A Multi-Conditional Proxy Broadcast Re-Encryption Scheme for Sensor Networks

In sensor networks, it is a challenge to ensure the security of data exchange between packet switching nodes holding different private keys. In order to solve this problem, the present study proposes a scheme called multi-conditional proxy broadcast reencryption (MC-PBRE). The scheme consists of the following roles: the source node, proxy server, and the target node. If the condition is met, the proxy can convert the encrypted data of the source node into data that the target node can directly decrypt. It allows the proxy server to convert the ciphertext of the source node to a new ciphertext of the target node in a different group, while the proxy server does not need to store the key or reveal the plaintext. At the same time, the proxy server cannot obtain any valuable information in the ciphertext. This paper formalizes the concept of MC-PBRE and its security model, and proposes a MC-PBRE scheme of ciphertext security. Finally, the scheme security has been proved in the random oracle.