Searchable Attribute-Based Signcryption Scheme for Electronic Personal Health Record

Considering the scenario of an electronic personal health record system, we put forward a new cryptographic concept called searchable attribute-based signcryption, which can support fine-grained access control, data privacy, data authenticity, and data searchability. Then, we establish the security models and construct a searchable attribute-based signcryption scheme with hybrid access policy. According to the proposed security model frameworks, our scheme is proven to achieve: 1) ciphertext indistinguishability under the decisional bilinear Diffie-Hellman exponent hardness assumption; 2) existential unforgeability based on the hardness assumption of computational Diffie-Hellman exponent problem; 3) selective security against chosen-keyword attack under the static assumption in the generic group model; and 4) keyword secrecy based on the one-way hardness of hash function. Furthermore, the experimental results show that the proposed scheme is efficient.