Fuzzy matching and direct revocation: a new CP-ABE scheme from multilinear maps

In the attribute-based encryption (ABE) systems, users could encrypt and decrypt messages based on some attributes or access policies. Due to the functionality and flexibility of ABE, it is considered to be very suitable for secure data sharing in cloud storage environment. However, in the real world, users’ access rights are often dynamic; therefore, we need ABE schemes to support revocation to meet this requirement. In this work, we construct a novel directly revocable ciphertext-policy ABE (DR-CP-ABE) scheme based on the multilinear maps and prove its selective security under \((d+3)\)-multilinear decisional Diffie–Hellman assumption in the random oracle model. In addition, we extend our DR-CP-ABE scheme to support verifiable ciphertext delegation property.