| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a technique that enhances security of a ciphertext in a case of dividing encryption target data into fixed-length blocks, and encrypting each the block independently to generate the ciphertext.SOLUTION: A data acquisition unit 2020 acquires target data. An intermediate data generation unit 2040 generates intermediate data by converting, for each block of predetermined size acquired from the target data, partial data included in the block so as to be restorable with use of partial data included in a block different from the block. An encryption unit 2060 generates a ciphertext from the intermediate data by dividing the intermediate data for each the predetermined size to generate a plurality of encryption target blocks, and encrypting each the encryption target block independently.</p> |
