A method for identifying the authenticity of red printing ink fingerprints on documents

Abstract

The application discloses a method for identifying the authenticity of red printing oil fingerprints on documents. The method comprises the following steps: performing X-ray spectrum analysis on red printing oil lines in red printing oil fingerprints on the document to be identified; when characteristic peaks of handprint substances exist in the spectrum, it is determined that the red printing oil fingerprints are authentic; the characteristic peaks of the handprint substances include characteristic peaks of K and Na. The application provides a new method for identifying red printing oil fingerprints on documents, specifically uses scanning electron microscope (SEM) imaging technology and X-ray spectrum analysis technology to perform component testing on red printing oil fingerprints on documents; when the red printing oil fingerprints contain K, Na and Cl, which are main inorganic component elements, the distribution of the component elements can be determined as authentic red printing oil fingerprints; the method can identify the authenticity of red printing oil fingerprints and can realize nondestructive analysis.

Description

Technical Field

[0001] This invention relates to a method for identifying the authenticity of red ink fingerprints on documents, belonging to the field of fingerprint examination in forensic science. Background Technology

[0002] Currently, with the rapid advancement of technology, especially 3D printing and electronic seal technology, new forms of fingerprint-related crimes are constantly emerging, the most representative and urgently needing identification being forged fingerprints. In recent years, forged fingerprints have increasingly appeared in criminal cases such as fraud and civil economic disputes. For example, using another person's real fingerprint to create fingerprint seals or fingerprint films, and then forging fingerprints on forged documents to obtain illegal profits, is a concrete manifestation of the technological sophistication and high level of intelligence in criminal methods, posing a serious challenge to forensic science and technology.

[0003] As early as 2001, Geller et al. surveyed 152 forensic professionals, finding that 85% were aware of the possibility of forged fingerprints, 57% indicated that forged fingerprints posed a certain threat, and 45% admitted they could not distinguish between genuine and forged fingerprints. In 2014, Champod and Espinoza studied the risks posed by forged fingerprints, finding that approximately 53% of professionals mistook forged fingerprints for genuine ones, and approximately 45% mistook genuine fingerprints for forged ones. Therefore, researching methods for identifying the authenticity of fingerprints and improving fingerprint authentication capabilities is urgently needed.

[0004] Current research on fingerprint authentication mainly focuses on two aspects: first, traditional morphological comparison methods, which utilize advanced instruments and equipment to observe and analyze the appearance of genuine and counterfeit fingerprints, looking for differences in features such as ink accumulation, white space, edge features, details, and variations as the basis for authentication; second, deep learning recognition methods, which mainly use deep learning methods to process fingerprint images, improve the computational speed and accuracy of the method model, and achieve the distinction between genuine and counterfeit fingerprints. Overall, there is still a lack of scientific, effective, mature, and stable methods for authenticating fingerprints, especially for distinguishing genuine and counterfeit red ink fingerprints on documents. Solving these difficult problems has become a new direction for research. The genuine red ink fingerprint in the text includes both ink and fingerprint material, while counterfeit red ink fingerprints lack fingerprint material. However, the composition of fingerprint material is complex, mainly including sweat components (or simultaneously containing exogenous substances). Sweat components include water, inorganic matter, and organic matter, with water accounting for 98%-99.6%. Inorganic matter consists of cations and anions. Cations include more than twenty kinds such as sodium, potassium, calcium, magnesium, iron, silicon, aluminum, zinc, chromium, copper, manganese, nickel, and lead. Anions include chloride, bicarbonate, phosphate, and sulfate. Organic matter mainly consists of various amino acids, such as more than ten kinds such as threonine, tryptophan, serine, glycine, leucine, alanine, phenylalanine, isoleucine, proline, and tyrosine. The main elements of red ink are carbon, oxygen, nitrogen, silicon, aluminum, calcium, and zinc. The complexity of the composition has brought great difficulties to the identification of genuine and counterfeit red ink fingerprints on documents. Summary of the Invention

[0005] The purpose of this invention is to provide a method for identifying the authenticity of red ink fingerprints on documents, which can provide technical support for court trials. Based on the different types of material elements in genuine and counterfeit red ink fingerprints on documents—genuine fingerprints contain both fingerprint material and ink material, while counterfeit ink contains only ink material and no fingerprint material—scanning electron microscopy (SEM) imaging technology and X-ray energy dispersive spectroscopy (EDS) technology are used to examine the composition of red ink fingerprints on documents. By comparing and analyzing the distribution of component elements, the authenticity of red ink fingerprints can be identified.

[0006] The present invention provides a method for identifying the authenticity of red ink fingerprints on documents, comprising the following steps:

[0007] X-ray energy dispersive spectroscopy analysis was performed on the position of the red ink lines in the red ink fingerprint on the document to be identified. When the characteristic peaks of the fingerprint substance are present in the spectrum, it is determined to be a genuine red ink fingerprint. The characteristic peaks of the fingerprint substance include the characteristic peaks of K and Na.

[0008] In the aforementioned method for verifying the authenticity of red ink fingerprints on documents, conversely, if the fingerprint does not exhibit characteristic peaks as described, it is determined to be a counterfeit red ink fingerprint. That is, if the characteristic peaks of the fingerprint substance are not present in the spectral image, it is determined to be a counterfeit red ink fingerprint.

[0009] In the above method for identifying the authenticity of red ink fingerprints on documents, the characteristic peaks of the fingerprint substance further include characteristic peaks of K, Na, and Cl.

[0010] In the aforementioned method for verifying the authenticity of red ink fingerprints on documents, conversely, if the fingerprint does not exhibit the characteristic peaks of K, Na, and Cl, it is determined to be a counterfeit red ink fingerprint. That is, if the spectrum does not contain characteristic peaks of K, Na, and Cl, or only contains the characteristic peak of Cl, it is determined to be a counterfeit red ink fingerprint.

[0011] Furthermore, in the above-mentioned method for identifying the authenticity of red ink fingerprints on documents, when the spectrum contains characteristic peaks including C, O, Ca, K, Na, and Cl, it is determined to be an authentic red ink fingerprint.

[0012] In the aforementioned method for verifying the authenticity of red ink fingerprints on documents, conversely, if the fingerprint does not meet certain criteria, it is determined to be a counterfeit red ink fingerprint. That is, if the spectrum contains characteristic peaks including C, O, and Ca but not K and Na, or contains characteristic peaks including C, O, Ca, and Cl but not K and Na, it is determined to be a counterfeit red ink fingerprint.

[0013] In the above method for identifying the authenticity of red ink fingerprints on documents, the red ink fingerprints on the documents to be identified must have been present for at least 72 hours.

[0014] In the above method for verifying the authenticity of red ink fingerprints on documents, the X-ray energy dispersive spectroscopy (EDS) is combined with a scanning electron microscope (SEM). Before the EDS, the analysis position is located at the red ink lines using an optical mode. As an example, the EDS uses a Phenom XL desktop SEM (Phenom World, Netherlands) and an Amptek Fast SDDX123 X-ray energy dispersive spectroscopy analyzer.

[0015] In the above method for identifying the authenticity of red ink fingerprints on documents, the conditions for X-ray energy spectrum analysis are as follows: point analysis mode, voltage 15-10KV, backscattered electron detector imaging, medium-high vacuum 10Pa, 300-20000x mode.

[0016] In one embodiment of the present invention, the conditions for X-ray energy spectrum analysis are as follows: point analysis mode, voltage 15KV or 10KV, backscattered electron detector imaging, medium-high vacuum 10Pa, 1000x mode; when the characteristic peaks of the spectrum are characteristic peaks of C, O, Ca, K, Na and Cl, it is determined to be a genuine red ink fingerprint.

[0017] Conversely, if the characteristic peaks of the spectrum are C, O, or Ca, it is determined to be a counterfeit red ink fingerprint.

[0018] In another embodiment of the present invention, the conditions for X-ray energy spectrum analysis are as follows: point analysis mode, voltage 15KV or 10KV, backscattered electron detector imaging, medium-high vacuum 10Pa, 10000x mode; when the characteristic peaks of the spectrum are characteristic peaks of C, O, Ca, K, Na, Cl and Si, it is determined to be a genuine red ink fingerprint.

[0019] Conversely, if the characteristic peaks of the spectrum are those of C, O, Ca, Mg, Cl, and S, it is determined to be a counterfeit red ink fingerprint.

[0020] In the above-mentioned method for verifying the authenticity of red ink fingerprints on documents, the forged red ink fingerprints are made from a fingerprint mold (such as a stamp or imprint film) created from an electronic image of the fingerprint.

[0021] In the above-mentioned method for verifying the authenticity of red ink fingerprints on documents, the paper used for the documents is writing paper, printing paper, or photocopying paper.

[0022] In the above-described method for verifying the authenticity of red ink fingerprints on documents, the type of red ink is not limited. In a specific embodiment of the present invention, the red ink used is the Qixing brand quick-drying atomic ink pad QX-302 produced by Hengshui Qixing Stationery Co., Ltd.

[0023] The present invention has the following beneficial effects:

[0024] This invention provides a novel method for authenticating red ink fingerprints on documents. Specifically, it utilizes scanning electron microscopy (SEM) imaging technology and X-ray energy dispersive spectroscopy (EDS) to examine the composition of the red ink lines in the fingerprint. When the red ink fingerprint contains inorganic elements, primarily K, Na, and Cl, it can be determined to be an authentic red ink fingerprint. When no inorganic elements, primarily K, Na, and Cl, are observed in the red ink fingerprint, it can be determined to be a counterfeit red ink fingerprint. This method enables the identification of genuine and counterfeit red ink fingerprints and allows for non-destructive analysis. Attached Figure Description

[0025] Figure 1 In Example 1 of this invention, 72 hours after the formation of the real red ink fingerprint, a fingerprint sample containing part of the red ink lines was cut out as a test sample.

[0026] Figure 2The image shows the results of elemental analysis of the red ink fingerprints on the sample in Example 1 of this invention, using scanning electron microscopy (SEM) imaging technology and X-ray energy dispersive spectroscopy (EDS) analysis technology.

[0027] Figure 3 In Example 1 of this invention, 72 hours after the fake red ink fingerprint was formed, a fingerprint sample containing part of the red ink lines was cut off and used as a test sample.

[0028] Figure 4 The image shows the results of elemental analysis at the ridge positions of the sample to be tested using scanning electron microscopy (SEM) imaging technology and X-ray energy dispersive spectroscopy (EDS) technology, which is used to analyze the fake red ink fingerprint in Example 1 of this invention.

[0029] Figure 5 The image shows the results of elemental analysis of the red ink fingerprints on the sample in Example 2 of this invention, using scanning electron microscopy (SEM) imaging technology and X-ray energy dispersive spectroscopy (EDS) analysis technology.

[0030] Figure 6 The image shows the results of elemental analysis at the location of the red ink mark in the sample to be tested in Example 2 of this invention, using scanning electron microscopy (SEM) imaging technology and X-ray energy dispersive spectroscopy (EDS).

[0031] Figure 7 The image shows the results of elemental analysis of the small furrows (the blank area between the red ink lines in the background) in the sample to be tested, using scanning electron microscopy (SEM) imaging technology and X-ray energy dispersive spectroscopy (EDS) technology, for the actual red ink fingerprint sample in Comparative Example 1 of this invention. Detailed Implementation

[0032] As mentioned in the background section, the complexity of the composition of fingerprint material and red ink makes the identification of genuine and counterfeit red ink extremely difficult. In view of this, the present invention provides a method for identifying the authenticity of red ink fingerprints on documents, comprising the following steps: performing X-ray energy dispersive spectroscopy analysis on the red ink lines in the red ink fingerprint on the document to be identified; when the characteristic peaks of fingerprint material are present in the spectrum, it is determined to be a genuine red ink fingerprint; the characteristic peaks of fingerprint material include characteristic peaks of K and Na.

[0033] The authentic red ink fingerprint on documents involved in this invention refers to a finger with red ink on it that comes into contact with the paper surface under the action of force and then leaves, leaving behind an authentic red ink fingerprint. Its material composition is mainly ink and fingerprint secretions from the finger. The forged red ink fingerprint on documents involved in this invention refers to a fingerprint stamp or stamp with red ink on it that comes into contact with the paper surface under the action of force and then leaves behind a forged red ink fingerprint. The fingerprint material left behind consists only of ink and no fingerprint material.

[0034] The scanning electron microscopy (SEM) imaging technology involved in this invention specifically refers to the use of a scanning electron microscope, where an electron beam scans onto the sample surface, obtaining a large number of physical signals. The intensity of these signals is related to the surface characteristics of the sample, and they are then converted into video signals in a specific manner, amplified, and used to form a scanning electron image. The X-ray energy dispersive spectroscopy (EDS) technology involved in this invention specifically employs an X-ray energy dispersive spectrometer, where an electron beam interacts with the near-surface region of the sample, generating a large number of physical signals. Characteristic X-ray spectral peaks are obtained from these signals, from which qualitative and quantitative information about the elements on the surface of the observed sample can be obtained.

[0035] X-ray energy dispersive spectroscopy analysis was performed on the positions of the red ink lines in genuine and counterfeit red ink fingerprints. The results showed that the authenticity of a red ink fingerprint can be determined by observing whether characteristic peaks of K and Na are present simultaneously in the spectrum.

[0036] It is understood that, depending on the detection conditions, the characteristic peaks of fingerprint substances may also include characteristic peaks of other fingerprint substance components. Furthermore, the characteristic peaks of the fingerprint substance include characteristic peaks of K, Na, and Cl. Unlike other elemental analysis methods, this invention employs scanning electron microscopy (SEM) imaging technology and X-ray energy dispersive spectroscopy (EDS) technology. The red fingerprint to be tested is placed in the working chamber of the SEM for observation and analysis, thereby generating an electronic image and elemental distribution result map. By judging whether the elemental distribution result contains inorganic substances (sweat components) mainly composed of K, Na, and Cl, it is determined whether it is a fingerprint sweat substance, ultimately achieving effective identification of genuine and fake fingerprints.

[0037] Understandably, the spectrum also contains characteristic peaks of the ink substance. Furthermore, when the spectrum contains characteristic peaks including C, O, Ca, K, Na, and Cl, it is determined to be a genuine red ink fingerprint.

[0038] According to the present invention, the conditions for X-ray energy dispersive spectroscopy analysis are as follows: point analysis mode, voltage 15–10 kV (e.g., 15 kV), backscattered electron detector imaging, medium-high vacuum 10 Pa, 300–20000x mode (e.g., 1000–10000x, 1000x, or 10000x). In this invention, the voltage and amplification factor in the X-ray energy dispersive spectroscopy analysis can be adjusted within the above ranges. It is understood that as the amplification factor changes in the X-ray energy dispersive spectroscopy analysis, the types and number of characteristic peaks will also change, but this does not affect the identification of the authenticity of the red ink fingerprint based on the characteristic peaks of the fingerprint material.

[0039] The present invention will now be described in further detail with reference to specific embodiments. The given embodiments are merely illustrative of the invention and not intended to limit its scope. The embodiments provided below can serve as a guide for further improvements by those skilled in the art and do not constitute a limitation on the invention in any way.

[0040] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; and the materials and reagents used are commercially available unless otherwise specified.

[0041] The red ink used in the following examples is Qixing brand quick-drying atomic ink pad (QX-302), with the product name being quick-drying atomic ink pad and the product number being QX-302 (manufacturer: Hengshui Qixing Stationery Co., Ltd.).

[0042] The scanning electron microscope / energy dispersive spectrometer used in the following examples is a Phenom XL desktop scanning electron microscope (PhenomWorld, Netherlands) and an X-ray energy dispersive spectrometer (Amptek Fast SDDX123, USA).

[0043] Example 1: Identification of the authenticity of red ink fingerprints on documents

[0044] 1. Analysis of genuine red ink fingerprints

[0045] Authentic red ink fingerprints were examined using scanning electron microscopy / energy dispersive spectroscopy 72 hours after formation. The specific steps are as follows:

[0046] On ordinary A4 paper, a normal fingerprint is formed by pressing the paper, creating a genuine red ink fingerprint. After being left to stand naturally for 72 hours, a fingerprint sample containing some red ink lines is cut out (1.2cm long and 0.3cm wide). Figure 1As shown in the image, the sample was fixed to the scanning electron microscope (SEM) stage with conductive adhesive. The stage was then placed inside the working chamber. Following the operating procedures for the SEM and energy dispersive spectroscopy (EDS), the location of the red ink line was positioned using optical mode. The electronic mode was then switched, and the parameters were selected: voltage 15 kV, BSD, medium-high vacuum (10 Pa), and 1000x magnification. Once the sample surface was clear, point analysis mode EDS was performed to obtain the EDS spectrum (as shown in the image). Figure 2 As shown in the figure, the elemental distribution characteristics of the surface of the sample to be observed can be obtained, specifically the elements such as C, Cl, Na, O, K, and Ca.

[0047] 2. Analysis of counterfeit red ink fingerprints

[0048] The counterfeit red ink fingerprint was examined using a scanning electron microscope / energy dispersive spectroscopy (EDS) 72 hours after it was formed. The specific steps are as follows:

[0049] On ordinary A4 paper, a fake fingerprint is created by forging a red ink fingerprint (the fingerprint image is extracted electronically, a fingerprint stamp is made using electronic stamp technology, red ink is applied, and then the stamp is applied to the paper). After being left to stand naturally for 72 hours, a fingerprint sample containing partial red ink lines is cut (1.2cm long, 0.3cm wide). Figure 3 As shown in the image, the sample was fixed to the scanning electron microscope (SEM) stage with conductive adhesive. The stage was then placed inside the working chamber. Following the operating procedures for the SEM and energy dispersive spectroscopy (EDS), the location of the red ink line was positioned using optical mode. The electronic mode was then switched, selecting 15kV, BSD, medium-high vacuum (10Pa), and 1000x magnification. A point analysis mode EDS was performed on the surface to obtain the EDS spectrum (as shown in the image). Figure 4 As shown in the figure, the elemental distribution characteristics of the sample surface can be obtained, which are elements such as C, O, and Ca.

[0050] As can be seen from the above energy spectrum, genuine red ink fingerprints not only contain elements such as C, O, and Ca, but also show characteristic peaks representing sweat substances (such as inorganic salts like NaCl and KCl), indicating that they contain fingerprint sweat substances, thus identifying them as genuine red ink fingerprints. Counterfeit red ink fingerprints only contain elements such as C, O, and Ca, and do not show characteristic peaks representing sweat substances, indicating that they do not contain fingerprint sweat substances, thus identifying them as counterfeit red ink fingerprints, ultimately achieving effective identification.

[0051] Example 2

[0052] Same as Example 1, except the magnification was adjusted to 10000x, with all other steps remaining unchanged. The experimental results are as follows:

[0053] Energy spectrum of a genuine red ink fingerprint (e.g.) Figure 5As shown in the figure, the elemental distribution characteristics of the surface of the sample to be observed can be obtained, specifically the elements such as C, Cl, Na, O, K, Ca, and Si.

[0054] Energy spectrum of counterfeit red ink fingerprints (e.g.) Figure 6 As shown in the figure, the elemental distribution characteristics of the surface of the sample to be observed can be obtained, specifically the elements such as C, O, Ca, Mg, Cl, and S.

[0055] Comparative Example 1

[0056] Similar to Example 1, the analysis of a real red ink fingerprint was performed. The difference was that the background area in the middle of the red ink lines was located using an optical mode. The remaining steps were the same, and the obtained energy spectrum is shown below. Figure 7 As shown, the elemental distribution characteristics of the sample surface can be obtained, which are elements such as C, O, and Ca, and the results are the same at different background locations.

[0057] Comparing Example 1 and Comparative Example 1, it was found that X-ray energy dispersive spectroscopy analysis of the background area in the middle of the red ink line at the small furrow position showed the same elemental distribution characteristics as the counterfeit red ink fingerprint, which consisted of elements such as C, O, and Ca. Therefore, it is impossible to distinguish the authenticity of the red ink fingerprint by performing X-ray energy dispersive spectroscopy analysis on the background area in the middle of the red ink line at the small furrow position in the document.

[0058] Therefore, the present invention uses X-ray energy dispersive spectroscopy to analyze the position of the red ink lines in the red ink fingerprint on the document to be identified, and the authenticity of the red ink fingerprint can be identified based on the presence of characteristic peaks of K and Na or characteristic peaks of K, Na and Cl in the spectrum.

[0059] The present invention has been described in detail above. Those skilled in the art will recognize that the invention can be practiced in a wide range of ways without departing from its spirit and scope. While specific embodiments have been provided, it should be understood that further modifications can be made to the invention. In summary, according to the principles of the invention, this application is intended to include any changes, uses, or improvements to the invention, including changes made using conventional techniques known in the art that depart from the scope disclosed herein.

Claims

1. A method for identifying the authenticity of red printing ink fingerprints on documents, comprising the following steps: X-ray energy spectrum analysis is performed on the red printing ink lines in the red printing ink fingerprints on the documents to be identified, and when characteristic peaks of handprint substances are present in the spectrum, the red printing ink fingerprints are determined to be authentic; the characteristic peaks of the handprint substances include characteristic peaks of K and Na; The X-ray energy spectrum analysis is combined with a scanning electron microscope, and the analysis position is located at the red printing ink lines by optical mode before the X-ray energy spectrum analysis; The X-ray energy spectrum analysis is performed under the following conditions: point analysis mode, voltage of 15-10 KV, backscattered electron detector imaging, medium-high vacuum of 10 Pa, and 1000-10000 times mode; The document paper is writing paper, printing paper or printed paper.

2. The method of authenticating the genuineness of red stamp ink fingerprints on documents as claimed in claim 1, wherein: The characteristic peaks of the handprint substances include characteristic peaks of K, Na and Cl.

3. The method of authenticating the genuineness of red stamp ink fingerprints on documents as claimed in claim 1 wherein: When characteristic peaks of C, O, Ca, K, Na and Cl are present in the spectrum, the red printing ink fingerprints are determined to be authentic.

4. The method of authenticating the identity of a red stamp ink print on a document according to any one of claims 1-3, characterized in that: The red printing ink fingerprints on the documents to be identified are left for more than or equal to 72 hours.

5. The method of authenticating the genuineness of red stamp ink fingerprints on documents as claimed in claim 1 wherein: The X-ray energy spectrum analysis is performed under the following conditions: point analysis mode, voltage of 15 KV or 10 KV, backscattered electron detector imaging, medium-high vacuum of 10 Pa, and 1000 times mode; and when characteristic peaks of C, O, Ca, K, Na and Cl are present in the spectrum, the red printing ink fingerprints are determined to be authentic.

6. The method of authenticating the genuineness of red stamp ink fingerprints on documents as claimed in claim 1 wherein: The X-ray energy spectrum analysis is performed under the following conditions: point analysis mode, voltage of 15 KV or 10 KV, backscattered electron detector imaging, medium-high vacuum of 10 Pa, and 10000 times mode; and when characteristic peaks of C, O, Ca, K, Na, Cl and Si are present in the spectrum, the red printing ink fingerprints are determined to be authentic.

7. The method of authenticating the identity of a red stamp ink print on a document according to any one of claims 1-3, wherein: The counterfeit red printing ink fingerprints are made by a handprint mold made from a handprint electronic image.

Images