A UNIQUE ASSISTANCE THAT PROVIDES GUARANTEE THE HIDING OF DATA

The fundamental dependence on the services is to be sure the confidentiality from the data. This paper, the very first time, proposes a privacy-preserving cipher text multi-discussing mechanism to offer the above qualities. By utilizing some traditional PKE, Identity-Based File encryption (IBE), or Attribute-Based File encryption (ABE), the confidentiality from the record could be protected effectively. It combines the merits of proxy re-file encryption with anonymous technique where a cipher text could be safely and conditionally shared multiple occasions without dripping both understanding of underlying message and also the identity information of cipher text senders/recipients. The necessity of secure big data storage services are more inviting than ever before up to now. The safety type of MH-IBCPRE may be the fundamental one, where a challenger plays the sport using the foe to produce Selected-Cipher text Attacks (CCA) towards the original cipher text and re-encrypted cipher text to be able to solve a tough problem. However, the anonymity from the service clients, probably the most essential facets of privacy, should be thought about concurrently. In addition, this paper implies that the brand new primitive is safe against selected-cipher text attacks within the standard model. Furthermore, the service should also provide practical and fine-grained encrypted data discussing so that an information owner is permitted to talk about a cipher text of information amongst others under some specified conditions

Hyp3rArmor: reducing web application exposure to automated attacks

Web applications (webapps) are subjected constantly to automated, opportunistic attacks from autonomous robots (bots) engaged in reconnaissance to discover victims that may be vulnerable to specific exploits. This is a typical behavior found in botnet recruitment, worm propagation, largescale fingerprinting and vulnerability scanners. Most anti-bot techniques are deployed at the application layer, thus leaving the network stack of the webapp’s server exposed. In this paper we present a mechanism called Hyp3rArmor, that addresses this vulnerability by minimizing the webapp’s attack surface exposed to automated opportunistic attackers, for JavaScriptenabled web browser clients. Our solution uses port knocking to eliminate the webapp’s visible network footprint. Clients of the webapp are directed to a visible static web server to obtain JavaScript that authenticates the client to the webapp server (using port knocking) before making any requests to the webapp. Our implementation of Hyp3rArmor, which is compatible with all webapp architectures, has been deployed and used to defend single and multi-page websites on the Internet for 114 days. During this time period the static web server observed 964 attempted attacks that were deflected from the webapp, which was only accessed by authenticated clients. Our evaluation shows that in most cases client-side overheads were negligible and that server-side overheads were minimal. Hyp3rArmor is ideal for critical systems and legacy applications that must be accessible on the Internet. Additionally Hyp3rArmor is composable with other security tools, adding an additional layer to a defense in depth approach.This work has been supported by the National Science Foundation (NSF) awards #1430145, #1414119, and #1012798

A Deep Dive into Technical Encryption Concepts to Better Understand Cybersecurity & Data Privacy Legal & Policy Issues

Lawyers wishing to exercise a meaningful degree of leadership at the intersection of technology and the law could benefit greatly from a deep understanding of the use and application of encryption, considering it arises in so many legal scenarios. For example, in FTC v. Wyndham1 the defendant failed to implement nearly every conceivable cybersecurity control, including lack of encryption for stored data, resulting in multiple data breaches and a consequent FTC enforcement action for unfair and deceptive practices. Other examples of legal issues requiring use of encryption and other technology concepts include compliance with security requirements of GLBA & HIPAA, encryption safe harbors relative to state data breach notification laws and the CCPA, the NYDFS Cybersecurity Regulation, and PCI standards. Further, some policy discussions have taken place in 2020 regarding encrypted DNS over HTTPS, and lawyers would certainly seem to benefit from a better understanding of relevant encryption concepts to assess the privacy effectiveness of emerging encryption technologies, such as encrypted DNS. Finally, the need for technology education for lawyers is evidenced by North Carolina and Florida requiring one or more hours in technology CLE and New York in 2020 moving toward required CLE in the area of cybersecurity specifically. This article observes that there is a continuing desire for strong encryption mechanisms to advance the privacy interests of civilians’ online activities/communications (e.g., messages or web browsing). Law enforcement advocates for a “front door,” requiring tech platforms to maintain a decryption mechanism for online data, which they must produce upon the government providing a warrant. However, privacy advocates may encourage warrant-proof encryption mechanisms where tech platforms remove their ability to ever decrypt. This extreme pro-privacy position could be supported based on viewing privacy interests under a lens such as Blackstone’s ratio. Just as the Blackstone ratio principle favors constitutional protections that allow ten guilty people to go free rather than allowing one innocent person suffer, individual privacy rights could arguably favor fairly unsurveillable encrypted communications at the risk of not detecting various criminal activity. However, given that the internet can support large-scale good or evil activity, law enforcement continues to express a desire for a front door required by legislation and subject to suitable privacy safeguards, striking a balance between strong privacy versus law enforcement’s need to investigate serious crimes. In the last few decades, law enforcement appears to have lost the debate for various reasons, but the debate will likely continue for years to come. For attorneys to exercise meaningful leadership in evaluating the strength of encryption technologies relative to privacy rights, attorneys must generally understand encryption principles, how these principles are applied to data at rest (e.g., local encryption), and how they operate with respect to data in transit. Therefore, this article first explores encryption concepts primarily with regard to data at rest and then with regard to data in transit, exploring some general networking protocols as context for understanding how encryption can applied to data in transit, protecting the data payload of a packet and/or the routing/header information (i.e., the “from” and “to” field) of the packet. Part 1 of this article briefly explores the need for lawyers to understand encryption. Part 2 provides a mostly technical discussion of encryption concepts, with some legal concepts injected therein. Finally, Part 3 provides some high level legal discussion relevant to encryption (including arguments for and against law enforcement’s desire for a front door). To facilitate understanding for a non-technical legal audience, I include a variety of physical world analogies throughout (e.g., postal analogies and the like)

End-to-end security in active networks

Active network solutions have been proposed to many of the problems caused by the increasing heterogeneity of the Internet. These ystems allow nodes within the network to process data passing through in several ways. Allowing code from various sources to run on routers introduces numerous security concerns that have been addressed by research into safe languages, restricted execution environments, and other related areas. But little attention has been paid to an even more critical question: the effect on end-to-end security of active flow manipulation. This thesis first examines the threat model implicit in active networks. It develops a framework of security protocols in use at various layers of the networking stack, and their utility to multimedia transport and flow processing, and asks if it is reasonable to give active routers access to the plaintext of these flows. After considering the various security problem introduced, such as vulnerability to attacks on intermediaries or coercion, it concludes not. We then ask if active network systems can be built that maintain end-to-end security without seriously degrading the functionality they provide. We describe the design and analysis of three such protocols: a distributed packet filtering system that can be used to adjust multimedia bandwidth requirements and defend against denial-of-service attacks; an efficient composition of link and transport-layer reliability mechanisms that increases the performance of TCP over lossy wireless links; and a distributed watermarking servicethat can efficiently deliver media flows marked with the identity of their recipients. In all three cases, similar functionality is provided to designs that do not maintain end-to-end security. Finally, we reconsider traditional end-to-end arguments in both networking and security, and show that they have continuing importance for Internet design. Our watermarking work adds the concept of splitting trust throughout a network to that model; we suggest further applications of this idea

SECURE, POLICY-BASED, MULTI-RECIPIENT DATA SHARING

In distributed systems users often need to share sensitive data with other users based on the latter's ability to satisfy various policies. In many cases the data owner may not even know the identities of the data recipients, but deems it crucial that they are legitimate; i.e., satisfy the policy. Enabling such data sharing over the Internet faces the challenge of (1) securely associating access policies with data and enforcing them, and (2) protecting data as it traverses untrusted proxies and intermediate repositories. Furthermore, it is desirable to achieve properties such as: (1) flexibility of access policies; (2) privacy of sensitive access policies; (3) minimal reliance on trusted third parties; and (4) efficiency of access policy enforcement. Often schemes enabling controlled data sharing need to trade one property for another. In this dissertation, we propose two complimentary policy-based data sharing schemes that achieve different subsets of the above desired properties. In the first part of this dissertation, we focus on CiphertextPolicy Attribute- Based Encryption (CP-ABE) schemes that specify and enforce access policies cryptographically and eliminate trusted mediators. We motivate the need for flexible attribute organization within user keys for efficient support of many practical applications. We then propose Ciphertext-Policy Attribute-Set Based Encryption (CP-ASBE) which is the first CP-ABE scheme to (1) efficiently support naturally occurring compound attributes, (2) support multiple numerical assignments for a given attribute in a single key and (3) provide efficient key management. While the CP-ASBE scheme minimizes reliance on trusted mediators, it can support neither context-based policies nor policy privacy. In the second part of this dissertation, we propose Policy Based Encryption System (PBES), which employs mediated decryption and supports both context-based policies and policy privacy. Finally, we integrate the proposed schemes into practical applications (i.e., CP-ASBE scheme with Attribute-Based Messaging (ABM) and PBES scheme with a conditional data sharing application in the Power Grid) and demonstrate their usefulness in practice

IST Austria Thesis

Many security definitions come in two flavors: a stronger “adaptive” flavor, where the adversary can arbitrarily make various choices during the course of the attack, and a weaker “selective” flavor where the adversary must commit to some or all of their choices a-priori. For example, in the context of identity-based encryption, selective security requires the adversary to decide on the identity of the attacked party at the very beginning of the game whereas adaptive security allows the attacker to first see the master public key and some secret keys before making this choice. Often, it appears to be much easier to achieve selective security than it is to achieve adaptive security. A series of several recent works shows how to cleverly achieve adaptive security in several such scenarios including generalized selective decryption [Pan07][FJP15], constrained PRFs [FKPR14], and Yao’s garbled circuits [JW16]. Although the above works expressed vague intuition that they share a common technique, the connection was never made precise. In this work we present a new framework (published at Crypto ’17 [JKK+17a]) that connects all of these works and allows us to present them in a unified and simplified fashion. Having the framework in place, we show how to achieve adaptive security for proxy re-encryption schemes (published at PKC ’19 [FKKP19]) and provide the first adaptive security proofs for continuous group key agreement protocols (published at S&P ’21 [KPW+21]). Questioning optimality of our framework, we then show that currently used proof techniques cannot lead to significantly better security guarantees for "graph-building" games (published at TCC ’21 [KKPW21a]). These games cover generalized selective decryption, as well as the security of prominent constructions for constrained PRFs, continuous group key agreement, and proxy re-encryption. Finally, we revisit the adaptive security of Yao’s garbled circuits and extend the analysis of Jafargholi and Wichs in two directions: While they prove adaptive security only for a modified construction with increased online complexity, we provide the first positive results for the original construction by Yao (published at TCC ’21 [KKP21a]). On the negative side, we prove that the results of Jafargholi and Wichs are essentially optimal by showing that no black-box reduction can provide a significantly better security bound (published at Crypto ’21 [KKPW21c])

CPA\u27s guide to information security

https://egrove.olemiss.edu/aicpa_guides/1963/thumbnail.jp

A Taxonomy for and Analysis of Anonymous Communications Networks

Any entity operating in cyberspace is susceptible to debilitating attacks. With cyber attacks intended to gather intelligence and disrupt communications rapidly replacing the threat of conventional and nuclear attacks, a new age of warfare is at hand. In 2003, the United States acknowledged that the speed and anonymity of cyber attacks makes distinguishing among the actions of terrorists, criminals, and nation states difficult. Even President Obama’s Cybersecurity Chief-elect recognizes the challenge of increasingly sophisticated cyber attacks. Now through April 2009, the White House is reviewing federal cyber initiatives to protect US citizen privacy rights. Indeed, the rising quantity and ubiquity of new surveillance technologies in cyberspace enables instant, undetectable, and unsolicited information collection about entities. Hence, anonymity and privacy are becoming increasingly important issues. Anonymization enables entities to protect their data and systems from a diverse set of cyber attacks and preserves privacy. This research provides a systematic analysis of anonymity degradation, preservation and elimination in cyberspace to enhance the security of information assets. This includes discovery/obfuscation of identities and actions of/from potential adversaries. First, novel taxonomies are developed for classifying and comparing well-established anonymous networking protocols. These expand the classical definition of anonymity and capture the peer-to-peer and mobile ad hoc anonymous protocol family relationships. Second, a unique synthesis of state-of-the-art anonymity metrics is provided. This significantly aids an entity’s ability to reliably measure changing anonymity levels; thereby, increasing their ability to defend against cyber attacks. Finally, a novel epistemic-based mathematical model is created to characterize how an adversary reasons with knowledge to degrade anonymity. This offers multiple anonymity property representations and well-defined logical proofs to ensure the accuracy and correctness of current and future anonymous network protocol design