US 12,335,416 B2
Timestamp issuing method
Kunihiro Ishida, Tokyo (JP); and Tatsunori Yamagami, Tokyo (JP)
Assigned to NEC Solution Innovators, Ltd., Tokyo (JP)
Filed by NEC Solution Innovators, Ltd., Tokyo (JP)
Filed on Oct. 20, 2022, as Appl. No. 17/969,800.
Claims priority of application No. 2021-175484 (JP), filed on Oct. 27, 2021.
Prior Publication US 2023/0126583 A1, Apr. 27, 2023
Int. Cl. H04L 9/32 (2006.01); H04L 9/00 (2022.01)
CPC H04L 9/3297 (2013.01) [H04L 9/3236 (2013.01); H04L 9/50 (2022.05)] 8 Claims
OG exemplary drawing
 
1. A timestamp issuing method by a local timestamp issuing apparatus installed in an offline environment, the timestamp issuing method comprising:
in response to a request for a timestamp for electronic data by a predetermined information processing apparatus installed in a local environment same as the local timestamp issuing apparatus, issuing a timestamp token for the electronic data by adding time information to a hash value of the electronic data and digitally signing;
at a preset timing, connecting to a specific timestamp issuing apparatus installed on Internet, and requesting a timestamp for ledger data including the hash value, the time information, the timestamp token issued for the electronic data, and a fuzzy hash value of the electronic data from the specific timestamp issuing apparatus; and
acquiring the timestamp token issued for the ledger data from the specific timestamp issuing apparatus.