Provided is a method for blockchain-based recordkeeping and implementable by a terminal device. The method comprises: obtaining target data; computing a data digest of the target data, and extracting a key segment from the target data; signing, in a secure operation environment included in the terminal device, the data digest and/or the key segment based on a private key associated with the terminal device to generate a signature; and submitting to a blockchain the data digest, the key segment, and the signature, for one or more nodes in the blockchain to verify the signature based on a public key corresponding to the private key, and to record the data digest and the key segment in the blockchain in response to the signature being verified to be valid.