The invention discloses a 
blockchain-based 
digital asset processing method and device. The method comprises the following steps: receiving private 
ciphertext for a 
digital asset circulated from a sending end to a receiving end through a 
blockchain, and a preset public key; and obtaining a sharing public key for sharing the private 
ciphertext based on the preset public key, so that when the private 
ciphertext and the sharing public key are broadcast in the 
blockchain, blockchain nodes on the blockchain can share the private ciphertext based on the sharing public key and reach a blind 
consensus on the shared private ciphertext, and after the 
consensus on the private ciphertext is reached, the private ciphertext can be decrypted by at least one of three parties, i.e., the sending end, the receiving end and a monitoring end, based on a preset private key to obtain 
plaintext of the 
digital asset. The method and device provided by the embodiment of the invention has the advantages that the privacy right of a user is protected; under the premise of 
privacy protection, the single general digital asset can be smoothly circulated within one blockchain or among multiple blockchains, and a total 
currency amount remains unchanged; and a monitoring party other than the transaction parties can monitor transaction information at any time.