| 摘要 |
According to an embodiment, an encryption device includes a symmetric-key operation unit; a division unit; an exclusive OR operation unit; a multiplication unit that performs multiplication on a Galois field; and a control unit that controls the above units. When the input data is divided into blocks, with the predetermined length, and the first mode of operation is designated on a (j−1)-th block, the control unit performs control such that the multiplication unit performs multiplication with a predetermined value based on the (j−1)-th block, performs control such that the exclusive OR operation unit sums a multiplication result and data of a j-th block, and performs control such that the exclusive OR operation unit sums an operation result of the exclusive OR operation unit and an operation result of the multiplication unit on the (j−1)-th block. |
