Cross-domain encryption scheme with equality test for wireless body area networks

Wireless body area networks (WBANs) are rapidly becoming a vital component of the medical industry, in which massive body data is encrypted and then uploaded to the cloud server. In order to search for the encrypted data, the concept of public key encryption adopting equality test has been presented. However, previous schemes of equality test require communication entities in different domain networks to share the same cryptographic parameters, which is not suitable for the cross-domain environment. To break this restraint, we propose a cross-domain encryption scheme with equality test using different parameters for WBANS, in which ciphertexts are from certificateless crypto system (CLC) to identity-based crypto system (IBC). Through the rigorous security analysis, our scheme can carry out the one-way security under a chosen identity attack (OW-ID-CCA) as well as the known session-specific temporary information security (KSTIS). Moreover, the detailed efficiency analysis shows that our scheme saves at least 11% of the total computation cost over four latest schemes.