In a predicate encryption scheme an authority generates master public and secret keys, and uses the master secret key to derive personal secret keys for authorized users. Each user’s personal secret key SKf corresponds to a predicate f defining the access rights of that user, and each ciphertext is associated (by the sender) with an attribute. The security provided is that a ciphertext associat...

Device authentication can reinforce the security of the home network services by ensuring that only specific authorized devices by specific authorized users can access the services. And it is also a mandatory technology for context-aware services in which users are not participant in the service flow. In this paper, we propose a device authentication and access control scheme based on two-layer...

Hierarchical Mobile IPv6 (HMIPv6) is a protocol that enhances Mobile IPv6 (MIPv6) with faster handovers. Neither HMIPv6 nor MIPv6 provides ways to authenticate roaming mobile nodes, although visited networks will need to check if mobile nodes can be authorized access. A solution is required before MIPv6 can be commonly deployed. Mechanisms to integrate Mobile IPv4 and the Diameter protocol for ...

This thesis extends DRM schemes which address the problem of unauthorized proprietary content sharing in home networks to address the problem of unauthorized confidential content sharing in organizations. In particular it focuses on how to achieve secure content sharing between employees in a group while limiting content leakage to unauthorized individuals outside the group. The thesis discusse...

Public Key Cryptography enables entity authentication protocols based on a platform’s knowledge of other platforms’ public key. This is particularly advantageous for embedded systems, such as FPGA platforms, with limited or none read-protected memory resources. For access control systems, an access token is authenticated by the mobile system. Only the public key of authorized tokens needs to be...

Reverse micelles in the AOT/water/isooctane system, at various water contents (W(0)), were studied using rheometry and small angle X-ray scattering (SAXS) experiments under static conditions and under shear. The SAXS analysis confirmed the spherical shape of the micelles at low water content and revealed a transition into elongated micelles at higher water content. A population of spherical mic...

We obtain the diffusion matrix, D, consisting of the main and cross-diffusion coefficients for a loaded AOT microemulsion, a quaternary system containing water (1)/AOT (2)/species (3)/octane (4). Here "species" is a component of the Belousov-Zhabotinsky reaction: NaBr, NaBrO(3), bathoferroin, ferroin, or Br(2). The main and cross-diffusion coefficients of each species depend crucially on its so...

Pervasive-computing infrastructures necessarily collect a lot of context information to disseminate to their contextaware applications. Due to the personal or proprietary nature of much of this context information, however, the infrastructure must limit access to context information to authorized persons. In this paper we propose a new access-control mechanism for event-based contextdistributio...