In one embodiment, a device executes reading and writing for a storage unit storing a table tree and verifier tree. The table tree includes a parent table and child table. The verifier tree includes a parent verifier associated with the parent table, and a child verifier associated with the child table. The parent verifier is used for verifying the child table and the child verifier. The device stores a secure table tree being a part of the table tree and used for address translation, and a secure verifier tree being a part of the verifier tree, to a secure storage unit. The device, when data has a read-only attribute, calculates verification information based on the data and a secure value varying according as the data is updated, and executes verification based on a verifier corresponded to the data and the verification information.