US 12,445,291 B2
Data management device, data management method, and non-transitory storage medium
Naoki Yamamuro, Nagoya (JP); Shigeki Matsumoto, Nagoya (JP); Yohei Nakanishi, Nagoya (JP); Kazuya Kumazawa, Nagoya (JP); and Wataru Fukatsu, Tokyo (JP)
Assigned to TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); and SCALAR, INC., Shinjuku-ku (JP)
Filed by TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota (JP); and Scalar, Inc., Tokyo (JP)
Filed on Mar. 29, 2024, as Appl. No. 18/622,270.
Claims priority of application No. 2023-060208 (JP), filed on Apr. 3, 2023.
Prior Publication US 2024/0333516 A1, Oct. 3, 2024
Int. Cl. H04L 29/06 (2006.01); H04L 9/00 (2022.01); H04L 9/32 (2006.01)
CPC H04L 9/3236 (2013.01) [H04L 9/3213 (2013.01); H04L 9/3297 (2013.01); H04L 9/50 (2022.05)] 12 Claims
OG exemplary drawing
 
1. A data management device comprising:
a storage storing a distributed ledger, the distributed ledger including a plurality of evidence chains and a time stamp chain, the plurality of evidence chains storing in chronological order at least one hash value, the time stamp chain storing in chronological order at least one time stamp token, each hash value being generated from a file, and each time stamp token certifying a time of confirmation; and
a processor configured to repeatedly execute an update process such that the time stamp chain is updated, the update process including a process for identifying, out of the evidence chains, at least one evidence chain in which the hash value has been changed with a change in the file since previous execution of the update process, and acquiring the time stamp token for a terminal value generated based on a terminal hash value of the at least one evidence chain.