voting, e-auction and e-health. Domain-specific privacy properties have been proposed to capture this. We generalise these properties as enforced privacy: a system enforces a user's privacy even when the user collaborates with the adversary. In addition, we account for the influence of third parties on a user's privacy. Third parties can help to break privacy by collaborating with the adversary, or can help to protect privacy by cooperating with the target user. We propose independency of privacy to capture the negative privacy impact that third parties can have, and coalition privacy to capture their positive privacy impact. We formally define these privacy notions in the applied pi calculus and build a hierarchy showing their relations

Privacy Enhanced Personal Services for Smart Grids

Millions of people are now increasingly using smart devices at home to improve the quality of their lives. Unfortunately, the smart devices that we use at home for comfort and sim-plicity make our lives more complicated in terms of man-agement due to several issues like mismatching interfaces and complexity of the micro-management. One approach to manage smart homes is to enable the utility provider, which has direct access to electrical devices via smart meters. It is expected that the data collected for the management can also be utilized for other personalized services using other business partners. In this paper, we address these personal-ized services and argue that privacy is a serious consideration for the deployment of the new business ideas. We provide a scientific method to provide new services for smart homes while protecting the privacy-sensitive data. To the best of our knowledge, privacy enhanced new services based on the utilization of smart meter data have not been considered by the research community

Defining privacy for weighted votes, single and multi-voter coercion

Most existing formal privacy definitions for voting protocols are based on observational equivalence between two situations where two voters swap their votes. These definitions are unsuitable for cases where votes are weighted. In such a case swapping two votes can result in a different outcome and both situations become trivially distinguishable. We present a definition for privacy in voting protocols in the applied π-calculus that addresses this problem. Using our model, we are also able to define multi-voter coercion, i.e. situations where several voters are attacked at the same time. Then we prove that under certain realistic assumptions a protocol secure against coercion of a single voter is also secure against coercion of multiple voters. This applies for Receipt-Freeness as well as Coercion-Resistance

Empfehlungen für die Diagnostik und Therapie psychotischer Erkrankungen im Alter [Recommendations for the Diagnosis and Therapy of Psychotic Disorders in the Elderly]

Recommendations for the Diagnosis and Therapy of Psychotic Disorders in the Elderly Abstract. Psychotic disorders in the elderly cover a wide range of causes and manifestations. They often occur as part of a depression, dementia, substance abuse or delirium. While psychosis can occur with a first manifestation in advanced age, many patients with chronic psychotic disorders reach a high age. Many elderly individuals are also affected by cognitive impairment and somatic conditions, making a third-party history most relevant. The associated changes in life and the complexity of the individual situation needs to be integrated into the diagnosis and treatment. The presented recommendations have been developed under the lead of the Swiss Society of Old Age Psychiatry (SGAP) in collaboration with the Swiss Association of Nurses (SBK) and the subcommittees for gerontological and psychiatric nursing of the association of nursing science (VFP) as well as further professional societies. We aim to make current knowledge concerning diagnosis and treatment available to the interprofessional teams working in in- and outpatients' settings

Prêt à Voter providing everlasting privacy

This paper shows how Prêt à Voter can be adjusted in order to provide everlasting privacy. This is achieved by adapting the ballot generation and anonymisation process, such that only unconditional hiding commitments and zero knowledge proofs are published for verification, thus ensuring privacy towards the public. This paper presents a security analysis carried out in a collaboration between computer scientists and legal researchers. On the technical side it is shown that the modified Prêt à Voter provides verifiability, robustness, and everlasting privacy towards the public. Everlasting privacy towards the authorities can be achieved by implementing several organisational measures. A legal evaluation of these measures demonstrates that the level of privacy achieved would be acceptable under German law