IPv6 mobility is an IETF standard that has added roaming capabilities of mobile node (MN). It allows MNs to travel from one network to another without any distraction in communication service. MNs register their current location to home stations and correspondent hosts via a process known as binding update. In IPv6 mobility, return routability protocol (RRP) is a standard procedure for updating the current location of MNs through binding update message to their communicants. However, RRP has several security threats and issues. Subsequently, RRP was integrated with identity-based encryption for improvement of security. Nevertheless, it suffers from some limitations such as inherent key escrow problem, lack of key revocation, high computational load and latency while providing security. Hence, this paper proposes a novel approach called optimised RRP using certificateless public key encryption to address these issues. The proposed protocol is simulated and validated using Automated Validation of Internet Security Protocols and Applications (AVISPA)-a model checker. Finally, the simulation and numerical results illustrate the extent to which the proposed protocol surpasses the existing method in terms of enhanced security and significant reduction in communication payload with minimised latency.

Cloud computing is a model for enabling convenient, on demand network access to a shared pool of computing resources. The cloud storage system consists of a collection of storage servers and key servers. Storing data in a third party cloud system causes serious concern on data confidentiality, so a user divides the data into blocks, encrypts and stores them in various storage servers. The storage server encodes the data using erasure codeword symbol. When the sender wants to share his messages, he sends a re-encryption key to the storage server. The storage server re-encrypts the original codeword symbol into a re-encrypted codeword symbol. The re-encryption scheme is integrated with a secure decentralized erasure code so that a secure distributed system is designed. The proxy re-encryption scheme supports the encoding operations over encrypted messages as well as forwarding operations. The key server retrieves re-encrypted codeword symbols and performs partial decryption so that the receiver combines the blocks to retrieve the data.