A permission terminal generates access information for content using a content public key of the content and a user public key of a browser of the content, and registers the access information in a blockchain. The access information includes an aggregate public key generated by aggregating the content public key and the user public key, a message for the content, and a content signature obtained by signing the message with a content private key corresponding to the content public key. A browsing terminal acquires access information of requested content from a blockchain and verifies, with the aggregate public key, an aggregate signature where a user signature in which a message of the access information is signed with a user private key and the content signature of the access information are aggregated, and transmits a content request including the user signature or the aggregate signature if the verification succeeds.