US 11,924,342 B2
Computer-implemented methods for evidencing the existence of a digital document, anonymously evidencing the existence of a digital document, and verifying the data integrity of a digital document
Johnson Zone An Kong, Tai Po (HK); Michael Ming-Jae Lin, Pok Fu Lam (HK); and Wei Hsiung Nicolas Yang, Hong Kong (HK)
Assigned to 707 Limited, Central District (HK)
Filed by 707 Limited, Central (HK)
Filed on Nov. 15, 2021, as Appl. No. 17/526,161.
Application 17/526,161 is a continuation in part of application No. 16/622,824, granted, now 11,177,940, previously published as PCT/CN2018/091833, filed on Jun. 19, 2018.
Claims priority of application No. 17106138.1 (HK), filed on Jun. 20, 2017.
Prior Publication US 2022/0078008 A1, Mar. 10, 2022
Int. Cl. H04L 9/08 (2006.01); G06F 21/64 (2013.01); H04L 9/32 (2006.01)
CPC H04L 9/0872 (2013.01) [G06F 21/645 (2013.01); H04L 9/0894 (2013.01); H04L 9/321 (2013.01); H04L 9/3236 (2013.01); H04L 9/3297 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A computer-implemented method for evidencing the existence of a digital document comprising the steps of:
A. obtaining metadata of a digital document in a user's system;
B. obtaining a cryptographic hash of the digital document via the user's system;
C. sending the metadata and the cryptographic hash from the user's system to a remote device; or sending the metadata and the cryptographic hash to the remote device over the internet;
D. receiving the metadata and the cryptographic hash at the remote device;
E. requesting a time stamp from a time source;
F. receiving the time stamp at the remote device from the time source, wherein the remote device does not comprise the time source, and wherein the time stamp is based upon the time that the remote device receives the metadata and the cryptographic hash;
E. combining the metadata, the cryptographic hash, and the time stamp in an evidence key generator to generate an evidence key;
F. storing the evidence key to provide a stored evidence key;
G. generating a further cryptographic hash of the evidence key in a further evidence key generator to form a further evidence key; and
H. storing the further evidence key to form a stored further evidence key,
wherein during the method the digital document remains within the user's system.