Stability and Specificity of Counterfeit Protection System Code |
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| Authors: | Jiang‐Chun Li M.S. Fang Fang B.S. Xing‐Zhou Han Ph.D. Biao Li M.S. Wei Han Ph.D. Qian Zhou M.S. |
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| Affiliation: | 1. Hubei Key Laboratory of Forensic Science, Department of Forensic Science and Intelligence, Hubei University of Police, Wuhan, ChinaCorresponding author: Qian Zhou, M.S. E‐mail:;2. The Judicial Authentication Center of Zhejiang Han Bo, Hangzhou, China;3. Institute of Forensic Science, Ministry of Public Security, Beijing, China;4. Department of Questioned Documents, The China Criminal Police University, Shenyang, China;5. Yantai Public Security of Shan Dong province, Yantai, China;6. Hubei Key Laboratory of Forensic Science, Department of Forensic Science and Intelligence, Hubei University of Police, Wuhan, China |
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| Abstract: | In this study, the stability and specificity of a counterfeit protection system (CPS) code were determined. This research involved an analysis of a counterfeit protection system code unit over time using the pattern location measurement method. We collected 379 sample sheets from 196 printers or photocopiers, covering 14 original brands, including 129 models. There was an interval of at least two months between the collections of samples from each machine. Four types of characteristics were established: CPS pattern unit, distance of the CPS unit, position of dots, size and shape of the dot. Except for the partial changes in the Xerox brand, no other brand exhibited changes over time. This implies that the CPS characteristics are stable. Meanwhile, no correlation was noted between the combinations of the characteristic systems in the collected samples, which implied strong specificity. |
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| Keywords: | forensic science questioned document color laser print stability and specificity counterfeit protection system code counterfeit protection system code pattern |
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