Safely outsourced attribute-based encryption method

The invention discloses a safely outsourced attribute-based encryption method, which supports outsourcing for secret key distribution and decryption. The method comprises the following steps: (1) system establishing; (2) initialization of outsourcing secret key generation; (3) generation of an external secret key; (4) generation of an internal secret key; (5) blinding of conversion secret key; (6) encryption; (7) partial decryption; and (8) complete decryption. The safely outsourced encryption method has the advantages of simple construction process and high transmission efficiency and can be used for realizing fine-grained resource access control under a cloud computing environment, and a large amount of expenditure is saved for attribute authorities and users.