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

Greenpass Client Tools for Delegated Authorization in Wireless Networks

Dartmouth\u27s Greenpass project seeks to provide strong access control to a wireless network while simultaneously providing flexible guest access; to do so, it augments the Wi-Fi Alliance\u27s existing WPA standard, which offers sufficiently strong user authentication and access control, with authorization based on SPKI certificates. SPKI allows certain local users to delegate network access to guests by issuing certificates that state, in essence, he should get access because I said it\u27s okay. The Greenpass RADIUS server described in Kim\u27s thesis [55] performs an authorization check based on such statements so that guests can obtain network access without requiring a busy network administrator to set up new accounts in a centralized database. To our knowledge, Greenpass is the first working delegation-based solution to Wi-Fi access control. My thesis describes the Greenpass client tools, which allow a guest to introduce himself to a delegator and allow the delegator to issue a new SPKI certificate to the guest. The guest does not need custom client software to introduce himself or to connect to the Wi-Fi network. The guest and delegator communicate using a set of Web applications. The guest obtains a temporary key pair and X.509 certificate if needed, then sends his public key value to a Web server we provide. The delegator looks up her guest\u27s public key and runs a Java applet that lets her verify her guests\u27 identity using visual hashing and issue a new SPKI certificate to him. The guest\u27s new certificate chain is stored as an HTTP cookie to enable him to push it to an authorization server at a later time. I also describe how Greenpass can be extended to control access to a virtual private network (VPN) and suggest several interesting future research and development directions that could build on this work.My thesis describes the Greenpass client tools, which allow a guest to introduce himself to a delegator and allow the delegator to issue a new SPKI certificate to the guest. The guest does not need custom client software to introduce himself or to connect to the Wi-Fi network. The guest and delegator communicate using a set of Web applications. The guest obtains a temporary key pair and X.509 certificate if needed, then sends his public key value to a Web server we provide. The delegator looks up her guest\u27s public key and runs a Java applet that lets her verify her guests\u27 identity using visual hashing and issue a new SPKI certificate to him. The guest\u27s new certificate chain is stored as an HTTP cookie to enable him to push it to an authorization server at a later time. I also describe how Greenpass can be extended to control access to a virtual private network (VPN) and suggest several interesting future research and development directions that could build on this work

Secure Hardware Enhanced MyProxy: A Ph.D. Thesis Proposal

In 1976, Whitfield Diffie and Martin Hellman demonstrated how New Directions In Cryptography could enable secure information exchange between parties that do not share secrets. In order for public key cryptography to work in modern distributed environments, we need an infrastructure for finding and trusting other parties\u27 public keys (i.e., a PKI). A number of useful applications become possible with PKI. While the applications differ in how they use keys (e.g., S/MIME uses the key for message encryption and signing, while client-side SSL uses the key for authentication), all applications share one assumption: users have keypairs. In previous work, we examined the security aspects of some of the standard keystores and the their interaction with the OS. We concluded that desktops are not safe places to store private keys, and we demonstrated the permeability of keystores such as the default Microsoft keystore and the Mozilla keystore. In addition to being unsafe, these desktop keystores have the added disadvantage of being immobile. In other previous work, we examined trusted computing. In industry, a new trusted computing initiative has emerged: the Trusted Computing Platform Alliance (TCPA) (now renamed the Trusted Computing Group (TCG)). The goal of the TCG design is lower-assurance security that protects an entire desktop platform and is cheap enough to be commercially feasible. Last year, we built a trusted computing platform based on the TCG specifications and hardware. The picture painted by these previous projects suggests that common desktops are not secure enough for use as PKI clients, and trusted computing can improve the security of client machines. The question that I propose to investigate is: Can I build a system which applies trusted computing hardware in a reasonable manner in order to make desktops usable for PKI? My design begins with the Grid community\u27s MyProxy credential repository, and enhances it to take advantage of secure hardware on the clients, at the repository, and in the policy framework. The result is called Secure Hardware Enhanced MyProxy

Technologies to Support Authentication in Higher Education:A Study for the UK Joint Information Systems Committee, August 21th, 1996

This report provides a short and limited study, commissioned by JISC, of the technologies available to support authentication, reviews the needs expressed by a set of people contacted for the study, and provides the beginnings of a road-map on how a National system might be established.First a brief overview of the fundamentals of Security technology is provided. As part of the study, we were asked to consult a number of people - particularly from the set of those supported under the JISC Electronic Library initiative. These were supplemented by some people at UKERNA and in Information Services departments in the universities. We present our impressions of the requirements envisioned by the people consulted, and their proposed solutions; with very few exceptions, the needs expressed were very limited, and the solutions limited to specific applications. This reflects, we believe, more the selection of the people consulted, than the true needs of the area. It was also coloured, in our view, by the fact that there was no indication that any finance for a wider initiative might be available.A more detailed review of the current methods of authentication, the needs and the status of different applications follows. This includes a brief discussion about the Standards being developed in the Internet Engineering Task Force in conjunction with the wider deployment of the Internet and the status of infrastructure standardisation and deployment. We consider also a number of applications: electronic mail, the World Wide Web, remote log-in, document security, multimedia conferencing, directories, general network facilities and electronic commerce. A brief discussion of a number of ancillary technical and legal issues follow: this includes smart-cards, directory systems and key escrow. The existence of legal considerations is indicated, but little argument is developed other than the appending of proposed Government legislation. As a final section, we start on a Road Map of how we might proceed to a National authentication infrastructure for Higher Education. We believe that such a system should be distributed in nature, and could well leverage on the investment already made in an X.500 distributed directory system. It is clear that the current technology would need considerable updating; much broader involvement must be achieved from other sectors of the universities for such an initiative to have broad impact. We mention some of the measures that should be undertaken to enable a successful broader applicability. Based on the existence of a National directory system, we then propose a National authentication infrastructure by proposing a system of Certification Authorities, distributed registration and update, and the retention of the certificates in the National directory system. We propose that existing projects in secure E-mail and electronic libraries be asked how they might be modified if such an infrastructure was developed.A substantial distributed infrastructure for authentication could have implication well beyond the university sector. For this reason, it may be possible to co-fund the development and many of the earlier trials from sources outside JISC. We propose that we explore avenues of co-funding both from the British Foresight Programme and from the European Union Telematics programme.<br/

A secure architecture enabling end-user privacy in the context of commercial wide-area location-enhanced web services

Mobile location-based services have raised privacy concerns amongst mobile phone users who may need to supply their identity and location information to untrustworthy third parties in order to access these applications. Widespread acceptance of such services may therefore depend on how privacy sensitive information will be handled in order to restore users’ confidence in what could become the “killer app” of 3G networks. The work reported in this thesis is part of a larger project to provide a secure architecture to enable the delivery of location-based services over the Internet. The security of transactions and in particular the privacy of the information transmitted has been the focus of our research. In order to protect mobile users’ identities, we have designed and implemented a proxy-based middleware called the Orient Platform together with its Orient Protocol, capable of translating their real identity into pseudonyms. In order to protect users’ privacy in terms of location information, we have designed and implemented a Location Blurring algorithm that intentionally downgrades the quality of location information to be used by location-based services. The algorithm takes into account a blurring factor set by the mobile user at her convenience and blurs her location by preventing real-time tracking by unauthorized entities. While it penalizes continuous location tracking, it returns accurate and reliable information in response to sporadic location queries. Finally, in order to protect the transactions and provide end-to-end security between all the entities involved, we have designed and implemented a Public Key Infrastructure based on a Security Mediator (SEM) architecture. The cryptographic algorithms used are identitybased, which makes digital certificate retrieval, path validation and revocation redundant in our environment. In particular we have designed and implemented a cryptographic scheme based on Hess’ work [108], which represents, to our knowledge, the first identity-based signature scheme in the SEM setting. A special private key generation process has also been developed in order to enable entities to use a single private key in conjunction with multiple pseudonyms, which significantly simplifies key management. We believe our approach satisfies the security requirements of mobile users and can help restore their confidence in location-based services

An investigation of issues of privacy, anonymity and multi-factor authentication in an open environment

This thesis performs an investigation into issues concerning the broad area ofIdentity and Access Management, with a focus on open environments. Through literature research the issues of privacy, anonymity and access control are identified. The issue of privacy is an inherent problem due to the nature of the digital network environment. Information can be duplicated and modified regardless of the wishes and intentions ofthe owner of that information unless proper measures are taken to secure the environment. Once information is published or divulged on the network, there is very little way of controlling the subsequent usage of that information. To address this issue a model for privacy is presented that follows the user centric paradigm of meta-identity. The lack of anonymity, where security measures can be thwarted through the observation of the environment, is a concern for users and systems. By an attacker observing the communication channel and monitoring the interactions between users and systems over a long enough period of time, it is possible to infer knowledge about the users and systems. This knowledge is used to build an identity profile of potential victims to be used in subsequent attacks. To address the problem, mechanisms for providing an acceptable level of anonymity while maintaining adequate accountability (from a legal standpoint) are explored. In terms of access control, the inherent weakness of single factor authentication mechanisms is discussed. The typical mechanism is the user-name and password pair, which provides a single point of failure. By increasing the factors used in authentication, the amount of work required to compromise the system increases non-linearly. Within an open network, several aspects hinder wide scale adoption and use of multi-factor authentication schemes, such as token management and the impact on usability. The framework is developed from a Utopian point of view, with the aim of being applicable to many situations as opposed to a single specific domain. The framework incorporates multi-factor authentication over multiple paths using mobile phones and GSM networks, and explores the usefulness of such an approach. The models are in tum analysed, providing a discussion into the assumptions made and the problems faced by each model.Adobe Acrobat Pro 9.5.1Adobe Acrobat 9.51 Paper Capture Plug-i

Security performance and protocol consideration in optical communication system with optical layer security enabled by optical coding techniques

With the fast development of communication systems, network security issues have more and more impact on daily life. It is essential to construct a high degree of optical layer security to resolve the security problem once and for all. Three different techniques which can provide optical layer security are introduced and compared. Optical chaos can be used for fast random number generation. Quantum cryptography is the most promising technique for key distribution. And the optical coding techniques can be deployed to encrypt the modulated signal in the optical layer. A mathematical equation has been derived from information theory to evaluate the information-theoretic security level of the wiretap channel in optical coding schemes. And the merits and limitation of two coherent optical coding schemes, temporal phase coding and spectral phase coding, have been analysed. The security scheme based on a reconfigurable optical coding device has been introduced, and the corresponding security protocol has been developed. By moving the encryption operation from the electronic layer to the optical layer, the modulated signals become opaque to the unauthorised users. Optical code distribution and authentication is the one of the major challenges for our proposed scheme. In our proposed protocol, both of the operations are covered and defined in detail. As a preliminary draft of the optical code security protocol, it could be a useful guidance for further research

Deniable Key Exchanges for Secure Messaging

Despite our increasing reliance on digital communication, much of our online discourse lacks any security or privacy protections. Almost no email messages sent today provide end-to-end security, despite privacy-enhancing technologies being available for decades. Recent revelations by Edward Snowden of government surveillance have highlighted this disconnect between the importance of our digital communications and the lack of available secure messaging tools. In response to increased public awareness and demand, the market has recently been flooded with new applications claiming to provide security and privacy guarantees. Unfortunately, the urgency with which these tools are being developed and marketed has led to inferior or insecure products, grandiose claims of unobtainable features, and widespread confusion about which schemes can be trusted. Meanwhile, there remains disagreement in the academic community over the definitions and desirability of secure messaging features. This incoherent vision is due in part to the lack of a broad perspective of the literature. One of the most contested properties is deniability—the plausible assertion that a user did not send a message or participate in a conversation. There are several subtly different definitions of deniability in the literature, and no available secure messaging scheme meets all definitions simultaneously. Deniable authenticated key exchanges (DAKEs), the primary cryptographic tool responsible for deniability in a secure messaging scheme, are also often unsuitable for use in emerging applications such as smartphone communications due to unreasonable resource or network requirements. In this thesis, we provide a guide for a practitioner seeking to implement deniable secure messaging systems. We examine dozens of existing secure messaging protocols, both proposed and implemented, and find that they achieve mixed results in terms of security. This systematization of knowledge serves as a resource for understanding the current state-of-the-art approaches. We survey formalizations of deniability in the secure messaging context, as well as the properties of existing DAKEs. We construct several new practical DAKEs with the intention of providing deniability in modern secure messaging environments. Notably, we introduce Spawn, the first non-interactive DAKE that offers forward secrecy and achieves deniability against both offline and online judges; Spawn can be used to improve the deniability properties of the popular TextSecure secure messaging application. We prove the security of our new constructions in the generalized universal composability (GUC) framework. To demonstrate the practicality of our protocols, we develop and compare open-source instantiations that remain secure without random oracles

Proposed Model for Outsourcing PKI

PKI is often referred to as a pervasive substrate. This terminology is used to describe the technological layer that permeates the entirety of the organisation on which PKI services are established. From the mid 1970s when Whitfield Diffie and Martin Hellman published their paper New Directions in Cryptography the concept of Public Key Cryptography, for the first time, allowed two entities with no previous relationship to communicate secure information over unsecured channels. PKI provides the infrastructure that allows Public Key Cryptography to function within a hierarchical structure, providing between two entities, an acceptable level of trust. Outsourcing is the process of acquiring sources or services from an external source. With the modular structure of today's organisations it can also mean that goods and services can be procured from one segment of the organisation to another through inhouse service-supplier agreements. Outsourcing has evolved from the days of heavy industry and manufacturing in the 1960s to the total solution management of today. This dissertation brings together the concepts of both PKI and Outsourcing. It details our AB-5C Model for organisations to outsource a PKI system within the scope of the businesses strategic goals and objectives. Our proposed model takes into account the need to use existing models, procedures and practices in support of an outsourced PKI Model. These include a process or processes to ensure that any outsourced solution adds value to the organisation, and that there is a business strategy that allows the alignment of the outsourcing strategy to the organisations strategic plan