Automated detection and classification of counterfeit banknotes using quantitative features captured by spectral-domain optical coherence tomography

Counterfeiting of banknotes is still a severe crime problem in many countries. One of the most significant issue for solving the crime is to classify the counterfeit types and identify the sources. Most of the current methods to classify counterfeit banknotes rely on manual examination that is time-consuming and labor-intensive. Moreover, these methods only detect surface features which can be easily imitated through advanced printing technology. In this study, an automated method based on optical coherence tomography (OCT) and machine-learning algorithms was proposed to classify different types of banknotes based on the internal features. A spectral-domain OCT (SD-OCT) system was employed for sub-surface imaging and quantitative assessment of banknotes. A total of 29 Chinese 100-Yuan banknotes were collected, in which 4 of them were real and 25 of them were counterfeiting by three different printing processes. Each banknote was imaged 10 times in 3 distinct regions, which resulted in a dataset of 290 samples. Each sample was characterized by extracting 2 A-scan (OCT signal intensity along depth) based features and 14B-scan (cross-sectional OCT images) based features. Several machine-learning models, including logistic regression (LR), support vector machines (SVM), K-nearest neighbor (KNN) and random forest (RF), were built and optimized as the classifiers that were trained using 203 samples and applied to predict 87 testing samples. The best performance was achieved by SVM classifier in which the sensitivity of 96.55% and specificity of 98.85% were obtained in discriminating between authentic and counterfeit banknotes, and the sensitivity of 94.67% and specificity of 98.22% were obtained in predicting the types of counterfeit banknotes. These classifiers were also evaluated using the receiver operating characteristic (ROC) curves. To the best of our knowledge, this is the first study where A-scan and B-scan derived features from OCT images have been used for the detection and classification of different types of counterfeit banknotes.     

Direct and non-destructive proof of authenticity for the 2nd generation of Brazilian real banknotes via easy ambient sonic spray ionization mass spectrometry

Using a desorption/ionization technique, easy ambient sonic-spray ionization coupled to mass spectrometry (EASI-MS), documents related to the 2nd generation of Brazilian Real currency (R$) were screened in the positive ion mode for authenticity based on chemical profiles obtained directly from the banknote surface. Characteristic profiles were observed for authentic, seized suspect counterfeit and counterfeited homemade banknotes from inkjet and laserjet printers. The chemicals in the authentic banknotes' surface were detected via a few minor sets of ions, namely from the plasticizers bis(2-ethylhexyl)phthalate (DEHP) and dibutyl phthalate (DBP), most likely related to the official offset printing process, and other common quaternary ammonium cations, presenting a similar chemical profile to 1st-generation R$. The seized suspect counterfeit banknotes, however, displayed abundant diagnostic ions in the m/z 400–800 range due to the presence of oligomers. High-accuracy FT-ICR MS analysis enabled molecular formula assignment for each ion. The ions were separated by 44 m/z, which enabled their characterization as Surfynol® 4XX (S4XX, XX = 40, 65, and 85), wherein increasing XX values indicate increasing amounts of ethoxylation on a backbone of 2,4,7,9-tetramethyl-5-decyne-4,7-diol (Surfynol® 104). Sodiated triethylene glycol monobutyl ether (TBG) of m/z 229 (C₁₀H₂₂O₄Na) was also identified in the seized counterfeit banknotes via EASI(+) FT-ICR MS. Surfynol® and TBG are constituents of inks used for inkjet printing.     

Identifying Counterfeit Cigarettes Using Environmental Pollen Analysis: An Improved Procedure*

Traditional pollen preparation techniques provide clear residues for pollen identification; however, such methods are time-consuming, requiring repeated centrifugation, heating, and digestion with high-concentration hazardous chemicals. Tobacco leaves can effectively trap environmental pollen due to hairy surface and terpene-rich exudates. A new tobacco sample processing method was developed by using different extraction chemistry with surfactant. Marlboro Gold cigarettes were employed as model samples for method development. Parameters critical for pollen extraction, which include number of cigarette sticks used, extraction solution, and extraction temperature, were optimized. By using 1% dishwashing detergent to treat three cigarettes at room temperature, the improved method was able to recover sufficient pollen for microscopic analysis in three repeated centrifuge-washing steps and omit hazardous chemicals involved in traditional methods. We focused on the pollen of common ragweed (Ambrosia artemisiifolia), a plant native to North America, as an indicator to differentiate genuine and counterfeit U.S. brand cigarettes. Results from analyzing randomly purchased genuine (authenticated by forensic examination) and known counterfeit Marlboro Gold provided by law enforcement revealed that a significant amount (39%) of Ambrosia were consistently present in all genuine samples, while counterfeit contained none or only trace count. Similar results were found in other counterfeit U.S. brand cigarettes (all seized in the U.S.) involved in this study as well. Lack of Ambrosia in cigarette strongly indicates the product was not originated in the United States.     

Solving Double‐Sided Puzzles: Automated Assembly of Torn‐up Banknotes Evidence

Reconstruction of 2D object is a problem concerning many different fields such as forensics science, archiving, and banking. In the literature, it is considered as one‐sided puzzle problem. But this study handles torn banknotes as a double‐sided puzzle problem for the first time. In addition to that, a new dataset (ToB) is created for solving this problem. A selection approach based on the Borda count method is adopted in order to make the right decision as to which keypoint‐based method is to be used in the proposed reconstruction system. The selection approach was determined the Accelerated‐KAZE (AKAZE) as the most successful keypoint‐based method. This study also proposes new measures determining the success ratio of the reconstructed banknotes and calculating their loss ratio. When the torn banknotes were reconstructed with the AKAZE‐based reconstruction system, the average success rate was calculated as 95.55% by the proposed metric.     

Fingerprint detection on counterfeit US dollar banknotes: the importance of preliminary paper examination

Two seizures of counterfeit 100 US dollar bills related to the same indicative number were submitted for processing of latent fingerprints. On one group of notes, identifiable fingerprints could be detected by the routine application of amino acid reagents. In the second case, this technique gave no results, even on deliberately deposited prints. Fingerprints could be revealed, however, by cyanoacrylate fuming followed by magnetic powder. Comprehensive paper analysis showed that banknotes from both seizures differed remarkably by chemical composition as well as paper macroscopic properties. The difference in surface free energy (related to surface tension) of the banknotes in the two groups seemed to be the major factor responsible for the great variance in fingerprint detectability.     

Passport examination by a confocal-type laser profile microscope

The author proposes a nondestructive and highly precise method of measuring the thickness of a film pasted on a passport using a confocal-type laser profile microscope. The effectiveness of this method in passport examination is demonstrated. A confocal-type laser profile microscope is used to create profiles of the film surface and film–paper interface; these profiles are used to calculate the film thickness by employing an algorithm developed by the author. The film thicknesses of the passport samples—35 genuine and 80 counterfeit Japanese passports—are measured nondestructively. The intra-sample standard deviation of the film thicknesses of the genuine and counterfeit Japanese passports was of the order of 1 μm The intersample standard deviations of the film thicknesses of passports forged using the same tools and techniques are expected to be of the order of 1 μm. The thickness values of the films on the machine-readable genuine passports ranged between 31.95 μm and 36.95 μm. The likelihood ratio of this method in the authentication of machine-readable Japanese genuine passports is 11.7. Therefore, this method is effective for the authentification of genuine passports. Since the distribution of the film thickness of all forged passports was considerably larger than the accuracy of this method, this method is considered effective also for revealing the relation among the forged passports and acquiring proof of the crime.     

Consumers’ choices, infringements and market competition

The study fits the individuals?? characteristics of consumption into an analysis of the demands for both genuine goods and counterfeit goods. The consumers?? substitutability of genuine goods for counterfeits and attitudes toward a dispersed consumption of counterfeit varieties are the dimensions that affect the niche markets for counterfeits. We show that it is not necessary to increase the competition among counterfeits to reduce the demand for individual counterfeits if at the margin the variety of counterfeits enhances the value of consuming the good. The enforcements against counterfeiting deter the number of counterfeit firms, but encourage the output of individual counterfeits if the market includes a significant number of counterfeiters. The optimal private enforcement against counterfeiting is also fully discussed in the model.     

浅析纸钞的公众防伪设计

钞票是国家名片,各国为了防范伪造都在钞票上采用了大量防伪技术。钞票的防伪技术一般分为公众防伪、专业防伪和专家防伪三个层次。公众防伪特征是公众无需使用特殊设备就能鉴别钞票真假的主要手段,也是假币犯罪分子突破的重点。为了应对制假技术的提高,增强货币的防伪能力,中国人民银行和欧美等国央行也在不断对钞票进行改版提升,将最新的防伪技术应用到钞票中,同时加大宣传力度,提高普通民众对钞票防伪点的识别能力。本文调研了欧美等国央行在钞票防伪技术提升与防伪点的公众识别方面的研究,分析了新版人民币与部分国家和地区最新发行的纸质钞票的公众防伪特征,对比了不同纸钞的公众防伪特点,结合纸钞防伪设计分析,从更新钞票防伪设计、加强公众宣传等方面,为防范假币提出了建议。     

The application of infrared chemical imaging to the detection and enhancement of latent fingerprints: method optimization and further findings

Fourier transform infrared (FTIR) chemical imaging allows the collection of fingerprint images from backgrounds that have traditionally posed problems for conventional fingerprint detection methods. In this work, the suitability of this technique for the imaging of fingerprints on a wider range of difficult surfaces (including polymer banknotes, various types of paper, and aluminum drink cans) has been tested. For each new surface, a systematic methodology was employed to optimize settings such as spectral resolution, number of scans, and pixel aggregation in order to reduce collection time and file-size without compromising spatial resolution and the quality of the final fingerprint image. The imaging of cyanoacrylate-fumed fingerprints on polymer banknotes has been improved, with shorter collection times for larger image areas. One-month-old fingerprints on polymer banknotes have been successfully fumed and imaged. It was also found that FTIR chemical imaging gives high quality images of cyanoacrylate-fumed fingerprints on aluminum drink cans, regardless of the printed background. Although visible and UV light sources do not yield fingerprint images of the same quality on difficult, nonporous backgrounds, in many cases they can be used to locate a fingerprint prior to higher quality imaging by the FTIR technique. Attempts to acquire FTIR images of fingerprints on paper-based porous surfaces that had been treated with established reagents such as ninhydrin were all unsuccessful due to the swamping effect of the cellulose constituents of the paper.     

Factors influencing the contamination of UK banknotes with drugs of abuse

Bank of England banknotes sampled from different locations in the UK have been analysed for the presence of cocaine, diamorphine (DAM), Delta(9)-tetrahydrocannabinol (THC) and 3,4-methylenedioxymethamphetamine (MDMA). A database of the contamination detected is routinely used as a benchmark against which the contamination detected on seized banknotes can be compared. Evidence presented at court details how banknotes seized from a suspect may differ from banknotes in general circulation in terms of their contamination with controlled drugs. A question arising from such evidence is whether seized banknotes could have become contaminated through being in circulation in drug "hot spots". In order to address this issue, a Plackett-Burman experimental design was used to investigate the influence of source location and other factors on banknote contamination with drugs of abuse. Banknotes were drawn from banks in eight regions throughout the UK. Each location could be described by a unique combination of the factors under investigation, namely whether the location was rural or urban, in the North or South of the UK, and whether it was a port of entry. The socio-economic class and the proportion of drug offenders in the area and the denomination of the banknotes were also considered as potentially influential factors. Indices were calculated to describe the degree to which samples were contaminated with different drugs, and normal probability plots were used to identify the factors that could account for the contamination observed. Whilst some factors were more influential than others, it was shown that, at the 95% confidence level, none of the proposed factors were significant influences on the contamination. Cocaine contamination on banknotes has been shown to follow a log-normal distribution. It was, therefore, possible to calculate F- and t-statistics to compare the cocaine contamination on the entire sample set with that detected on a second sample set consisting of banknotes all drawn from a single bank branch. It was shown that both inter-bank samples and intra-bank samples had similar variance and similar contamination levels at the 95% confidence level. This suggests that there are no significant regional trends in the contamination of banknotes with drugs of abuse across the UK.     

Trace evidence dynamics of cocaine on banknotes: A comparison study of paper and polymer banknotes

It is well established that a large proportion of paper banknotes in circulation contain traces of cocaine. Being able to discriminate between the innocent transfer of illicit drug particles acquired through everyday interactions with surfaces such as banknotes, as opposed to transfer resulting from criminal activities can provide valuable intelligence that can inform an investigation. With many countries adopting polymer banknotes as legal tender, it is important to consider the transfer of cocaine from these surfaces as well as the retention of these particulates on polymer banknotes for evaluative interpretation in crime reconstruction. This comparison study assessed three contact variables (force, time, and rotation) on the transfer of cocaine particulates from paper and polymer banknotes onto a human skin proxy. The persistence of cocaine particulates was assessed through a realistic scenario which mimicked a cash transaction. Quantifiable amounts of cocaine were transferred onto the human skin proxy across all of the contacts assessed, with a greater transfer observed with contacts involving polymer banknotes and those contacts which involved rotation. Following extensive handling, cocaine persisted on both banknote types, with paper banknotes retaining larger amounts of cocaine than polymer banknotes. These findings show that cocaine can persist on both paper and polymer banknotes for extended periods of time following handling and is therefore available for transfer. This transfer then readily occurs, even when contact is brief and involves relatively small forces. A key distinction between the banknote types was that cocaine particulates are more likely to transfer from polymer banknotes due to the lower retention rate of particulates on this surface. Such insights can aid in evaluating the relevance of illicit drug particles identified on items or persons of interest in crime reconstruction approaches.     

Cue utilization in the product authentication process: a framework and research agenda for product counterfeit prevention

Scholars suggest that consumers rely on heuristics to evaluate products. They employ both extrinsic and intrinsic cues to evaluate product quality and utilize the same cues to differentiate between counterfeit and genuine products. This has far-reaching public health, economic, product authentication, and even criminal justice policy implications due to the emerging ideas of criminalizing the purchase of counterfeit goods. In order to predict the viability and the possible effects of such a policy, a thorough understanding of consumer attitudes toward counterfeits, purchase motivation, and behavior, as well as of their ability to distinguish between genuine and counterfeit goods, is imperative. Building on cue utilization theory, this article develops a framework for understanding how consumers develop and utilize heuristics for product authentication in the context of intellectual property infringements and outlines a research agenda. Additionally, it helps to inform the development of prevention and enforcement efforts, in consumer education and enforcement agent training, as well as a basis for policy decisions.     

Occurrence of contamination by controlled substances in Euro banknotes from the Spanish archipelago of the Canary Islands

The social problems of drug abuse are a matter of increasing global problem. Nowadays, international agencies need fresh methods to monitor trends of the use of illicit drugs. In this sense, small amounts of drugs are transferred to banknotes and they could be detected and quantified. An analytical procedure based upon extraction with organic solvent, liquid chromatography separation, and mass spectrometric detection allowed the identification of 21 drugs and metabolites in 120 used Euro banknotes collected in the Canary Islands (Spain). Most of the banknotes analyzed showed detectable drug residues (92.5%). Cocaine was the most frequently detected drug, present in approximately 90% of the samples. In addition, 75%, 35%, and 15% of the banknotes showed residues of amphetamine derivatives, opiates, and benzodiazepines, respectively. An average of three drug residues per banknote was detected. In summary, the presence of drug residues in banknotes could be useful as tracer for drugs prevalence.     

Counterfeiting and an Optimal Monitoring Policy

This paper studies the impact of adopting a monitoring system on counterfeiting, in which a criterion to minimize welfare losses due to counterfeiting is provided. If the degree to which the genuine product is imitated (hence the imitation rate) is not high, then counterfeit products might be allowed to exist in such a market. For the case of a high imitation rate, the use of a counterfeit monitoring regime with an optimal counterfeit-monitoring rate is the best policy. If the duration of intellectual property protection is set as infinite, then a higher monitoring rate corresponds to a narrower protection scope. Finally, the enforcement of the laws of intellectual property rights should be flexible according to a products inherent attributes as pertaining to the difficulties at imitating the original products.JEL Classification: D42, K42, L43     

Discrimination Between Infant and Adult Bloodstains Using Micro‐Raman Spectroscopy: A Preliminary Study

In the present study, we used micro‐Raman spectroscopy with high‐resolution analysis to discriminate between bloodstains from infants and bloodstains from adults. Raman peaks were detected at 674, 754, 976, 1002, 1105, 1127, 1176, 1248, 1340, 1368, 1390, 1560, and 1611 cm^?1; these peaks were derived from hemoglobin, albumin, and glucose. However, a peak was obtained at 1105 cm^?1, which was assigned to histidine; this peak was observed only for bloodstains from adults. Human adult hemoglobin (HbA) is composed of an α₂β₂ tetramer structure, whereas human fetal hemoglobin (HbF) is composed of an α₂γ₂. Therefore, the lack of a Raman peak at 1105 cm^?1 in bloodstains from infants indicates the possibility of two histidine substitutions (His116Ile and His143Ser) in the γ chain of HbF. This study discriminates between bloodstains from infants and bloodstains from adults using micro‐Raman spectroscopy, with beneficial implications in forensic science.     

How a luxury monopolist might benefit from the aspirational utility effect of counterfeiting?

Thanks to an intertemporal analytical model, we incorporate aspirational consumers in Veblen markets for luxury fashion items. We show how a luxury monopolist can increase its profits thanks to the presence of counterfeit products. The genuine producer profit is shaped by two opposite effects: (1) a positive aspirational effect resulting from a sales increase due to the aspirational consumers who seek to imitate the lifestyle of snob consumers (2) a negative snob effect, resulting from a sales decrease due to the reduction of consumption by some snob consumers. We identify the conditions under which the overall effect generated by counterfeiting can increase the genuine firm profit. These conditions imply the existence of large aspirational effects and high additional utility gain associated with buying an original product instead of obtaining a counterfeit product.     

Comparison of the elemental composition of office document paper: evidence in a homicide case

Fraudulent substitution of a page within a multiple page document such as a will or business contract, the counterfeit manufacture of paper banknotes, and linking ransom or extortion notes have all been the focus of criminal investigations at one time or another. In a recent homicide investigation, document examiners were requested to compare a threatening letter received by a business partner of the deceased with paper samples seized under warrant from a suspect's house. Through a quantitative elemental analysis of the concentrations of nine elements (Na, Mg, Al, Mn, Sr, Y, Ba, La, and Ce) within the questioned and specimen documents, determined by inductively coupled plasma-mass spectrometry (ICP-MS), it was concluded that (i) the paper of the threatening letter originated from a different source to that of the paper seized from the suspect's house and (ii) all six pages of paper seized from the suspect's house originated from the same source. This discrimination of paper is presented as both a statistical t-test analysis (99.9% confidence limit) as well as construction of an elemental fingerprint for individual replicates within the questioned and specimen sample populations. This is the first reported use of the comparison of the elemental composition of document paper, determined by ICP-MS, to assist in a criminal investigation.     

Quantitative Analysis of Sildenafil and Tadalafil in Various Fake Drugs Recently Distributed in Korea

Abstract: Illicit distribution of various illicit or counterfeit drugs containing sildenafil and tadalafil has increased and caused noticeable problems in Korea. This study has been performed to determine the content range of sildenafil and tadalafil in various fake drugs. Among the illicit or counterfeit drugs seized by Korean authorities, 105 exhibits were used for the quantification. HPLC–UV analysis of methanol extractions was used for separation and quantitation of the two target compounds. The most abundant type of fake drug was counterfeit Viagra^® tablets. Sildenafil was found in 73 exhibits, and tadalafil was found in seven exhibits. Twenty‐five exhibits out of the 105 contained both sildenafil and tadalafil. The contents of sildenafil ranged from 4.3 to 453.2 mg; for tadalafil, the range was 2.2–40.4 mg. The proportion of cases of having more than 100 mg of sildenafil was 50% and 78% had more than 20 mg of tadalafil.     

A rapid and sensitive method for the identification of delta-9-tetrahydrocannabinol in oral fluid by liquid chromatography-tandem mass spectrometry

This paper proposes a new approach for automatic classification of counterfeit Viagra(?) and Cialis(?) tablets using image processing and statistical analysis. A high resolution VSC 5000 is used for image acquisition in a controlled environment, and the combination of a thresholding technique with morphological operators is used to segment the tablet from the background. A statistical model based on the RGB color components of original samples is built, and the detection of counterfeit tablets was performed by checking the adherence of a test sample to the obtained distribution using the Bhattacharyya distance. Our experimental results indicated that counterfeit tablets can be effective detected using the proposed approach.     

Detection of counterfeit antiviral drug Heptodin™ and classification of counterfeits using isotope amount ratio measurements by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) and isotope ratio mass spectrometry (IRMS)

Isotope ratio mass spectrometry (IRMS) and multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) are highly important techniques that can provide forensic evidence that otherwise would not be available. MC-ICP-MS has proved to be a very powerful tool for measuring high precision and accuracy isotope amount ratios. In this work, the potential of combining isotope amount ratio measurements performed by MC-ICP-MS and IRMS for the detection of counterfeit pharmaceutical tablets has been investigated.An extensive study for the antiviral drug Heptodin™ has been performed for several isotopic ratios combining MC-ICP-MS and an elemental analyser EA-IRMS for stable isotope amount ratio measurements. The study has been carried out for 139 batches of the antiviral drug and analyses have been performed for C, S, N and Mg isotope ratios. Authenticity ranges have been obtained for each isotopic system and combined to generate a unique multi-isotopic pattern only present in the genuine tablets. Counterfeit tablets have then been identified as those tablets with an isotopic fingerprint outside the genuine isotopic range.The combination of those two techniques has therefore great potential for pharmaceutical counterfeit detection. A much greater power of discrimination is obtained when at least three isotopic systems are combined. The data from these studies could be presented as evidence in court and therefore methods need to be validated to support their credibility. It is also crucial to be able to produce uncertainty values associated to the isotope amount ratio measurements so that significant differences can be identified and the genuineness of a sample can be assessed.