In identity-based public-key cryptography, an entity’s public key can be easily derived from its identity. The direct derivation of public keys in identity-based public-key cryptography eliminates the need for certificates and solves certain public key management problems in traditional public-key cryptosystems. Recently, the notion of asymmetric group key agreement was introduced, in which the...

In the last few years, multicasting is increasingly used as an efficient communication mechanism for group-oriented applications in the Internet. Some multicast applications require confidentiality for transmitted data. So, a traffic encryption key is used to assure this confidentiality and has to be changed and distributed to all valid members whenever a membership change (join or leave) occur...

Group-oriented services are attractive to both customers and service providers since they allow for potential markets that exploit user collaboration and shared experiences. In order to protect the content of a group service, the content must be encrypted using a key shared by group members. With the advancement of network technologies, customers will access group services from different networ...

In the secure group communication, data is transmitted in such a way that only the group members are able to receive the messages. The main problem in the solution using symmetric key is heavy re-keying cost. To reduce re-keying cost tree based architecture is used. But it requires extra overhead to balance the keytree in order to achieve logarithmic re-keying cost. The main challenging issue i...