公开(公告)号：US20240056314A1

公开(公告)日：2024-02-15

申请号：US18260545

申请日：2021-10-11

Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA

Inventor： Naoki YAMAMURO ,  Junya WATANABE ,  Shigeki MATSUMOTO ,  Yoshikazu JIKUHARA ,  Ryota SUZUKI ,  Yuki YAMASHITA ,  Hitoshi MURAKAMI

IPC: H04L9/32 ,  H04L9/00

CPC classification number: H04L9/3263 ,  H04L9/50 ,  H04L9/3297

Abstract: A data management system includes a plurality of data management apparatuses, a certification authority group, and a time stamp authority group. In making an application for a proof of existence of invention information, the data management apparatus generates an invention hash, and transmits the invention hash to selected time stamp authorities of the time stamp authority group. Each of the time stamp authorities having received the invention hash generates a time stamp token. The data management apparatus acquires the time stamp token from each of the plurality of time stamp authorities to which the invention hash has been transmitted.