UPPRESSO: Untraceable and Unlinkable Privacy-PREserving Single Sign-On Services

Single sign-on (SSO) allows a user to maintain only the credential at the identity provider (IdP), to login to numerous RPs. However, SSO introduces extra privacy threats, compared with traditional authentication mechanisms, as (a) the IdP could track all RPs which a user is visiting, and (b) collusive RPs could learn a user's online profile by linking his identities across these RPs. This paper proposes a privacypreserving SSO system, called UPPRESSO, to protect a user's login activities against both the curious IdP and collusive RPs. We analyze the identity dilemma between the security requirements and these privacy concerns, and convert the SSO privacy problems into an identity transformation challenge. In each login instance, an ephemeral pseudo-identity (denoted as PID_RP ) of the RP, is firstly negotiated between the user and the RP. PID_RP is sent to the IdP and designated in the identity token, so the IdP is not aware of the visited RP. Meanwhile, PID_RP is used by the IdP to transform the permanent user identity ID_U into an ephemeral user pseudo-identity (denoted as PID_U ) in the identity token. On receiving the identity token, the RP transforms PID_U into a permanent account (denoted as Acct) of the user, by an ephemeral trapdoor in the negotiation. Given a user, the account at each RP is unique and different from ID_U, so collusive RPs cannot link his identities across these RPs. We build the UPPRESSO prototype on top of MITREid Connect, an open-source implementation of OIDC. The extensive evaluation shows that UPPRESSO fulfills the requirements of both security and privacy and introduces reasonable overheads

Epidemiology, Quality and Reporting Characteristics of Systematic Reviews of Traditional Chinese Medicine Interventions Published in Chinese Journals

Systematic reviews (SRs) of TCM have become increasingly popular in China and have been published in large numbers. This review provides the first examination of epidemiological characteristics of these SRs as well as compliance with the PRISMA and AMSTAR guidelines.To examine epidemiological and reporting characteristics as well as methodological quality of SRs of TCM published in Chinese journals.Four Chinese databases were searched (CBM, CSJD, CJFD and Wanfang Database) for SRs of TCM, from inception through Dec 2009. Data were extracted into Excel spreadsheets. The PRISMA and AMSTAR checklists were used to assess reporting characteristics and methodological quality, respectively.A total of 369 SRs were identified, most (97.6%) of which used the terms systematic review or meta-analysis in the title. None of the reviews had been updated. Half (49.8%) were written by clinicians and nearly half (47.7%) were reported in specialty journals. The impact factors of 45.8% of the journals published in were zero. The most commonly treated conditions were diseases of the circulatory and digestive disease. Funding sources were not reported for any reviews. Most (68.8%) reported information about quality assessment, while less than half (43.6%) reported assessing for publication bias. Statistical mistakes appeared in one-third (29.3%) of reviews and most (91.9%) did not report on conflict of interest.While many SRs of TCM interventions have been published in Chinese journals, the quality of these reviews is troubling. As a potential key source of information for clinicians and researchers, not only were many of these reviews incomplete, some contained mistakes or were misleading. Focusing on improving the quality of SRs of TCM, rather than continuing to publish them in great quantity, is urgently needed in order to increase the value of these studies

Cholelithiasis, cholecystectomy and risk of hepatocellular carcinoma: A meta-analysis

Available evidence of the relationship between cholelithiasis, cholecystectomy, and risk of liver cancer and hence we conducted a meta-analysis to investigate the relationships. PubMed, EMBASE, and ISI Web of Knowledge were searched to identify all published cohort studies and case-control studies that evaluated the relationships of cholelithiasis, cholecystectomy and risk of liver cancer and single-cohort studies which evaluated the incidence of liver cancer among patients who understood cholecystectomy (up to February 2013). Comprehensive meta-analysis software was used for meta-analysis. A total of 11 observational studies (six cohort studies and five case-control studies) were included in this meta-analysis. The result from meta-analysis showed that cholecystectomy (risk ratio [RR]: 1.59, 95% confidence interval [CI]: 1.01-2.51, I2 = 72%) and cholecystolithiasis (RR: 5.40, 95% CI: 3.69-7.89, I2 = 93%) was associated with more liver cancer, especially for intrahepatic cholangiocarcinoma (ICC) (cholecystectomy: RR: 3.51, 95% CI: 1.84-6.71, I2 = 26%; cholecystolithiasis: RR: 11.06, 95% CI: 6.99-17.52, I2 = 0%). The pooled standardized incidence rates (SIR) of liver cancer in patients who understood cholecystectomy showed cholecystectomy might increase the incidence of liver cancer (SIR: 1.57, 95% CI: 1.13-2.20, I2 = 15%). Based on the results of the meta-analysis, cholecystectomy and cholecystolithiasis seemed to be involved in the development of liver cancer, especially for ICC. However, most available studies were case-control studies and short-term cohort studies, so the future studies should more long-term cohort studies should be well-conducted to evaluate the long-term relationship

LightTx: A Lightweight Transactional Design in Flash-based SSDs to Support Flexible Transactions ∗

Abstract—Flash memory has accelerated the architectural evolution of storage systems with its unique characteristics compared to magnetic disks. The no-overwrite property of flash memory has been leveraged to efficiently support transactions, a commonly used mechanism in systems to provide consistency. However, existing transaction designs embedded in flash-based Solid State Drives (SSDs) have limited support for transaction flexibility, i.e., support for different isolation levels between transactions, which is essential to enable different systems to make tradeoffs between performance and consistency. Since they provide support for only strict isolation between transactions, existing designs lead to a reduced number of on-the-fly requests and therefore cannot exploit the abundant internal parallelism of an SSD. There are two design challenges that need to be overcome to support flexible transactions: (1) enabling a transaction commi

LightTx: A Lightweight Transactional Design in Flash-based SSDs to Support Flexible Transactions

<p>Flash memory has accelerated the architectural evolution of storage systems with its unique characteristics compared to magnetic disks. The no-overwrite property of flash memory has been leveraged to efficiently support transactions, a commonly used mechanism in systems to provide consistency. However, existing transaction designs embedded in flash-based Solid State Drives (SSDs) have limited support for transaction flexibility, i.e., support for different isolation levels betweentransactions, which is essential to enable different systems to make tradeoffs between performance and consistency. Since they provide support for only strict isolation between transactions, existingdesigns lead to a reduced number of on-the-fly requests and therefore cannot exploit the abundant internal parallelism of an SSD. There are two design challenges that need to be overcome to supportflexible transactions: (1) enabling a transaction commit protocol that supports parallel execution oftransactions; and (2) efficiently tracking the state of transactions that have pages scattered over different locations due to parallel allocation of pages. In this paper, we propose LightTx to address these two challenges. LightTx supports transaction flexibility using a lightweight embedded transactiondesign. The design of LightTx is based on two key techniques. First, LightTx uses a commit protocol that determines the transaction state solely inside each transaction (as opposed to having dependencies between transactions that complicate state tracking) in order to support paralleltransaction execution. Second, LightTx periodically retires the dead transactions to reduce transactionstate tracking cost. Experiments show that LightTx provides up to 20.6% performance improvement due to transaction flexibility. LightTx also achieves nearly the lowest overhead in garbage collection and mapping persistence compared to existing embedded transaction designs.</p