A Smart Contract for Boardroom Voting with Maximum Voter Privacy

We present the first implementation of a decentralised and self-tallying internet voting protocol with maximum voter privacy using the Blockchain. The Open Vote Network is suitable for boardroom elections and is written as a smart contract for Ethereum. Unlike previously proposed Blockchain e-voting protocols, this is the first implementation that does not rely on any trusted authority to compute the tally or to protect the voter’s privacy. Instead, the Open Vote Network is a self-tallying protocol, and each voter is in control of the privacy of their own vote such that it can only be breached by a full collusion involving all other voters. The execution of the protocol is enforced using the consensus mechanism that also secures the Ethereum blockchain. We tested the implementation on Ethereum’s official test network to demonstrate its feasibility. Also, we provide a financial and computational breakdown of its execution cost

Refund Attacks on Bitcoin’s Payment Protocol

BIP70 is a community-accepted Payment Protocol standard that governs how merchants and customers perform payments in Bitcoin. This standard is supported by most major wallets and the two dominant Payment Processors: Coinbase and BitPay, who collectively provide the infrastructure for accepting Bitcoin as a form of payment to more than 100,000 merchants. In this paper, we present new attacks on the Payment Protocol, which affect all BIP70 merchants. The Silkroad Trader attack highlights an authentication vulnerability in the Payment Protocol while the Marketplace Trader attack exploits the refund policies of existing Payment Processors. Both attacks have been experimentally verified on real-life merchants using a modified Bitcoin wallet. The attacks have been acknowledged by both Coinbase and Bitpay with temporary mitigation measures put in place. However, to fully address the identified issues will require revising the BIP70 standard. We present a concrete proposal to revise BIP70 by providing the merchant with publicly verifiable evidence to prevent both attacks

Authenticated Key Exchange over Bitcoin

Bitcoin is designed to protect user anonymity (or pseudonymity) in a financial transaction, and has been increasingly adopted by major e- commerce websites such as Dell, PayPal and Expedia. While the anonymity of Bitcoin transactions has been extensively studied, little attention has been paid to the security of post-transaction correspondence. In a commercial ap- plication, the merchant and the user often need to engage in follow-up corre- spondence after a Bitcoin transaction is completed, e.g., to acknowledge the receipt of payment, to confirm the billing address, to arrange the product de- livery, to discuss refund and so on. Currently, such follow-up correspondence is typically done in plaintext via email with no guarantee on confidentiality. Obviously, leakage of sensitive data from the correspondence (e.g., billing ad- dress) can trivially compromise the anonymity of Bitcoin users. In this paper, we initiate the first study on how to realise end-to-end secure communica- tion between Bitcoin users in a post-transaction scenario without requiring any trusted third party or additional authentication credentials. This is an important new area that has not been covered by any IEEE or ISO/IEC se- curity standard, as none of the existing PKI-based or password-based AKE schemes are suitable for the purpose. Instead, our idea is to leverage the Bit- coin’s append-only ledger as an additional layer of authentication between previously confirmed transactions. This naturally leads to a new category of AKE protocols that bootstrap trust entirely from the block chain. We call this new category “Bitcoin-based AKE” and present two concrete protocols: one is non-interactive with no forward secrecy, while the other is interactive with additional guarantee of forward secrecy. Finally, we present proof-of-concept prototypes for both protocols with experimental results to demonstrate their practical feasibility

On secure E-voting over blockchain

This paper discusses secure methods to conduct e-voting over a blockchain in three different settings: decentralized voting, centralized remote voting and centralized polling station voting. These settings over almost all voting scenarios that occur in practice. A proof-of-concept implementation for decentralized voting over Ethereum’s blockchain is presented. This work demonstrates the suitable use of a blockchain not just as a public bulletin board, but more importantly, as a trustworthy computing platform that enforces the correct execution of the voting protocol in a publicly verifiable manner. We also discuss scaling up a blockchain-based voting application for national elections. We show that for national-scale elections the major verifiability problems can be addressed without having to depend on any blockchain. However, a blockchain remains a viable option to realize a public bulletin board, which has the advantage of being a “preventive” measure to stop retrospective changes on previously published records as opposed to a “detective” measure like the use of mirror websites

On Secure E-Voting over Blockchain

This article discusses secure methods to conduct e-voting over a blockchain in three different settings: decentralized voting, centralized remote voting, and centralized polling station voting. These settings cover almost all voting scenarios that occur in practice. A proof-of-concept implementation for decentralized voting over Ethereum's blockchain is presented. This work demonstrates the suitable use of a blockchain not just as a public bulletin board but, more importantly, as a trustworthy computing platform that enforces the correct execution of the voting protocol in a publicly verifiable manner. We also discuss scaling up a blockchain-based voting application for national elections. We show that for national-scale elections the major verifiability problems can be addressed without having to depend on any blockchain. However, a blockchain remains a viable option to realize a public bulletin board, which has the advantage of being a "preventive"measure to stop retrospective changes on previously published records as opposed to a "detective"measure like the use of mirror websites. CCS Concepts: • Security and privacy

Examining constipation assessment and management of patients with advanced cancer receiving specialist palliative care: A multi-site retrospective case note review of clinical practice

Constipation is a common symptom for patients receiving palliative care. Whilst international clinical guidelines are available on the clinical management of constipation for people with advanced cancer receiving specialist palliative care (SPC), the extent to which the guidelines are implemented in practice is unclear. This study aimed to examine clinical practices for the assessment and management of constipation for patients with advanced cancer within inpatient SPC settings. A multi-site retrospective case-note review was conducted, consisting of 150 patient case-notes from three inpatient SPC units across the United Kingdom between August 2016 and May 2017. The variables selected for review were determined by the recommendations within the clinical guidelines. Descriptive statistics, cross tabulation, chi square, and bivariate correlations were used to examine clinical practices compared to policy guidelines for the assessment and management of constipation. Reporting was structured by the STROBE checklist for observational research (Additional File 2). A comprehensive assessment, including a full history and performing a physical exam, was recorded for 109 patients (73%), however, no standardised documentation was utilised. Assessment was nurse led, with variable involvement across sites of other members of the multidisciplinary team (MDT). Education on prevention was documented in 30 (20%) case-notes, and 53% recorded evidence of non-pharmacological intervention. Age, gender, and reason for admission did not impact on the likelihood of receiving a comprehensive assessment, education, or non-pharmacological intervention, however, significant differences were evident between sites. Pharmacological management was well developed and aligned to the guidelines however, 33% of patient case-notes recorded no information on the titration of laxatives. Twelve percent of patients experienced partial or complete bowel obstruction, and management strategies were variable. Constipation management is driven by a pharmacological approach, with little evidence of the implementation of preventative and non-pharmacological strategies. The nurse plays a key coordinating role in assessment; however, involvement and roles of the wider MDT varies. Accurate recording of care is essential when examining clinical practice and identifying areas for improvement. Further education is needed to equip HCPs with the knowledge and skills to ensure consistency in assessment and implementation of appropriate non-pharmacological/ preventative strategies

Sensor technologies for quality control in engineered tissue manufacturing

The use of engineered cells, tissues, and organs has the opportunity to change the way injuries and diseases are treated. Commercialization of these groundbreaking technologies has been limited in part by the complex and costly nature of their manufacture. Process-related variability and even small changes in the manufacturing process of a living product will impact its quality. Without real-time integrated detection, the magnitude and mechanism of that impact are largely unknown. Real-time and non-destructive sensor technologies are key for in-process insight and ensuring a consistent product throughout commercial scale-up and/or scale-out. The application of a measurement technology into a manufacturing process requires cell and tissue developers to understand the best way to apply a sensor to their process, and for sensor manufacturers to understand the design requirements and end-user needs. Furthermore, sensors to monitor component cells’ health and phenotype need to be compatible with novel integrated and automated manufacturing equipment. This review summarizes commercially relevant sensor technologies that can detect meaningful quality attributes during the manufacturing of regenerative medicine products, the gaps within each technology, and sensor considerations for manufacturing

Performance measurement for co-occurring mental health and substance use disorders

<p>Abstract</p> <p>Background</p> <p>Co-occurring mental health and substance use disorders (COD) are the norm rather than the exception. It is therefore critical that performance measures are developed to assess the quality of care for individuals with COD irrespective of whether they seek care in mental health systems or substance abuse systems or both.</p> <p>Methods</p> <p>We convened an expert panel and asked them to rate a series of structure, process, and outcomes measures for COD using a structured evaluation tool with domains for importance, usefulness, validity, and practicality.</p> <p>Results</p> <p>We chose twelve measures that demonstrated promise for future pilot testing and refinement. The criteria that we applied to select these measures included: balance across structure, process, and outcome measures, quantitative ratings from the panelists, narrative comments from the panelists, and evidence the measure had been tested in a similar form elsewhere.</p> <p>Conclusion</p> <p>To be successful performance measures need to be developed in such a way that they align with needs of administrators and providers. Policymakers need to work with all stakeholders to establish a concrete agenda for developing, piloting and implementing performance measures that include COD. Future research could begin to consider strategies that increase our ability to use administrative coding in mental health and substance use disorder systems to efficiently capture quality relevant clinical data.</p