Key issuing scheme focuses on the confidentiality maintained in using the secret key for communication in p2p networks. Identity based cryptography (IBC) was introduced into peer-to-peer (P2P) networks
BACKGROUNDWith its distributed, self-organization and self maintenance nature, P2P networks are extremely vulnerable to a large spectrum of attacks [1], mainly due to the lack of a certification service responsible for peers identity verification and for authentication purposes. Traditional certificate-based public key infrastructure (PKI) was used to solve some of the problems by verifying the authenticity of nodes' identities and issuing public key certificate to each node. However, as the node churn is highly frequent in the P2P network, many nodes that stored certificates may quickly become invalid, hence PKI based security protocol is difficult to be deployed. Besides, each node requires large amounts of space to store public key certificates, which can be difficult to implement in practice.Furthermore, secured P2P overlay communication is efficient if the overlay nodes have a common, shared key for securing the communication. This is difficult to achieve in dynamic P2P overlay networks, as a new key must be generated every time an overlay node membership change occurs in order to preserve forward secrecy. Compared with the PKI technique, identity based cryptography (IBC) can simplify the key management process in P2P networks significantly. The identity of a peer (e.g., peer identifier or peer geometric coordinate) in P2P overlay networks is used to create its public key, thus avoiding the use of any certificates. These IBC-based systems are scalable, simple to administer, and each user can carry out anytime/anywhere encryption, establish secure communication channels, prove its identity to other nodes, verify protected messages and produce a form of signature with non-repudiation property.