| CPC H04L 9/3247 (2013.01) [G06F 16/152 (2019.01); H04L 9/3239 (2013.01); H04L 9/50 (2022.05)] | 16 Claims |
|
1. A method of securing a given original digital file belonging to a batch of a plurality of original digital files against forgery or tampering, each original digital file including its own digital data, comprising the steps of:
for each original digital file of the batch, calculating by means of a one-way function an associated digital file signature of its digital data;
forming a tree based on the plurality of calculated digital file signatures for the original digital files of the batch and comprising nodes arranged according to a given nodes ordering in the tree, the tree comprising node levels from the leaf nodes, corresponding to the plurality of digital file signatures respectively associated to the plurality of original digital files in the batch, to the root node of the tree, every non-leaf node of the tree corresponding to a digital signature by means of the one-way function of a concatenation of the respective digital signatures of its child nodes according to a tree concatenation ordering, the root node corresponding to a reference root digital signature, wherein the root digital signature is generated by means of the one-way function of a concatenation of the digital signatures of the nodes of a penultimate nodes level in the tree according to the tree concatenation ordering;
associating with the given original digital file a corresponding digital verification key being a sequence of the respective digital signatures, from the leaf nodes level to the penultimate nodes level, of every other leaf node having the same parent node in the tree that the leaf-node corresponding to the digital file signature of the given original digital file, and successively at each next level in the tree, of every non-leaf node having the same parent node in the tree that the previous same parent node considered at the preceding level;
making available to a user the reference root digital signature of the tree; and
including in the given original digital file a corresponding machine readable digital security marking including a two-dimensional barcode comprising a representation of its digital data and its corresponding digital verification key,
thereby obtaining a marked original digital file of which digital data are secured against forgery or tampering,
wherein the digital data of the marked original digital file include reference characteristic digital data of a corresponding unique physical characteristic of an associated object or individual; and
delivering an indication that the digital file is genuine or fake in response to a digital signature verification of the digital file, and enabling a computer system to perform a predetermined action.
|