Secure Group Communication with Hidden Group Key

Grid environment is mainly concerned with sharing diverse resources belonging to different administrative domains. Security and scalability are important issues for secure group communication in a grid environment. Secure group communication among group members working on collaborative tasks involves confidentiality and authenticity of the message and the session key. In order to transmit the data in a secure way, a suitable key transfer protocol should be implemented. Key transfer protocols rely on a centralized Key Management Center (KMC), an entity responsible for managing user authentication, generating group keys and distributing it to all the members of the communicating group secretly. In this paper, we proposed a secure key transfer protocol that uses the concepts of soft dipole representation of the image and steganography for transferring password and group key securely to the users. In this protocol, users submit their images at the time of registration with the KMC. First KMC compute the soft dipole representation S I of every user's image and each user's image can be uniquely represented by its corresponding soft dipole representation. The soft dipole representation of each user's image is used as a password for authentication of corresponding user with KMC. KMC generates the group key using soft dipoles of the images of the group members. To preserve the confidentiality, the group key is embedded into an image (using information hiding technique) and KMC broadcast that image to all the group members.