OceanStore is a utility infrastructure designed to span the globe and provide continuous access to persistent information. Since this infrastructure is comprised of untrusted servers, data is protected through redundancy and cryptographic techniques. To improve performance, data is allowed to be cached anywhere, anytime. Additionally, monitoring of usage patterns allows adaptation to regional outages and denial of service attacks; monitoring also enhances performance through pro-active movement of data. A prototype implementation is currently under development. 1

We address the problem of authorization in large-scale, open...

SPKI/SDSI is a novel public-key infrastructure emphasizing naming, groups, ease-of-use, and flexible authorization. To access a protected resource, a client must present to the server a proof that the client is authorized; this proof takes the form of a "certificate chain " proving that the client's public key is in one of the groups on the resource's ACL, or that the client's public key has been delegated authority (in one or more stages) from a key in one of the groups on the resource's ACL. While finding such a chain can be nontrivial, due to the flexible naming and delegation capabilities of SPKI/SDSI certificates, we present a practical and efficient algorithm for this problem of "certificate chain discovery. " We also present a tight worst-case bound on its running time, which is polynomial in the length

Abstract not found

This document is one of three, superseding the draft filed under the name draft-ietf-spki-cert-theory-00.txt. SPKI structure definitions are to be found in draft-ietf-spki-cert-structure-*.txt and examples of certificate uses are to be found in draft-ietf-spki-certexamples-*.txt. Distribution of this document is unlimited. Comments should be sent to the SPKI (Simple Public Key Infrastructure) Working Group mailing list <spki@c2.net> or to the authors. This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months. Internet-Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet-Drafts as reference material or to cite them other than as a ‘‘working draft’ ’ or ‘‘work in progress.’’ Ellison, et al. [Page 1] INTERNET-DRAFT SPKI Certificate Theory 10 March 1998 To learn the current status of any Internet-Draft, please check the 1id-abstracts.txt listing contained in the Internet-Drafts Shadow

We describe the design, implementation, and performance of a new system for access control on the web. To achieve greater flexibility in forming access-control policies -- in particular, to allow better interoperability across administrative boundaries -- we base our system on the ideas of proof-carrying authorization (PCA). We extend PCA with the notion of goals and sessions, and add a module system to the proof language. Our access-control system makes it possible to locate and use pieces of the security policy that have been distributed across arbitrary hosts. We provide a mechanism which allows pieces of the security policy to be hidden from unauthorized clients. Our system is implemented as modules that extend a standard web server and web browser to use proof-carrying authorization to control access to web pages. The web browser generates proofs mechanically by iteratively fetching proof components until a proof can be constructed. We provide for iterative authorization, by which a server can require a browser to prove a series of challenges. Our implementation includes a series of optimizations, such as speculative proving, and modularizing and caching proofs, and demonstrates that the goals of generality, flexibility, and interoperability are compatible with reasonable performance.

We present a distributed algorithm for assembling a proof that a request satisfies an access-control policy expressed in a formal logic, in the tradition of Lampson et al. [16]. We show analytically that our distributed proofgeneration algorithm succeeds in assembling a proof whenever a centralized prover utilizing remote certificate retrieval would do so. In addition, we show empirically that our algorithm outperforms centralized approaches in various measures of performance and usability, notably the number of remote requests and the number of user interruptions. We show that when combined with additional optimizations including caching and automatic tactic generation, which we introduce here, our algorithm retains its advantage, while achieving practical performance. Finally, we briefly describe the utilization of these algorithms as the basis for an access-control framework being deployed for use at our institution. 1.

We describe the design and implementation of Grey, a set of software extensions that convert an off-the-shelf smartphone-class device into a tool by which its owner exercises and delegates her authority to both physical and virtual resources. We describe the software architecture and user interfaces of Grey, and then detail two initial case studies in which we have converted infrastructure to accommodate requests from Grey-enabled devices. The first is two floors (nearly 30,000 square feet) of office space, in which we are equipping over 65 doors for access control using Grey for a population of roughly 150 persons. The second is modifications to Windows XP that permit login via Grey-enabled phones. We provide preliminary evaluations of these efforts and directions for research to further the vision of a unified authorization framework for both physical and virtual resources.

We present a constructive authorization logic where the meanings of connectives are defined by their associated inference rules. This ensures that the logical reading of access control policies expressed in the logic and their implementation coincide. We study the proof-theoretic consequences of our design including cut-elimination and two non-interference properties that allow administrators to explore the correctness of their policies by establishing that for a given policy, assertions made by certain principals will not affect the truth of assertions made by others.

for enforcing strong end-to-end confidentiality and integrity policies. Such policies, however, are usually specified in term of static information---data is labeled high or low security at compile time. In practice, the confidentiality of data may depend on information available only while the system is running This paper studies language support for run-time principals, a mechanism for specifying information-flow security policies that depend on which principals interact with the system. We establish the basic property of noninterference for programs written in such language, and use run-time principals for specifying run-time authority in downgrading mechanisms such as declassification.