Yevhen ZOLOTAVKIN

Professional researcher with a solid foundation in conducting high-impact studies and producing influential research findings in security and privacy of complex systems. Known for strong collaboration skills and adaptability in dynamic environments. Expertise in diverse methodologies, data interpretation, and scientific writing, ensuring reliable and actionable results. Experienced with comprehensive research design and implementation, delivering impactful studies that advance scientific understanding utilizing advanced mathematical modeling and data analysis techniques to uncover critical insights with a track record of collaborative teamwork and effective project management.

• ACM member since 2006
• IEEE member since 2007
• Member of Data Analysis Research Group (DARG) and Centre for Applied Statistics and Data Analytics (CAST), University of Tampere, between 2012 and 2015
• Member of the National Association of Early Career Scientists (Ukraine) between 2008 and 2012

• Detailed synopsis of PhD thesis “New Methods for Digital Image Watermarking”
• Methods of Digital Image Watermarking (DIW) are detailed and discussed in this thesis. Attention is paid to the purposes of DIW, its efficiency and technical aspects that can improve it. Digital Rights can be protected by combining original multimedia content with a small amount of artificially created data called a watermark. In that way, the watermarked media remains usable by a third party who can not modify ownership information. However, different kinds of noise may target the watermarked media during its transmission, as well as different processing techniques or attacks might be applied by a third party. The efficiency of a watermarking method depends on two factors: its ability to resist negative influence and preserve watermark data; degradation it causes to the original media. The common goal in DIW is to increase resistance (robustness) while reducing degradation (improving transparency) of the original.
• The following technical aspects influencing watermarking efficiency were addressed in the thesis: type of transform used for watermarking; techniques used for watermark encoding and decoding. The transform utilized by all the methods represented in the thesis consists of splitting the original image into square non-overlapping blocks with subsequent Singular Value Decomposition (SVD) of each block. Proposed in the thesis, encoding/decoding techniques can be classified according to the components of SVD they modify that are either columns of orthonormal matrices, or Singular Values (SV). During the procedure of watermark encoding, special attention is paid to the condition of orthonormality for the modified matrix as well as the requirement to reduce degradation induced by watermarking. In particular, for image blocks of 4x4 pixels, was chosen model based on Van Elfrinkhof’s rotation matrix. SV are modulated using modifications of Quantization Index Modulation (QIM) with Distortion Compensation (DC), which provides sufficiently high robustness against certain types of noise.
• The achievements were confirmed experimentally and compared with relevant watermarking methods described in the literature. For that purpose, the measure of the transparency of watermarked images was based on Mean Square Error (MSE). The robustness of watermarked images was based on Bit Error Rate (BER) and other information related indices.
• Synopsis of Candidate of Sciences dissertation “Methods and tools with improved resilience to passive steganographic attacks”
• The thesis studies steganographic resilience under passive attacks and develops software means for the protection of information about navigation trajectory during high-precision aerial photography filming.
• Two different methods were considered for invisible information embedding into digital images: a) vector modulation based on Gramm-Schmidt reconstruction guided by the approximated (Group Method of Data Handling Algorithms) goal function; b) alteration of fractal compression code of an image.
• In order to design both methods, we proposed a new framework for steganographic embedding and recovery in the presence of an adversarial agent whose task is to detect the presence of stego-payload inside an image. Special attention was paid to the SVM detector properties and description of corresponding detection constraints using GMDH approximation.
• The developed vector-modulation and fractal-based methods provide up to 32% and 11% lower detection rates, respectively, in comparison to the existing methods. Based on the latter fractal-embedding method, we developed the software product «StegoFractal» that was implemented to protect commercial data during costly aerial footage conducted by the company “GeoSystem” (http://www.vingeo.com/geosyst.html ).

• Y. Zolotavkin, J. Jeong, V. Kuchta, M. Slavenko, R. Doss “Improving Unlinkability of Attribute Based Authentication through Game Theory”, Under review: ACM Transactions on Privacy and Security (TOPS), (core A ranking)
• J. Jeong, Y. Zolotavkin, R. Doss “Examining the Current Status and Emerging Trends in Continuous Authentication Technologies through Citation Network Analysis”, Under review: ACM Computing Surveys (CSUR), (core A
• Ranking)
• N. Lalchandani, J. Jeong, Y. Zolotavkin, F. Jiang, R. Doss “Evaluating the Current State of Application Programming Interfaces for Verifiable Credentials”, Accepted to: The 18th annual International Conference on Privacy, Security, and Trust, (PST’21 – core C ranking), Dec 2021, Auckland, New Zealand. https://pstnet.ca/
• M. Slavenko, Y. Zolotavkin, J. Jeong, V. Kuchta, and R. Doss “Enhancing Privacy Through DMMA: Decision-Making Model for Authentication”, Accepted to: IEEE International Conference on Trust, Security and Privacy in Computing and Communications (TrustCom), (TrustCom – core B ranking), Nov 2021, Shenyang, China. https://trustcom2021.sau.edu.cn/
• L. Yu, J. Yu, Y. Zolotavkin “Game Theoretic Analysis of Reputation Approach on Block Withholding Attack”, Accepted to: International Conference on Network and System Security, (NSS – core B ranking), Nov. 2020, Melbourne. http://nslab.org/nss2020/
• Y. Zolotavkin, V. Kuchta “Incentives for Harvesting Attack in Proof of Work mining pools”, In proceedings: The European Symposium on Research in Computer Security, (ESORICS – core A ranking), September 2019, Luxemburg. https://esorics2019.uni.lu/
• Y. Zolotavkin, J. Garcia, J. Liu “Time-dependent Decision-making and Decentralization in Proof-of-Work Cryptocurrencies”, In proceedings: 32nd IEEE Computer Security Foundations Symposium (CSF – core A ranking), June 2019, Hoboken, NJ, USA. https://web.stevens.edu/csf2019/accepted.html
• Y. Zolotavkin, J. Garcia “Incentives for Stable Mining in Pay Per Last N Shares Pools”, In proceedings: IFIP Networking 2019 (core A ranking), May 2019, Warsaw, Poland. https://networking.ifip.org/2019/index.php/program
• Y. Zolotavkin, J. Garcia, and C. Rudolph “Incentive compatibility of pay per last N shares in bitcoin mining pools”, in Decision and Game Theory for Security, S. Rass, B. An, C. Kiekintveld, F. Fang, and S. Schauer, Eds., Cham: Springer International Publishing, 2017, pp. 21–39. https://link.springer.com/chapter/10.1007/978-3-319-68711-7_2
• Chaudhary, S., Berki, E., Helenius, M., Nykänen, P., Zolotavkin, Y., Kela, J.: Towards a Framework for Privacy Protection in the Use of Interactive 360 Video Surveillance. In: The 22nd International Conference on Virtual Systems & Multimedia (VSMM – core B ranking) 2016 (October 2016), Malaysia. https://ieeexplore.ieee.org/document/7863179
• Zolotavkin, Y., Juhola, M.: A New Scalar Quantization Method for Digital Image Watermarking. Journal of Electrical and Computer Engineering, vol. 2016, Article ID 9029745, pp. 1-16 (Feb 2016). http://www.hindawi.com/journals/jece/2016/9029745/
• Zolotavkin, Y., Juhola, M.: A New Two-Dimensional Quantization Method for Digital Image Watermarking. In : Proceedings of IEEE International Conference on Advanced Communications Technology (ICACT’15) (July 2015), Korea, pp. 155-160. http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7224776&isnumber=7224736
• Zolotavkin, Y., Juhola, M.: Quantization Based Watermarking Approach with Gain Attack Recovery. In : Proceedings of the IEEE International Conference on Digital Image Computing: Techniques and Applications (DICTA’14 – core Australasian ranking), Wollongong, pp.1-8 (Nov 2014). http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7008125&isnumber=7008073
• Zolotavkin, Y., Juhola, M.: A New QIM-Based Watermarking Method Robust to Gain Attack. International Journal of Digital Multimedia Broadcasting, Vol 2014 (Art 910808), pp. 1-14 (Sep 2014). http://www.hindawi.com/journals/dmb/2014/910808/
• Zolotavkin, Y., Juhola, M.: A new blind adaptive watermarking method based on singular value decomposition. In : International Conference on Sensor Network Security Technology and Privacy Communication Systems (SNS & PCS 2013), Harbin, pp.184-192 (May 2013). http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6553862&isnumber=6553822
• Zolotavkin, Y., Juhola, M.: An SYD-based Transparent Watermarking Method. In : Proceedings of the International Conference on E-Technologies and Business on the Web (EBW2013), Bangkok, pp.85-90 (May 2013). http://sdwinc.net/digital-library/an-svdbased-transparent-watermarking-method.html
• Zolotavkin, Y., Juhola, M.: SVD-based Digital Image Watermarking on Approximated Orthogonal Matrix. In : Proceedings of the 10th International Conference on Security and Cryptography (SECRYPT 2013 – core B ranking), Reykjavik, pp.321-330 (July 2013). http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7223181&isnumber=7223120
• Zolotavkin, Y., Lukichov, V., Vasyura, A.: A novel approach to the security of data hidden in multimedia objects. In : Proceedings of 42nd Annual IEEE International Carnahan Conference on Security Technology, 2008 (ICCST 2008), Prague, pp.23-28 (Oct 2008). http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4751271&isnumber=4751258
• Lukichov, V., Vasyura, A., Zolotavkin, Y.: Improvement of pattern hiding method of data application in JPEG-files. In : Proceedings of 42nd Annual IEEE International Carnahan Conference on Security Technology, 2008 (ICCST 2008), Prague, pp.69-75 (2008). http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=4751279&isnumber=4751258