A storage unit 104 of an address management apparatus 100 stores translation information 104C that associates, one-to-one, a value that can be taken by data in a block of a translation object address, with its post-translation value. An address translation unit 1032 reads, from the translation information 104C, a post-translation value associated with a value indicated by data of each block defined in the translation object IP address. Data of each block of the translation object address is translated based on the read post-translation value. This improves security in cases where access log data is provided to a third party.