Patent EP0286378A2 successfully refreshed from Google Patents.
EP0286378A2
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Authenticating methods and systems
Assignee: Light Signatures Inc
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Filing: 1988-04-06
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Granted: —
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Expires: 2008-04-06
Abstract
Abstract Authenticity of a paper document (10) is tested by sensing (40) its transparency and comparing (32) the sequence of representations produced, with a sequence of reference representations read (39) from a record of an earlier-made sensing written (38) on the document (10) in an offset-printed (and therefore non-uniform) magnetic stripe (18). The reference sequence is written on the stripe (18) in the form of an encrypted identifier (156, Figure 4) within a bit string (Figure 4) that is interspersed with framing characters (155) and includes a public encryption key (158) and an error-correction code (162). Each data and control bit of the bit-string format is written as an eight-bit character enabling ready distinction between data and control bits and enhancing error detection and correction of the string when read (39) from the non-uniform stripe (18); the relative timings and the polarities of peaks of the analogue signal from the magnetic reading head 939) determine the data value ("0" or "1" according to timing interval t or t/2) or the control nature (interval 3t/2) or each read bit. The error-correction code is applied to reduce errors and enable decryption of the recorded identifier using the public key, whereby an appropriate degree of correlation for authenticity confirmation, can be achieved with the fresh transparency output (40).
Inventors
- 👤 Frank Dan Tucker
- 👤 Leonard Nunley
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 14:30
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/30; H04L9/304; G; G06; G06K; G06K19/00; G06K19/06; G06K19/08; G06K19/10; G06K19/14; G07; G07D; G07D7/00; G07D7/004; G07D7/04; G07D7/20
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
113 words
A method for authenticating a document or other item (10), in which a sequence of representations freshly derived from sensing (40) the item (10) is compared (32) with a sequence of reference representations registered on the item (10), characterised in that the sequence of reference representations is a bit string (149, Figure 4) recorded in magnetic material (18) of the item (10), that the recorded bit string (149) is read out from the magnetic material (18), and that the bit string as read out (300, Figure 8) is processed (32,42) to detect errors therein and to correct for at least some of the errors detected, before comparison with the freshly-derived representations is made.
Claim 2
Independent Claim
113 words
A method for authenticating a document or other item (10), in which a sequence of representations freshly derived from sensing (40) the item (10) is compared (32) with a sequence of reference representations registered on the item (10), characterised in that the sequence of reference representations is a bit string (149, Figure 4) recorded in magnetic material (18) of the item (10), that the recorded bit string (149) is read out from the magnetic material (18), and that the bit string as read out (300, Figure 8) is processed (32,42) to detect errors therein and to correct for at least some of the errors detected, before comparison with the freshly-derived representations is made.
Claim 3
Dependent Claim
34 words
A method according to Claim 1 characterised in that the bit string (149) is recorded in encrypted form and the processing (32,42) of the bit string as read out includes a step of decryption.
Claim 4
Dependent Claim
31 words
A method according to Claim 2 characterised in that a key (158, Figure 4) used in the step of decryption is read out from the magnetic material with the bit string.
Claim 5
Independent Claim
47 words
A method according to any one of Claims 1 to 3 characterised in that the processing of the bit string (300) includes a step of assigning data values to bits of the string in dependence upon relative timings of signal-peaks read out from the magnetic material (18).
Claim 6
Independent Claim
97 words
A method according to any one of Claims 1 to 4 characterised in that reading of the bit string from the magnetic material (18) includes the step of detecting magnetic flux changes in the magnetic material to derive an analogue signal (300) dependent on the flux changes, that the relative timings of peaks in the amplitude of the analogue signal (300) are determined, and that the processing of the bit string includes assigning data values to bits of the string according to the peak-polarities and the detected relative timings of the peaks in the analogue signal (300).
Claim 7
Dependent Claim
46 words
A method according to Claim 4 or Claim 5 characterised in that the time interval between successive peaks determines whether the data value '0' or '1' is assigned to the respective bit or the bit is treated otherwise than as a data bit of the sequence.
Claim 8
Dependent Claim
39 words
A method according to Claim 6 characterised in that the data value '0' or '1' is assigned to the respective bit in dependence upon whether the interval between successive peaks corresponds to a period of length t or t/2.
Claim 9
Dependent Claim
32 words
A method according to Claim 7 characterised in that the respective bit is assigned control-character status in the event that the interval between successive peaks corresponds to a period of length 3t/2.
Claim 10
Independent Claim
30 words
A method according to any one of Claims 1 to 8 characterised in that each bit value of the string is recorded as a plurality of bits (220 Figure 6B).
Claim 11
Independent Claim
40 words
A method according to any one of Claims 1 to 9 characterised that it includes the step of deriving a bit string by sensing the item (10) and recording this bit string on the item in the magnetic material (18)
Claim 12
Independent Claim
34 words
A method according to any one of Claims 1 to 10 characterised in that the item is a paper document (10) and that the magnetic material (18) is printed on the paper document (10).
Claim 13
Dependent Claim
20 words
A method according to Claim 11 characterised in that the printing of the magnetic material (18) is by offset printing.
Claim 14
Independent Claim
127 words
A system for authenticating a document or other item (10), in which a sequence of representations freshly derived from sensing (40) the item (10) is compared (32) with a sequence of reference representations registered on the item (10), and an output related to authenticity of the item (10) is provided in dependence upon the result of the comparison, characterised in that the system includes means (39) for reading the sequence of reference representations as a bit string (149, Figure 4) from magnetic material (18) of the item (10), and means (32,42) for submitting the bit string as read out (300, Figure 8) to a process for detecting errors therein and for correcting at least some of the errors detected, before comparison with the freshly-derived representations is made.
Claim 15
Independent Claim
127 words
A system for authenticating a document or other item (10), in which a sequence of representations freshly derived from sensing (40) the item (10) is compared (32) with a sequence of reference representations registered on the item (10), and an output related to authenticity of the item (10) is provided in dependence upon the result of the comparison, characterised in that the system includes means (39) for reading the sequence of reference representations as a bit string (149, Figure 4) from magnetic material (18) of the item (10), and means (32,42) for submitting the bit string as read out (300, Figure 8) to a process for detecting errors therein and for correcting at least some of the errors detected, before comparison with the freshly-derived representations is made.
Claim 16
Dependent Claim
35 words
A system according to Claim 13 characterised in that the bit string (149) is recorded in encrypted form on the item (10), and that the processing means (32,42) decrypts the bit string read out (300).
Claim 17
Dependent Claim
39 words
A system according to Claim 14 characterised in that a key (158, Figure 4) for decryption of the bit string read out (300), is derived from data (158) read out from the magnetic material (18) with the bit string.
Claim 18
Independent Claim
47 words
A system according to any one of Claims 13 to 15 characterised in that the processing means (32,42) detects the relative timings of signal-peaks read out from the magnetic material (18), and assign data values to bits of the string in dependence upon the detected relative timings.
Claim 19
Independent Claim
95 words
A system according to any one of Claims 13 to 16 characterised in that the means for reading the bit string from the magnetic material (18) detects magnetic flux changes in the magnetic material to derive an analogue signal (300) dependent on the flux changes, that the processing means (32,42) detects relative timings of peaks in the amplitude of the analogue signal (300), and that the processing means (32,42) assigns data values to bits of the bit string according to the peak-polarities and the detected relative timings of the peaks in the analogue signal. (300).
Claim 20
Dependent Claim
48 words
A system according to Claim 16 or Claim 17 characterised in that the processing means (32,42) detects the time intervals between successive peaks and in accordance therewith assigns the data value '0' or '1' to the respective bit or treats it as a non-data bit of the sequence.
Claim 21
Dependent Claim
39 words
A system according to Claim 18 characterised in that the data value '0' or '1' is assigned to the respective bit in dependence upon whether the interval between successive peaks corresponds to a period of length t or t/2.
Claim 22
Dependent Claim
32 words
A system according to Claim 19 characterised in that the respective bit is assigned control-character status in the event that the interval between successive peaks corresponds to a period of length 3t/2.
Claim 23
Independent Claim
30 words
A system according to any one of Claims 13 to 20 characterised in that each bit value of the string is recorded as a plurality of bits (220 Figure 6B).
Claim 24
Independent Claim
43 words
A system according to any one of Claims 13 to 21 characterised in that the system includes provision (38) for recording a bit string in the magnetic material (18) in accordance with a sequence of representations derived from sensing (40) the item (10).
Claim 25
Independent Claim
24 words
A method according to any one of Claims 13 to 23 characterised in that the printing of the magnetic material (18) is offset printing.
References Cited (Backward Citations)
No citation records indexed.
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