Social network sites SNSs are increasingly attracting the attention of academic and industry researchers intrigued by their affordances and reach This special theme section of the Journal of Computer-Mediated Communication brings together scholarship on these emergent phenomena In this introductory article, we describe features of SNSs and propose a comprehensive definition We then present one perspective on the history of such sites, discussing key changes and developments After briefly summarizing existing scholarship concerning SNSs, we discuss the articles in this special section and conclude with considerations for future research

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1083-6101.2007.00393.x

Social Network Sites: Definition, History, and Scholarship

Cryptosystem designers frequently assume that secrets will be manipulated in closed, reliable computing environments. Unfortunately, actual computers and microchips leak information about the operations they process. This paper examines specific methods for analyzing power consumption measurements to find secret keys from tamper resistant devices. We also discuss approaches for building cryptosystems that can operate securely in existing hardware that leaks information.

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Differential Power Analysis

This paper describes a new replication algorithm that is able to tolerate Byzantine faults. We believe that Byzantinefault-tolerant algorithms will be increasingly important in the future because malicious attacks and software errors are increasingly common and can cause faulty nodes to exhibit arbitrary behavior. Whereas previous algorithms assumed a synchronous system or were too slow to be used in practice, the algorithm described in this paper is practical: it works in asynchronous environments like the Internet and incorporates several important optimizations that improve the response time of previous algorithms by more than an order of magnitude. We implemented a Byzantine-fault-tolerant NFS service using our algorithm and measured its performance. The results show that our service is only 3% slower than a standard unreplicated NFS.

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Practical Byzantine fault tolerance

National Institute of Standards and Technology における超伝導研究及び生活

Together with an explosive growth of the mobile applications and emerging of cloud computing concept, mobile cloud computing (MCC) has been introduced to be a potential technology for mobile services. MCC integrates the cloud computing into the mobile environment and overcomes obstacles related to the performance (e.g., battery life, storage, and bandwidth), environment (e.g., heterogeneity, scalability, and availability), and security (e.g., reliability and privacy) discussed in mobile computing. This paper gives a survey of MCC, which helps general readers have an overview of the MCC including the definition, architecture, and applications. The issues, existing solutions, and approaches are presented. In addition, the future research directions of MCC are discussed. Copyright © 2011 John Wiley & Sons, Ltd.

A survey of mobile cloud computing: architecture, applications, and approaches

Sometimes a "friendly" email message tempts recipients to reveal more online than they otherwise would, playing right into the sender's hand.

Social phishing

Cloud computing is clearly one of today's most enticing technology areas due, at least in part, to its cost-efficiency and flexibility. However, despite the surge in activity and interest, there are significant, persistent concerns about cloud computing that are impeding momentum and will eventually compromise the vision of cloud computing as a new IT procurement model. In this paper, we characterize the problems and their impact on adoption. In addition, and equally importantly, we describe how the combination of existing research thrusts has the potential to alleviate many of the concerns impeding adoption. In particular, we argue that with continued research advances in trusted computing and computation-supporting encryption, life in the cloud can be advantageous from a business intelligence standpoint over the isolated alternative that is more common today.

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Controlling data in the cloud: outsourcing computation without outsourcing control

For many proofs of knowledge it is important that only the verifier designated by the confirmer can obtain any conviction of the correctness of the proof. A good example of such a situation is for undeniable signatures, where the confirmer of a signature wants to make sure that only the intended verifier(s) in fact can be convinced about the validity or invalidity of the signature.

Generally, authentication of messages and off-the-record messages are in conflict with each other. We show how, using designation of verifiers, these notions can be combined, allowing authenticated but private conversations to take place. Our solution guarantees that only the specified verifier can be convinced by t,he proof, even if he shares all his secret information with entities that want to get convinced.

Our solution is based on trap-door conim.itments [4], allowing the designated verifier to open up commitments in any way he wants. We demonstrate how a trap-door commitment scheme can be uscd to construct designated verifier proofs, both interactive and non-interactive. We examplify the verifier designation method for the confirmation protocol for undeniable signatures.

/pdf/designated-verifier-proofs-and-their-applications-bi8hzib18j.pdf

Designated verifier proofs and their applications

We introduce a new cryptographic technique that we call universal re-encryption. A conventional cryptosystem that permits re-encryption, such as ElGamal, does so only for a player with knowledge of the public key corresponding to a given ciphertext. In contrast, universal re-encryption can be done without knowledge of public keys. We propose an asymmetric cryptosystem with universal re-encryption that is half as efficient as standard ElGamal in terms of computation and storage.

/pdf/universal-re-encryption-for-mixnets-1icf0rnwrn.pdf

Universal Re-encryption for Mixnets

The bread pudding protocol of the present invention represents a novel use of proofs of work and is based upon the same principle as the dish from which it takes its name, namely, that of reuse to minimize waste. Whereas the traditional bread pudding recipe recycles stale bread, our bread pudding protocol recycles the “stale” computations in a POW to perform a separate and useful task, while also maintaining privacy in the task. In one advantageous embodiment of our bread pudding protocol, we consider the computationally intensive operation of minting coins in the MicroMint scheme of Rivest and Shamir and demonstrate how the minting operation can be partitioned into a collection of POWs, which are then used to shift the burden of the minting operation onto a large group of untrusted computational devices. Thus, the computational effort invested in the POWs is recycled to accomplish the minting operation.

Markus Jakobsson

Papers

Social phishing

Controlling data in the cloud: outsourcing computation without outsourcing control

Designated verifier proofs and their applications

Universal Re-encryption for Mixnets

Proofs of Work and Bread Pudding Protocols