Wireless broadcast is an effective approach to disseminate data to a number of users. To provide secure access to data in wireless broadcast services, symmetric key based encryption is used to ensure that only users who own the valid keys can decrypt the data. Regarding various subscriptions, an efficient key management to distribute and change keys is in great demand for access control in broa...

The aim of this technical report is to complement the work in [To et al. 2014] by proposing a Group Key Exchange protocol so that the Querier and TDSs (and TDSs themselves) can securely create and exchange the shared key. Then, the security of this protocol is formally proved using the game-based model. Finally, we perform the comparison between this protocol and other related works.

In this work, we introduce an active attack on a Group Key Exchange protocol by Burmester and Desmedt. The attacker obtains a copy of the shared key, which is created in a collaborative manner with the legal users in a communication group.

Secure group communications are increasingly used in the continuous growth of the Internet applications. In a secure multicast environment, an identical data can be efficiently delivered from a source to multiple receivers within a dynamic group. A simple solution is to encrypt the transmitted data using a symmetric key. However, scalable group rekeying is the main challenge for large and dynam...

We extend Delaune, Kremer and Steel’s framework for analysis of PKCS#11-based APIs from bounded to unbounded fresh data. We achieve this by: formally defining the notion of an attribute policy ; showing that a well-designed API should have a certain class of policy we call complete; showing that APIs with complete policies may be safely abstracted to APIs where the attributes are fixed; and pro...

Security APIs are used to define the boundary between trusted and untrusted code. The security properties of existing APIs are not always clear. In this paper, we give a new generic API for managing symmetric keys on a trusted cryptographic device. We state and prove security properties for our API. In particular, our API offers a high level of security even when the host machine is controlled ...

Hierarchical Access Control in group communication is an active area of research which is difficult to achieve it. Its primary objective is to allow users of a higher authority group to access information or resource held by lower group users and preventing the lower group users to access information held by higher class users. Large collection of collaborative applications in organizations inh...

Key establishment between any pair of nodes is an essential requirement for providing secure services in wireless sensor networks. Blom’s scheme is a prominent key management scheme but its shortcomings include large computation overhead and memory cost. We propose a new scheme in this paper that modifies Blom’s scheme in a manner that reduces memory and computation costs. This paper also provi...