"Due to the lack of a centralized server in “Peer-to-Peer” (P2P) networks, users are responsible for the security of these networks. One of the security issues in P2P networks is the security of the message routing. Messages could be altered or modified by attackers while being routed. The conventional security method to avoid this has been “Public Key Cryptography” (PKC). To avoid the certificate management issue in PKC, “Identity-based Encryption” (IBE) has been suggested in which any arbitrary string could be used as a public key. Since IBE is a computationally expensive method, current proposed IBE-based methods are not effective in the message routing phase in P2P networks and highly affect the performance of message delivery time in these networks. This thesis proposes two IBE-based protocols that can be applied effectively to the message routing phase of structured P2P networks, yet provide a satisfactory message delivery time performance. Both protocols benefit from Identity-based key exchange scheme and, therefore, none of them impose any extra communication on the network to secure message routing. Protocol 1 significantly improves the performance of message delivery time compared to the current IBE-based proposed methods. Protocol 2, which requires nodes to store data, has a performance similar to the situations in which no security measures are applied for message routing."
Secure message routing in structured peer-to-peer networks
