Public Key Infrastructure based on Authentication of Media Attestments

Many users would prefer the privacy of end-to-end encryption in their online communications if it can be done without significant inconvenience. However, because existing key distribution methods cannot be fully trusted enough for automatic use, key management has remained a user problem. We propose a fundamentally new approach to the key distribution problem by empowering end-users with the capacity to independently verify the authenticity of public keys using an additional media attestment. This permits client software to automatically lookup public keys from a keyserver without trusting the keyserver, because any attempted MITM attacks can be detected by end-users. Thus, our protocol is designed to enable a new breed of messaging clients with true end-to-end encryption built in, without the hassle of requiring users to manually manage the public keys, that is verifiably secure against MITM attacks, and does not require trusting any third parties

Privacy, security, and trust issues in smart environments

Recent advances in networking, handheld computing and sensor technologies have driven forward research towards the realisation of Mark Weiser's dream of calm and ubiquitous computing (variously called pervasive computing, ambient computing, active spaces, the disappearing computer or context-aware computing). In turn, this has led to the emergence of smart environments as one significant facet of research in this domain. A smart environment, or space, is a region of the real world that is extensively equipped with sensors, actuators and computing components [1]. In effect the smart space becomes a part of a larger information system: with all actions within the space potentially affecting the underlying computer applications, which may themselves affect the space through the actuators. Such smart environments have tremendous potential within many application areas to improve the utility of a space. Consider the potential offered by a smart environment that prolongs the time an elderly or infirm person can live an independent life or the potential offered by a smart environment that supports vicarious learning

Merging and Extending the PGP and PEM Trust Models - the ICE-TEL Trust Model

The ICE-TEL project is a pan-European project that is building an Internet X.509 based certification infrastructure throughout Europe, plus several secure applications that will use it. This paper describes the trust model that is being implemented by the project. A trust model specifies the means by which a user may build trust in the assertion that a remote user is really who he purports to be (authentication) and that he does in fact have a right to access the service or information that he is requesting (authorization). The ICE-TEL trust model is based on a merging of and extensions to the existing Pretty Good Privacy (PGP) web of trust and Privacy Enhanced Mail (PEM) hierarchy of trust models, and is called a web of hierarchies trust model. The web of hierarchies model has significant advantages over both of the previous models, and these are highlighted here. The paper further describes the way that the trust model is enforced through some of the new extensions in the X.509 V3 certificates, and gives examples of its use in different scenarios

Security functions for a file repository

When personal machines are incorporated into distributed\ud systems a new mixture of threats is exposed.\ud The security effort in the MobyDick project\ud is aimed at understanding how privacy can be protected\ud in this new environment. Our claim is that\ud a two-step process for authentication and authorisation\ud is required, but also sufficient. The research\ud vehicle is a distributed file repository

Local and Global Trust Based on the Concept of Promises

We use the notion of a promise to define local trust between agents possessing autonomous decision-making. An agent is trustworthy if it is expected that it will keep a promise. This definition satisfies most commonplace meanings of trust. Reputation is then an estimation of this expectation value that is passed on from agent to agent. Our definition distinguishes types of trust, for different behaviours, and decouples the concept of agent reliability from the behaviour on which the judgement is based. We show, however, that trust is fundamentally heuristic, as it provides insufficient information for agents to make a rational judgement. A global trustworthiness, or community trust can be defined by a proportional, self-consistent voting process, as a weighted eigenvector-centrality function of the promise theoretical graph

Building Trust Networks

The common agreement in the industry is that the Public Key Infrastructure is complex and expensive. From the year 1976 with the introduction of public key cryptography and the introduction of PKI concept in 1977 a lot of scientific resources has been spent on creation of usable key exchange systems and concepts to build trust networks. Most EU Member States have implemented their own national Public Key Infrastructure solutions mainly to enable strong authentication of citizens. They are however not the only systems within the EU to utilize PKI. Due to the nature of the PKI it is most convenient or suitable in an environment with stakeholders with similar agendas. This has resulted in several new PKI developments for specific purposes, within one industry or one vertical such as healthcare. Some Member States have tried to incorporate vertical needs with an all-purpose PKI solution, such as the Austrian eID card with so called sector specific certificates (http://ec.europa.eu/idabc/en/document/4486/5584). From the CIA (Confidentiality, Integrity, Availability) triangle public key cryptography provides confidentiality and integrity. The modern world however has more requirements in environments where sensitive information is being exchanged. It is not enough to know identity of the entity trying to access the information, but to also know the entity permissions or privileges regarding the requested resource. The authorization process grants the user specific permissions to e.g. access, modify or delete resources. A pure PKI does not allow us to build complex authorization policies, and therefore some of the Member States have built (authentication and) authorization solutions on top of existing authentication infrastructures, especially in the eGovernment sector. The scientific community has also tried to solve this issue by creating extensions to the basic PKI concept, and some of these concepts have been successful. Another problem with large scales systems is the key distribution. Managing a large number of keys using a central solution such as PKI has proven to be problematic in certain conditions. Either there are tradeoffs in security, or problems with application support. The last issue deals with public key cryptography itself. Current cryptography relies on the fact that it provides enough security based on availability of the resources, i.e. computational power. New approaches have been introduced both scientifically and commercially by moving away from the mathematics to other areas such as quantum mechanics. This paper is a quick review on some of the existing systems and their benefits and inherent challenges as well as a short introduction to new developments in the areas of authentication, authorization and key distribution.JRC.G.6-Security technology assessmen

Anonymity in Bitcoin and Bitmessage

This report describes two projects created by the author which are based on ideas which originate from the Bitcoin community. The first, bmd, is a re-implementation of the Bitmessage protocol in go. Bitmessage is an anonymous and secure messaging system invented by Jonathan Warren, who was inspired by the design of Bitcoin's p2p network. [WARR1] The second is Shufflepuff, an implementation of a protocol called CoinShuffle[RUFF1] which allows several people to construct a Bitcoin transaction with an input and an output for each participant without any participant knowing who owns which output. CoinShuffle was invented by Tim Ruffing et al, and it is an upgrade of a protocol called CoinJoin, invented by Gregory Maxwell. This paper discusses the background, properties, applications, and design of bmd and Shufflepuff. There is also a report of a performance analysis on bmd.Electrical and Computer Engineerin