Attribute‐Based Encryption

This chapter describes attribute‐based encryption (ABE) and its advantages over the current cryptographic scheme. ABE provides less key overhead than other public key encryption algorithms, such as RSA, ElGamal, and identity‐based encryption, when multiple users with varying access privileges exchange encrypted data. As ABE employs an access structure based on attributes in either the ciphertext or the secret key, it is able to provide fine‐grained access control with the guarantee that a user can only decrypt a message if they satisfy the constraints imposed by the access structure. Important aspects of ABE are reviewed in this chapter, including the secret‐sharing scheme, access structure constructions, properties, bilinear pairing, cryptographic assumptions, and security notions.