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EP0268450A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Authentication methods and systems

Assignee: Light Signatures Inc
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Filing: 1987-11-16
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Granted: —
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Expires: 2007-11-16
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Abstract

Abstract The authenticity of a document (D) is tested by sensing (14) its translucency throughout an area (12) and correlating the sequence of representations (20 Figure 2) produced, with a sequence of reference representations (18 Figure 2) read (16) from a magnetic recording (10) of an earlier-made sensing. Correlation is carried out by relating successive overlapping parts (L Figure 2) of the freshly-derived and digitized sequence with corresponding overlapping parts (L) respectively, of the digitized reference sequence. The overlapping parts (L) are of the same length (N), and overlap with one another equally, throughout both sequences (20,18), the extent (M) of overlap being such that all individual representations in each sequence (20;18) occur in three successive parts of that respective sequence. Assembler circuits (44,46; Figure 1) supply signals (SUM R, SUM R², SUM RS) in accordance with functions of the successive parts (S;R) of the two sequences, to an arithmetic unit (50) for generation of correlation scores (C) that are then analyzed (56) to produce an indication (42) of the degree of authenticity. A preliminary, independent check on the maxima, minima, and/or average value of the freshly-­derived sequence is carried out by a test unit (38) to signal rejection of the document (D) if the check is not satisfied.

Inventors

  • 👤 David Gene Gold
  • 👤 Vahakn Kevork Gharibian

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-30 13:00
CPC Classifications
G; G07; G07F; G07F7/00; G07F7/08; G07F7/086; G06; G06K; G06K19/00; G06K19/06; G06K19/08; G06K19/10; G06K19/14; G06Q; G06Q20/00; G06Q20/30; G06Q20/34; G06Q20/347; G06Q20/38; G06Q20/40; G06Q20/409; G07D; G07D7/00; G07D7/004; G07D7/0047; G07D7/20

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 101 words
A method of authentication of a document or other item (D), in which a sequence of representations (20;S) freshly derived from sensing the item (D) is compared with a sequence of reference representations (18;R) registered in respect of such item, characterised in that successive, overlapping parts (L) of the sequence of freshly-derived representations (20;S) are correlated respectively with successive, overlapping parts (L) of the sequence of reference representations (18;R), that values (C) for the extents of correlation between the said parts correlated, are derived, and that authentication of said item (D) is provided in dependence upon the derived correlation values (C).
Claim 2
Independent Claim 101 words
A method of authentication of a document or other item (D), in which a sequence of representations (20;S) freshly derived from sensing the item (D) is compared with a sequence of reference representations (18;R) registered in respect of such item, characterised in that successive, overlapping parts (L) of the sequence of freshly-derived representations (20;S) are correlated respectively with successive, overlapping parts (L) of the sequence of reference representations (18;R), that values (C) for the extents of correlation between the said parts correlated, are derived, and that authentication of said item (D) is provided in dependence upon the derived correlation values (C).
Claim 3
Dependent Claim 54 words
A method according to Claim 1 characterised in that the parts (L) of the sequences of freshly-derived and reference representations (20,18;S,R) used in the correlation operation are all substantially of the same length (N) as one another, and that the extent (M) of overlap between them is the same substantially throughout both sequences (20,18;S,R).
Claim 4
Dependent Claim 51 words
A method according to Claim 1 or Claim 2 characterised in that the extent (M) of overlap between successive parts (L) of each sequence of representations (20,18;S,R) used in the correlation operation, is such that substantially all individual representations (S1-SN,R1-RN) occur in three such successive parts (L) of the respective sequence.
Claim 5
Independent Claim 21 words
A method according to any one of Claims 1 to 3 characterised in that both sequences (20,18;S,R) are of digital data.
Claim 6
Independent Claim 39 words
A method according to any one of Claims 1 to 4 characterised in that the sequence of reference representations (18;R) is read from a record (10) of that sequence borne by the said document or other item (D) itself.
Claim 7
Independent Claim 35 words
A method according to any one of Claims 1 to 5 characterised in that the sequence of freshly-derived representations (20;S) is submitted to an authentication test (38) separately from, and additional to, the correlation operation.
Claim 8
Independent Claim 39 words
A method according to any one of Claims 1 to 6 characterised in that the correlation values are computed as multi-valued scores (C), and that an output indication (42) of authenticity is derived by analysis (56) of these scores.
Claim 9
Independent Claim 121 words
A system for authentication of a document or other item (D), in which a sequence of representations (20;S) freshly derived from sensing the item (D) is compared with a sequence of reference representations (18;R) registered in respect of such item, and an output (42) related to authenticity of said item (D) is provided in dependence upon the result of the comparison, characterised in that the system includes means (44,46,50) for correlating successive, overlapping parts (L) of the sequence of freshly-­derived representations (20;S) respectively with successive, overlapping parts (L) of the sequence of reference representations (18;R) to derive values (C) for the extents of correlation between them, and that the said output (42) is provided in dependence upon the correlation values (C).
Claim 10
Independent Claim 121 words
A system for authentication of a document or other item (D), in which a sequence of representations (20;S) freshly derived from sensing the item (D) is compared with a sequence of reference representations (18;R) registered in respect of such item, and an output (42) related to authenticity of said item (D) is provided in dependence upon the result of the comparison, characterised in that the system includes means (44,46,50) for correlating successive, overlapping parts (L) of the sequence of freshly-­derived representations (20;S) respectively with successive, overlapping parts (L) of the sequence of reference representations (18;R) to derive values (C) for the extents of correlation between them, and that the said output (42) is provided in dependence upon the correlation values (C).
Claim 11
Dependent Claim 51 words
A system according to Claim 8 characterised in that the parts (L) of the freshly-derived and reference representations (20,18;S,R) used in the correlation operation are all substantially of the same length (N) as one another, and that the extent (M) of overlap between them is the same substantially throughout both sequences.
Claim 12
Dependent Claim 51 words
A system according to Claim 8 or Claim 9 characterised in that the extent (M) of overlap between successive parts (L) of each sequence of representations (20,18;S,R) used in the correlation operation, is such that substantially all individual representations (S1-SN,R1-RN) occur in three such successive parts (L) of the respective sequence.
Claim 13
Independent Claim 21 words
A system according to any one of Claims 8 to 10 characterised in that both sequences (S,R) are of digital data.
Claim 14
Independent Claim 94 words
A system according to any one of Claims 8 to 11 characterised in that the system includes means (44,46) for deriving from the sequences of freshly-­derived and reference representations (20,18;S,R) a plurality of signals in accordance with respective arithmetical functions (SUM R,SUM R²,SUM RS) of the said representations of the two sequences (20,18;S,R), each such function being a function of the representation-magnitudes within the successive parts (L) of one or both of the said sequences (20,18;S,R), and arithmetic means (50) responsive to these signals to compute the said correlation values as multi-valued scores (C).
Claim 15
Dependent Claim 31 words
A system according to Claim 12 characterised in that the system includes means (56) for processing the correlation scores (C) to provide said output as representative of degree of authenticity (42).
Claim 16
Independent Claim 35 words
A system according to any one of Claims 8 to 13 characterised in that the system also includes means (38) for analyzing the representation-magnitudes of the freshly-derived sequence (20,S) as an additional test of authenticity.

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