A secure restful deployment pattern for course recommendation microservices using proof-of-work blockchain authentication
DOI: https://doi.org/10.3846/ntcs.2026.26620Abstract
Deploying machine learning models across distributed environments requires robust architectural patterns that ensure both cross-platform interoperability and secure access control. While Representational State Transfer (REST) APIs are widely adopted for service exposure, existing implementations in cross-machine scenarios remain vulnerable to token spoofing and post-hoc administrative tampering of centralized authorization logs. Therefore, this study presents a secure, deployable architectural pattern that integrates localized machine learning workflows with a decentralized authentication boundary. An online course recommendation system using text preprocessing, Term Frequency–Inverse Document Frequency (TF–IDF) vectorization, and cosine similarity is implemented and utilized explicitly as a functional demonstration case to validate the framework. The core machine learning engine is exposed via a Flask-implemented RESTful service layer, while secure access control is enforced by embedding a Proof-of-Work (PoW) blockchain token authentication mechanism at the API boundary. The empirical results demonstrate that access to protected endpoints is granted only upon successful validation of user tokens against immutable on-chain ledger records, structurally rejecting unauthorized requests. Performance benchmarking indicates that while the decentralized ledger operations introduce an operational latency trade-off (a 1113 ms mining overhead and 2.45-second end-to-end authorized query response), the proposed pattern provides an effective, tamper-evident firewall for delivering secure microservices in distributed client–server environments.
Keywords:
REST API, deployment architecture, machine learning microservices, blockchain, proof-of-work authentication, content-based filteringHow to Cite
Share
License
Copyright (c) 2026 The Author(s). Published by Vilnius Gediminas Technical University.

This work is licensed under a Creative Commons Attribution 4.0 International License.
References
Anand, P. B., & Nath, R. (2020). Content‐based recommender systems. In S. N. Mohanty, J. M. Chatterjee, S. Jain, A. A. Elngar, & P. Gupta (Eds.), Recommender system with machine learning and artificial intelligence (pp. 165–195). Wiley. https://doi.org/10.1002/9781119711582.ch9
Apriani, A., Zakiyudin, H., & Marzuki, K. (2021). Penerapan Algoritma Cosine Similarity dan Pembobotan TF-IDF System Penerimaan Mahasiswa Baru pada Kampus Swasta. Jurnal Bumigora Information Technology (BITe), 3(1), 19–27. https://doi.org/10.30812/bite.v3i1.1110
Bajpai, P., Suryawanshi, N., Orse, A., Srivastava, H., Patil, M., & Lavale, B. (2022). E-learning recommendation system. International Journal for Research in Applied Science & Engineering Technology (IJRASET), 10, 2321–9653. https://doi.org/10.22214/ijraset.2022.42706
Bigelow, S. J. (2020). 5 stages of an API lifecycle explained. https://www.techtarget.com/searchapparchitecture/feature/5-stages-of-an-API-lifecycle-explained
da Silva, F. L., Slodkowski, B. K., da Silva, K. K. A., & Cazella, S. C. (2023). A systematic literature review on educational recommender systems for teaching and learning: Research trends, limitations and opportunities. Education and Information Technologies, 28(3), 3289–3328. https://doi.org/10.1007/s10639-022-11341-9
Dharma, B., & Muslikh, A. R. (2025). Implementasi rate limiting dan Bot Telegram untuk mitigasi serangan HTTP GET Flood. Journal of Information System and Application Development. https://doi.org/10.26905/jisad.v3i1.15398
Drescher, D. (2017). Blockchain basics: A non-technical introduction in 25 steps. In Blockchain basics: A non-technical introduction in 25 steps. Apress Media LLC. https://doi.org/10.1007/978-1-4842-2604-9
Fayyaz, Z., Ebrahimian, M., Nawara, D., Ibrahim, A., & Kashef, R. (2020). Recommendation systems: Algorithms, challenges, metrics, and business opportunities. Applied Sciences, 10(21), Article 7748. https://doi.org/10.3390/app10217748
García, I., & Bellogín, A. (2018, June). Towards an open, collaborative REST API for recommender systems. In RecSys 2018 – 12th ACM Conference on Recommender Systems (pp. 504–505). Association for Computing Machinery. https://doi.org/10.1145/3240323.3241615
Habibi, M., & Cahyo, P. W. (2020). Journal classification based on abstract using cosine similarity and support vector machine. JISKA (Jurnal Informatika Sunan Kalijaga), 4(3), 185–192. https://doi.org/10.14421/jiska.2020.43-06
Jain, H., & Kakkar, M. (2019). Job recomemendation system based on ML & DM techniques using RESful API and Android IDE. In 2019 9th International Conference on Cloud Computing, Data Science & Engineering (Confluence) (pp. 416–421). IEEE. https://doi.org/10.1109/CONFLUENCE.2019.8776964
Javed, U., Shaukat, K., Hameed, I. A., Iqbal, F., Alam, T. M., & Luo, S. (2021). A review of content-based and context-based recommendation systems. International Journal of Emerging Technologies in Learning, 16(3), 274–306. https://doi.org/10.3991/ijet.v16i03.18851
Kalyanasundaram, T., Panchalingam, K., Jegatheesan, T., Wijayasiri, A., & Perera, S. (2025). Load balancer filter-based approach to enable distributed API rate limiting. In 2025 37th Conference of Open Innovations Association (FRUCT) (pp. 75–85). IEEE. https://doi.org/10.23919/fruct65909.2025.11008311
Kapoor, K. (2021). Coursera courses dataset 2021 [Data set]. https://www.kaggle.com/datasets/khusheekapoor/coursera-courses-dataset-2021
Kumar, N., Gupta, M., Sharma, D., & Ofori, I. (2022). Technical job recommendation system using APIs and Web crawling. Computational Intelligence and Neuroscience, 2022, Article 7797548. https://doi.org/10.1155/2022/7797548
Li, M. (2024). Recommendation system building based on CNN and TF-IDF approaches. Highlights in Science, Engineering and Technology, 92, 178–187. https://doi.org/10.54097/633gjj39
Lyu, N., Wang, Y., Cheng, Z., Zhang, Q., & Chen, F. (2025). Multi-objective adaptive rate limiting in microservices using deep reinforcement learning. In Proceedings of the 4th International Conference on Artificial Intelligence and Intelligent Information Processing (pp. 862–869). Association for Computing Machinery. https://doi.org/10.1145/3778534.3778668
Manoharan, M. (2024). API rate limiting mechanisms in SaaS applications: A systematic analysis of DDoS protection strategies. International Journal of Scientific Research in Computer Science, Engineering and Information Technology, 10(6), 1787–1798. https://doi.org/10.32628/cseit241061223
Mawanta, I., Gunawan, T. S., & Wanayumini, W. (2021). Uji Kemiripan Kalimat Judul Tugas Akhir dengan Metode Cosine Similarity dan Pembobotan TF-IDF. Jurnal Media Informatika Budidarma, 5(2), 726–738. https://doi.org/10.30865/mib.v5i2.2935
Mohanty, S. N., Chatterjee, J. M., Jain, S., Elngar, A. A., & Gupta, P. (2020). Content-based recommender systems. In F. Ricci, L. Rokach, B. Shapira, & P. Kantor (Eds.), Recommender system with machine learning and artificial intelligence (pp. 167–195). Springer. https://doi.org/10.1002/9781119711582
Ni, J., Cai, Y., Tang, G., & Xie, Y. (2021). Collaborative filtering recommendation algorithm based on TF-IDF and user characteristics. Applied Sciences, 11(20), Article 9554. https://doi.org/10.3390/app11209554
OpenAPI Initiative. (2020). OpenAPI specification (Version 3.0.3) [Specification]. https://spec.openapis.org/oas/v3.0.3.html
Pal, N., & Dahiya, O. (2023). Analysis of educational recommender system techniques for enhancing student’s learning outcomes. In 2023 3rd International Conference on Innovative Practices in Technology and Management (ICIPTM) (pp. 1–5). IEEE. https://doi.org/10.1109/ICIPTM57143.2023.10118132
Parvatikar, S., & Parasar, D. (2021). Recommendation system using machine learning. International Journal of Artificial Intelligence and Machine Learning, 1(1), 24–30. https://doi.org/10.51483/IJAIML.1.1.2021.24-30
Podduturi, S. M. (2024). Security and performance optimization in microservices for real-time data systems. International Journal for Multidisciplinary Research, 6(6). https://doi.org/10.36948/ijfmr.2024.v06i06.33239
Portugal, I., Alencar, P., & Cowan, D. (2018). The use of machine learning algorithms in recommender systems: A systematic review. Expert Systems with Applications, 97, 205–227. https://doi.org/10.1016/j.eswa.2017.12.020
Rani, P., & Bhambay, R. (2023). A comparative survey of consensus algorithms based on proof of work. In P. Dutta, S. Chakrabarti, A. Bhattacharya, S. Dutta, & V. Piuri (Eds.), Emerging technologies in data mining and information security (pp. 261–268). Springer Nature Singapore. https://doi.org/10.1007/978-981-19-4193-1_25
Raschka, S., Patterson, J., & Nolet, C. (2020). Machine learning in python: Main developments and technology trends in data science, machine learning, and artificial intelligence. Information, 11(4), Article 193. https://doi.org/10.3390/info11040193
Sultana, R., & Khan, R. (2025). AI-based rate limiting for cloud infrastructure: Implementation guide. Journal of Computer Science and Technology Studies, 7(3), 370–380. https://doi.org/10.32996/jcsts.2025.7.3.43
Thakur, A. (2021). Automated online course recommendation system using collaborative filtering. International Journal for Research in Applied Science and Engineering Technology, 9(2), 222–229. https://doi.org/10.22214/ijraset.2021.33043
van Flymen, D. (2020). Learn blockchain by building one: A concise path to understanding cryptocurrencies. Springer International Publishing. https://doi.org/10.1007/978-1-4842-5171-3
Wahyuni, R. T., Prastiyanto, D., & Supraptono, E. (2017). Penerapan Algoritma Cosine Similarity dan Pembobotan TF-IDF pada Sistem Klasifikasi Dokumen Skripsi. Jurnal Teknik Elektro Universitas Negeri Semarang, 9(1), 18–23. https://journal.unnes.ac.id/nju/index.php/jte/article/download/10955/6659
Yusuf, M., & Cherid, A. (2020). Implementasi Algoritma Cosine Similarity Dan Metode TF-IDF Berbasis PHP Untuk Menghasilkan Rekomendasi Seminar. Jurnal Ilmiah Fakultas Ilmu Komputer, 9(1), 8–16. https://publikasi.mercubuana.ac.id/index.php/fasilkom/article/view/8830
View article in other formats
Published
Issue
Section
Copyright
Copyright (c) 2026 The Author(s). Published by Vilnius Gediminas Technical University.
License

This work is licensed under a Creative Commons Attribution 4.0 International License.