arXiv subjects

James Shook

Publications and source records attributed to James Shook.

4 recordsLinked to original sources

arXiv2019

A Taxonomic Approach to Understanding Emerging Blockchain Identity Management Systems

Identity management systems (IDMSs) are widely used to provision user identities while managing authentication, authorization, and data sharing within organizations and on the web. Traditional identity systems typically suffer from single points of failure, lack of interoperability, and privacy issues, such as enabling mass data collection and user tracking. Blockchain technology has the potential to alleviate these concerns: it can support the ability for users to control the custody of their own identifiers and credentials, enabling novel data ownership and governance models with built-in control and consent mechanisms. Hence, blockchain-based IDMSs, which could benefit both users and businesses, are beginning to proliferate. This work categorizes these systems into a taxonomy based on differences in blockchain architectures, governance models, and other salient features. Context is provided for the taxonomy through the description of related terms, emerging standards, and use cases while highlighting relevant security and privacy considerations.

cs.CR↗

arXiv2019

Smart Contract Federated Identity Management without Third Party Authentication Services

Federated identity management enables users to access multiple systems using a single login credential. However, to achieve this a complex privacy compromising authentication has to occur between the user, relying party (RP) (e.g., a business), and a credential service provider (CSP) that performs the authentication. In this work, we use a smart contract on a blockchain to enable an architecture where authentication no longer involves the CSP. Authentication is performed solely through user to RP communications (eliminating fees and enhancing privacy). No third party needs to be contacted, not even the smart contract. No public key infrastructure (PKI) needs to be maintained. And no revocation lists need to be checked. In contrast to competing smart contract approaches, ours is hierarchically managed (like a PKI) enabling better validation of attribute providers and making it more useful for large entities to provide identity services for their constituents (e.g., a government) while still enabling users to maintain a level of self-sovereignty.

cs.CR↗

arXiv2019

Cryptocurrency Smart Contracts for Distributed Consensus of Public Randomness

Most modern electronic devices can produce a random number. However, it is difficult to see how a group of mutually distrusting entities can have confidence in any such hardware-produced stream of random numbers, since the producer could control the output to their gain. In this work, we use public and immutable cryptocurrency smart contracts, along with a set of potentially malicious randomness providers, to produce a trustworthy stream of timestamped public random numbers. Our contract eliminates the ability of a producer to predict or control the generated random numbers, including the stored history of random numbers. We consider and mitigate the threat of collusion between the randomness providers and miners in a second, more complex contract.

cs.CR↗

arXiv2012

Threshold Digraphs

A digraph whose degree sequence has a unique vertex labeled realization is called threshold. In this paper we present several characterizations of threshold digraphs and their degree sequences, and show these characterizations to be equivalent. One of the characterizations is new, and allows for a shorter proof of the equivalence of the two known characterizations as well as proving the final characterization which appears without proof in the literature. Using this result, we obtain a new, short proof of the Fulkerson-Chen theorem on degree sequences of general digraphs.

math.CO↗