Abstract: A lightweight attribute-based signcryption (ABSC) method for cloud-fog-assisted Internet-of-things: performing, by a central authority, system initialization to generate a system key pair, and disclosing a public key, the public key including a symmetric encryption algorithm (SEA) and a key derivation function (KDF); generating, by the central authority, a decryption key and an outsourcing decryption key based on a decryption attribute set of a data user, and generating a signature key and an outsourcing signature key based on a signature access structure; calling, by a data owner, a fog node for outsourcing signature, performing symmetric encryption on a plaintext based on a symmetric key, and performing ABSC on the symmetric key based on a defined encryption access structure; and calling, by the data user, a fog node for outsourcing signature verification, calling a fog node for outsourcing decryption, and performing symmetric decryption on a ciphertext based on an outsourcing decryption result.

Abstract: An ABE method with multiple tracing attribute authorities: performing, by a central authority, system initialization to generate a public parameter and disclosing the public parameter; performing, by each of attribute authorities, initialization to generate a key pair, and disclosing a public key in the key pair; performing, by a data owner, symmetric encryption on plaintext data, performing ABE on a symmetric key based on a hidden access structure, and generating an integrity verification value; requesting, by a data user, a decryption key to the attribute authority according to an own attribute; restoring, by the data user in response to decryption, an access structure, generating an outsourcing decryption key, sending the outsourcing decryption key to a cloud storage center for semi-decryption; generating, by the cloud storage center, a semi-decrypted ciphertext, and feeding the semi-decrypted ciphertext back to the data user; fully decrypting the semi-decrypted ciphertext according to a private decryption

Abstract: A lightweight attribute-based signcryption (ABSC) method for cloud-fog-assisted Internet-of-things: performing, by a central authority, system initialization to generate a system key pair, and disclosing a public key, the public key including a symmetric encryption algorithm (SEA) and a key derivation function (KDF); generating, by the central authority, a decryption key and an outsourcing decryption key based on a decryption attribute set of a data user, and generating a signature key and an outsourcing signature key based on a signature access structure; calling, by a data owner, a fog node for outsourcing signature, performing symmetric encryption on a plaintext based on a symmetric key, and performing ABSC on the symmetric key based on a defined encryption access structure; and calling, by the data user, a fog node for outsourcing signature verification, calling a fog node for outsourcing decryption, and performing symmetric decryption on a ciphertext based on an outsourcing decryption result.

Abstract: An ABE method with multiple tracing attribute authorities: performing, by a central authority, system initialization to generate a public parameter and disclosing the public parameter; performing, by each of attribute authorities, initialization to generate a key pair, and disclosing a public key in the key pair; performing, by a data owner, symmetric encryption on plaintext data, performing ABE on a symmetric key based on a hidden access structure, and generating an integrity verification value; requesting, by a data user, a decryption key to the attribute authority according to an own attribute; restoring, by the data user in response to decryption, an access structure, generating an outsourcing decryption key, sending the outsourcing decryption key to a cloud storage center for semi-decryption; generating, by the cloud storage center, a semi-decrypted ciphertext, and feeding the semi-decrypted ciphertext back to the data user; fully decrypting the semi-decrypted ciphertext according to a private decryption