Alibaba Group Holding Limited
Ciphertext preprocessing and acquisition

Abstract:

A computer-implemented method includes: obtaining, by a data party, a piece of plaintext to be encrypted; generating a ciphertext file including multiple pieces of ciphertext, each piece of ciphertext being derived from a homomorphic encryption algorithm executed on the piece of plaintext; adding a first file identifier of the ciphertext file to a file identifier set corresponding to the piece of plaintext; and in response to a piece of ciphertext derived from the piece of plaintext being needed for a cooperative calculation in which the data party is participating: obtaining the first file identifier from the file identifier set corresponding to the piece of plaintext, reading a first piece of ciphertext from the ciphertext file identified by the first file identifier, and sending the first piece of ciphertext to a partner participating in the cooperative calculation.