23,020 research outputs found

    Access right management by extended password capabilities

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    With reference to a classic protection system featuring active subjects that reference protected objects, we approach the problem of identifying the objects that each subject can access, and the operations that the subject can carry out on these objects. Password capabilities are a classical solution to this problem. We propose a new form of password capability, called extended password capability (or e-capability, for short). An e-capability can specify any combination of access rights. A subject that holds a given e-capability can generate new e-capabilities for reduced sets of access rights. Furthermore, a subject that created a given object is in a position to revoke the access permissions granted by every e-capability referencing this object, completely or in part. The size of an e-capability is comparable to that of a traditional password capability. The number of passwords that need to be stored in memory permanently is kept to a minimum, and is equal to a single password for each object

    Citizen Electronic Identities using TPM 2.0

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    Electronic Identification (eID) is becoming commonplace in several European countries. eID is typically used to authenticate to government e-services, but is also used for other services, such as public transit, e-banking, and physical security access control. Typical eID tokens take the form of physical smart cards, but successes in merging eID into phone operator SIM cards show that eID tokens integrated into a personal device can offer better usability compared to standalone tokens. At the same time, trusted hardware that enables secure storage and isolated processing of sensitive data have become commonplace both on PC platforms as well as mobile devices. Some time ago, the Trusted Computing Group (TCG) released the version 2.0 of the Trusted Platform Module (TPM) specification. We propose an eID architecture based on the new, rich authorization model introduced in the TCGs TPM 2.0. The goal of the design is to improve the overall security and usability compared to traditional smart card-based solutions. We also provide, to the best our knowledge, the first accessible description of the TPM 2.0 authorization model.Comment: This work is based on an earlier work: Citizen Electronic Identities using TPM 2.0, to appear in the Proceedings of the 4th international workshop on Trustworthy embedded devices, TrustED'14, November 3, 2014, Scottsdale, Arizona, USA, http://dx.doi.org/10.1145/2666141.266614

    Encrypted Shared Data Spaces

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    The deployment of Share Data Spaces in open, possibly hostile, environments arises the need of protecting the confidentiality of the data space content. Existing approaches focus on access control mechanisms that protect the data space from untrusted agents. The basic assumption is that the hosts (and their administrators) where the data space is deployed have to be trusted. Encryption schemes can be used to protect the data space content from malicious hosts. However, these schemes do not allow searching on encrypted data. In this paper we present a novel encryption scheme that allows tuple matching on completely encrypted tuples. Since the data space does not need to decrypt tuples to perform the search, tuple confidentiality can be guaranteed even when the data space is deployed on malicious hosts (or an adversary gains access to the host). Our scheme does not require authorised agents to share keys for inserting and retrieving tuples. Each authorised agent can encrypt, decrypt, and search encrypted tuples without having to know other agentsā€™ keys. This is beneficial inasmuch as it simplifies the task of key management. An implementation of an encrypted data space based on this scheme is described and some preliminary performance results are given

    SNS programming environment user's guide

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    The computing environment is briefly described for the Supercomputing Network Subsystem (SNS) of the Central Scientific Computing Complex of NASA Langley. The major SNS computers are a CRAY-2, a CRAY Y-MP, a CONVEX C-210, and a CONVEX C-220. The software is described that is common to all of these computers, including: the UNIX operating system, computer graphics, networking utilities, mass storage, and mathematical libraries. Also described is file management, validation, SNS configuration, documentation, and customer services
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