The invention discloses an attribute-based
encryption method and
system based on support of multi-authority accountability and outsourcing calculation, and the method specifically comprises the steps: introducing a multi-
attribute authority mechanism to be responsible for
key distribution and management, reducing the dependence on a single mechanism, and improving the safety and reliability of the
system; the
cloud server locally updates the access strategy and the
ciphertext according to the minimum change increment set uploaded by the data owner; a white-box tracking technology is adopted to bind a user identity with an attribute key, so that a
system can locate a specific identity of a malicious user and a specific identity of a malicious
attribute authority through a leaked key; intensive computing tasks in the
encryption and decryption processes are outsourced to a
cloud server, and meanwhile it is ensured that
user privacy is not leaked in the outsourcing process; for the untrusted problem of the
cloud server, the calculation result is verified by using the
smart contract in the block chain, and it is ensured that the
verification process is open and transparent and the result is trusted; and an attribute version mark is introduced, so that efficient
revocation of old version attributes is realized, and the safety is further improved.