111,268 research outputs found

    Anonymous subject identification and privacy information management in video surveillance

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    The widespread deployment of surveillance cameras has raised serious privacy concerns, and many privacy-enhancing schemes have been recently proposed to automatically redact images of selected individuals in the surveillance video for protection. Of equal importance are the privacy and efficiency of techniques to first, identify those individuals for privacy protection and second, provide access to original surveillance video contents for security analysis. In this paper, we propose an anonymous subject identification and privacy data management system to be used in privacy-aware video surveillance. The anonymous subject identification system uses iris patterns to identify individuals for privacy protection. Anonymity of the iris-matching process is guaranteed through the use of a garbled-circuit (GC)-based iris matching protocol. A novel GC complexity reduction scheme is proposed by simplifying the iris masking process in the protocol. A user-centric privacy information management system is also proposed that allows subjects to anonymously access their privacy information via their iris patterns. The system is composed of two encrypted-domain protocols: The privacy information encryption protocol encrypts the original video records using the iris pattern acquired during the subject identification phase; the privacy information retrieval protocol allows the video records to be anonymously retrieved through a GC-based iris pattern matching process. Experimental results on a public iris biometric database demonstrate the validity of our framework

    Blindspot: Indistinguishable Anonymous Communications

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    Communication anonymity is a key requirement for individuals under targeted surveillance. Practical anonymous communications also require indistinguishability - an adversary should be unable to distinguish between anonymised and non-anonymised traffic for a given user. We propose Blindspot, a design for high-latency anonymous communications that offers indistinguishability and unobservability under a (qualified) global active adversary. Blindspot creates anonymous routes between sender-receiver pairs by subliminally encoding messages within the pre-existing communication behaviour of users within a social network. Specifically, the organic image sharing behaviour of users. Thus channel bandwidth depends on the intensity of image sharing behaviour of users along a route. A major challenge we successfully overcome is that routing must be accomplished in the face of significant restrictions - channel bandwidth is stochastic. We show that conventional social network routing strategies do not work. To solve this problem, we propose a novel routing algorithm. We evaluate Blindspot using a real-world dataset. We find that it delivers reasonable results for applications requiring low-volume unobservable communication.Comment: 13 Page

    Use of antenatal clinic surveillance to assess the effect of sexual behavior on HIV prevalence in young women in Karonga district, Malawi.

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    BACKGROUND: Antenatal clinic (ANC) surveillance is the primary source of HIV prevalence estimates in low-resource settings. In younger women, prevalence approximates incidence. Sexual behavior monitoring to explain HIV distribution and trends is seldom attempted in ANC surveys. We explore the use of marital history in ANC surveillance as a proxy for sexual behavior. METHODS: Five ANC clinics in a rural African district participated in surveillance from 1999 to 2004. Unlinked anonymous HIV testing and marital history interviews (including age at first sex and socioeconomic variables) were conducted. Data on women aged <25 years were analyzed. RESULTS: Inferred sexual exposure before marriage and after first marriage increased the adjusted odds of infection with HIV by more than 0.1 for each year of exposure. Increasing years within a first marriage did not increase HIV risk. After adjusting for age, women in more recent birth cohorts were less likely to be infected. CONCLUSIONS: Marital status is useful behavioral information and can be collected in ANC surveys. Exposure in an ongoing first marriage did not increase the odds of infection with HIV in this age group. HIV prevalence decreased over time in young women. ANC surveillance programs should develop proxy sexual behavior questions, particularly in younger women

    Conducting Unlinked Anonymous HIV Surveillance in Developing Countries: Ethical, Epidemiological, and Public Health Concerns

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    Stuart Rennie and colleagues argue that while unlinked anonymous HIV testing is valuable and ethical, such surveillance can be conducted in ethically questionable ways in certain circumstances

    Octopus: A Secure and Anonymous DHT Lookup

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    Distributed Hash Table (DHT) lookup is a core technique in structured peer-to-peer (P2P) networks. Its decentralized nature introduces security and privacy vulnerabilities for applications built on top of them; we thus set out to design a lookup mechanism achieving both security and anonymity, heretofore an open problem. We present Octopus, a novel DHT lookup which provides strong guarantees for both security and anonymity. Octopus uses attacker identification mechanisms to discover and remove malicious nodes, severely limiting an adversary's ability to carry out active attacks, and splits lookup queries over separate anonymous paths and introduces dummy queries to achieve high levels of anonymity. We analyze the security of Octopus by developing an event-based simulator to show that the attacker discovery mechanisms can rapidly identify malicious nodes with low error rate. We calculate the anonymity of Octopus using probabilistic modeling and show that Octopus can achieve near-optimal anonymity. We evaluate Octopus's efficiency on Planetlab with 207 nodes and show that Octopus has reasonable lookup latency and manageable communication overhead

    From Anonymity to Identification

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    This article examines whether anonymity online has a future. In the early days of the Internet, strong cryptography, anonymous remailers, and a relative lack of surveillance created an environment conducive to anonymous communication. Today, the outlook for online anonymity is poor. Several forces combine against it: ideologies that hold that anonymity is dangerous, or that identifying evil-doers is more important than ensuring a safe mechanism for unpopular speech; the profitability of identification in commerce; government surveillance; the influence of intellectual property interests and in requiring hardware and other tools that enforce identification; and the law at both national and supranational levels. As a result of these forces, online anonymity is now much more difficult than previously, and looks to become less and less possible. Nevertheless, the ability to speak truly freely remains an important \u27safety valve\u27 technology for the oppressed, for dissidents, and for whistle-blowers. The article argues that as data collection online merges with data collection offline, the ability to speak anonymously online will only become more valuable. Technical changes will be required if online anonymity is to remain possible. Whether these changes are possible depends on whether the public comes to appreciate value the option of anonymous speech while it is still possible to engineer mechanisms to permit it

    From Anonymity to Identification

    Get PDF
    This article examines whether anonymity online has a future. In the early days of the Internet, strong cryptography, anonymous remailers, and a relative lack of surveillance created an environment conducive to anonymous communication. Today, the outlook for online anonymity is poor. Several forces combine against it: ideologies that hold that anonymity is dangerous, or that identifying evil-doers is more important than ensuring a safe mechanism for unpopular speech; the profitability of identification in commerce; government surveillance; the influence of intellectual property interests and in requiring hardware and other tools that enforce identification; and the law at both national and supranational levels. As a result of these forces, online anonymity is now much more difficult than previously, and looks to become less and less possible. Nevertheless, the ability to speak truly freely remains an important \u27safety valve\u27 technology for the oppressed, for dissidents, and for whistle-blowers. The article argues that as data collection online merges with data collection offline, the ability to speak anonymously online will only become more valuable. Technical changes will be required if online anonymity is to remain possible. Whether these changes are possible depends on whether the public comes to appreciate value the option of anonymous speech while it is still possible to engineer mechanisms to permit it
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