Real-time, online-editing web apps provide free and convenient services for collaboratively editing, sharing and storing files. The benefits of these web applications do not come for free: not only do service providers have full access to the users' files, but they also control access, transmission, and storage mechanisms for them. As a result, user data may be at risk of data mining, third-party interception, or even manipulation. To combat this, we propose a new system for helping to preserve the privacy of user data within collaborative environments. There are several distinct challenges in producing such a system, including developing an encryption mechanism that does not interfere with the back-end (and often proprietary) control mechanisms utilized by the service, and identifying transparent code hooks through which to obfuscate user data. Toward the first challenge, we develop a character-level encryption scheme that is more resilient to the types of attacks that plague classical substitution ciphers. For the second challenge, we design a browser extension that robustly demonstrates the feasibility of our approach, and show a concrete implementation for Google Chrome and the widely-used Google Docs platform. Our example tangibly demonstrates how several users with a shared key can collaboratively and transparently edit a Google Docs document without revealing the plaintext directly to Google.
Another closely related work is MessageGuard @cite_1 , which implements a system that layers end-to-end encryption on top of existing web applications, using the browser as a global control point and deploying as either a browser extension or a bookmarklet. Our approach differs from MessageGuard in the following ways.
@cite_1
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Developing secure software is inherently difficult, and is further hampered by a rush to market, the lack of cybersecurity-trained architects and developers, and the difficulty of identifying flaws and deploying mitigations. To address these problems, we advocate for an alternative paradigm–layering security onto applications from global control points, such as the browser, operating system, or network. This approach adds security to existing applications, relieving developers of this burden. The benefits of this paradigm are three-fold–(1) increased correctness in the implementation of security features, (2) coverage for all software, even non-maintained legacy software, and (3) more rapid and consistent deployment of threat mitigations and new security features. To demonstrate these benefits, we describe three concrete instantiations of this paradigm– MessageGuard, a system that layers end-to-end encryption in the browser; TrustBase, a system that layers authentication in the operating system; and software-defined perimeter, which layers access control at network middleboxes. In much of the theoretical literature on wireless algorithms, issues of message dissemination are considered together with issues of contention management. This combination leads to complicated algorithms and analysis, and makes it difficult to extend the work to harder communication problems. In this paper, we present results of a current project aimed at simplifying such algorithms and analysis by decomposing the treatment into two levels, using abstract "MAC layer" specifications to encapsulate the contention management. We use two different abstract MAC layers: the basic one of [14, 15] and a new probabilistic layer. We first present a typical randomized contention-manageent algorithm for a standard graph-based radio network model We show that it implements both abstract MAC layers. We combine this algorithm with greedy algorithms for single-message and multi-message global broadcast and analyze the combination, using both abstract MAC layers as intermediate layers. Using the basic MAC layer, we prove a bound of O(D log(n ∈) log Δ) for the time to deliver a single message everywhere with probability 1 -- ∈, where D is the network diameter, n is the number of nodes, and Δ is the maximum node degree. Using the probabilistic layer, we prove a bound of O((D + log(n ∈)) log Δ), which matches the best previously-known bound for single-message broadcast over the physical network model. For multi-message broadcast, we obtain bounds of O((D + kΔ) log(n ∈) log Δ) using the basic layer and O((D + kΔ log(n ∈)) log Δ) using the probabilistic layer, for the time to deliver a message everywhere in the presence of at most k concurrent messages. Recent web-based applications offer users free service in exchange for access to personal communication, such as on-line email services and instant messaging. The inspection and retention of user communication is generally intended to enable targeted marketing. However, unless specifically stated otherwise by the collecting service's privacy policy, such records have an indefinite lifetime and may be later used or sold without restriction. In this paper, we show that it is possible to protect a user's privacy from these risks by exploiting mutually oblivious, competing communication channels. We create virtual channels over online services (e.g., Google's Gmail, Microsoft's Hotmail) through which messages and cryptographic keys are delivered. The message recipient uses a shared secret to identify the shares and ultimately recover the original plaintext. In so doing, we create a wired “spread-spectrum” mechanism for protecting the privacy of web-based communication. We discuss the design and implementation of our open-source Java applet, Aquinas, and consider ways that the myriad of communication channels present on the Internet can be exploited to preserve privacy. This paper presents P3S, a publish-subscribe middleware designed to protect the privacy of subscriber interest and confidentiality of published content. P3S combines recent advances in cryptography, specifically Ciphertext Policy Attribute Based Encryption (CP-ABE) and Predicate Based Encryption (PBE) with an innovative architecture to achieve the desired level of privacy. An initial P3S prototype has been implemented on top of a COTS JMS platform (ActiveMQ). Results of preliminary security analysis and initial evaluation of latency and throughput indicate that the P3S design is both practical and flexible to provide different levels of privacy for publish-subscribe messaging over various message sizes and network bandwidth settings.