{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T16:38:31Z","timestamp":1775839111337,"version":"3.50.1"},"reference-count":37,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2021,4,27]],"date-time":"2021-04-27T00:00:00Z","timestamp":1619481600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100010418","name":"Institute for Information and Communications Technology Promotion","doi-asserted-by":"publisher","award":["2020-2020-0-01789"],"award-info":[{"award-number":["2020-2020-0-01789"]}],"id":[{"id":"10.13039\/501100010418","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100003725","name":"National Research Foundation of Korea","doi-asserted-by":"publisher","award":["2018R1A5A7023490"],"award-info":[{"award-number":["2018R1A5A7023490"]}],"id":[{"id":"10.13039\/501100003725","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Digital evidence, such as evidence from CCTV and event data recorders, is highly valuable in criminal investigations, and is used as definitive evidence in trials. However, there are risks when digital evidence obtained during the investigation of a case is managed through a physical hard disk drive until it is submitted to the court. Previous studies have focused on the integrated management of digital evidence in a centralized system, but if a centralized system server is attacked, major operations and investigation information may be leaked. Therefore, there is a need to reliably manage digital evidence and investigation information using blockchain technology in a distributed system environment. However, when large amounts of data\u2014such as evidence videos\u2014are stored in a blockchain, the data that must be processed only within one block before being created increase, causing performance degradation. Therefore, we propose a two-level blockchain system that separates digital evidence into hot and cold blockchains. In the criminal investigation process, information that frequently changes is stored in the hot blockchain, and unchanging data such as videos are stored in the cold blockchain. To evaluate the system, we measured the storage and inquiry processing performance of digital crime evidence videos according to the different capacities in the two-level blockchain system.<\/jats:p>","DOI":"10.3390\/s21093051","type":"journal-article","created":{"date-parts":[[2021,4,27]],"date-time":"2021-04-27T21:18:20Z","timestamp":1619558300000},"page":"3051","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":39,"title":["Two-Level Blockchain System for Digital Crime Evidence Management"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8889-275X","authenticated-orcid":false,"given":"Donghyo","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Computer Science and Engineering, Dongguk University, Seoul 04620, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7545-7035","authenticated-orcid":false,"given":"Sun-Young","family":"Ihm","sequence":"additional","affiliation":[{"name":"Department of Computer Engineering, Pai Chai University, Daejeon 35345, Korea"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2580-4393","authenticated-orcid":false,"given":"Yunsik","family":"Son","sequence":"additional","affiliation":[{"name":"Department of Computer Science and Engineering, Dongguk University, Seoul 04620, Korea"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,27]]},"reference":[{"key":"ref_1","unstructured":"Jonston, A. (2021, April 27). Murder Charges Filed in 1985 Cold Case, Available online: https:\/\/oag.ok.gov\/articles\/murder-charges-filed-1985-cold-case."},{"key":"ref_2","unstructured":"Choi, S.W. (2021, April 27). Every Crime Leaves a Mark. Available online: https:\/\/sedaily.com\/NewsView\/1OMAEK89A4."},{"key":"ref_3","unstructured":"Police Agency in Korea Police (2019). White Paper: A Society Safe from Crime, Korean National Police Agency."},{"key":"ref_4","first-page":"1","article-title":"Management from the perspective of the Life Cycle of Digital Evidence","volume":"10","author":"Jung","year":"2016","journal-title":"J. Digit. Forensics"},{"key":"ref_5","first-page":"760","article-title":"Design and Implementation of a Digital Evidence Management Model Based on Hyperledger Fabric","volume":"16","author":"Jeong","year":"2020","journal-title":"J. Inf. Process. Syst."},{"key":"ref_6","unstructured":"Tak, H.S., and Lee, W.S. (2016). A Study on a Model Frame for the Integration of Digital Forensic Processes, Korean Institute of Criminology."},{"key":"ref_7","unstructured":"Arslan, S.S., and Goker, T. (2020, January 2\u20135). Compress-Store on Blockchain: A Decentralized Data Processing and Immutable Storage for Multimedia Streaming. Proceedings of the IEEE BCCA, Antalya, Turkey."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Sahoo, S., Fajge, A.M., Halder, R., and Cortesi, A. (2019). A Hierarchical and Abstraction-Based Blockchain Model. Appl. Sci., 9.","DOI":"10.3390\/app9112343"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Oktian, Y.E., Lee, S.-G., and Lee, H.J. (2020). Hierarchical Multi-Blockchain Architecture for Scalable Internet of Things Environment. Electronics, 9.","DOI":"10.3390\/electronics9061050"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Albizri, A., and Appelbaum, D. (2021). Trust but Verify: The Oracle Paradox of Blockchain Smart Contracts. J. Inf. Syst.","DOI":"10.26226\/morressier.5f0c7d3058e581e69b05d17c"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"S64","DOI":"10.1016\/j.diin.2010.05.009","article-title":"Digital forensics research: The next 10 years","volume":"7","author":"Garfinkel","year":"2010","journal-title":"Digit. Investig."},{"key":"ref_12","unstructured":"Frankle, J., Park, S., Shaar, D., Goldwasser, S., and Weitzner, D. (2018, January 15\u201317). Practical accountability of secret processes. Proceedings of the 27th USENIX Security Symposium, Baltimore, MD, USA."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Norvill, R., Pontiveros, B.B.F., State, R., and Cullen, A. (August, January 30). IPFS for Reduction of Chain Size in Ethereum. Proceedings of the 2018 IEEE International Conference on Internet of Things (iThings) and IEEE Green Computing and Communications (GreenCom) and IEEE Cyber, Physical and Social Computing (CPSCom) and IEEE Smart Data (SmartData), Halifax, NS, Canada.","DOI":"10.1109\/Cybermatics_2018.2018.00204"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Hoffman, A., Becerril-Blas, E., Moreno, K., and Kim, Y. (2020, January 6\u20138). Decentralized Security Bounty Management on Blockchain and IPFS. Proceedings of the 2020 10th Annual Computing and Communication Workshop and Conference (CCWC), Las Vegas, NV, USA.","DOI":"10.1109\/CCWC47524.2020.9031109"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"59389","DOI":"10.1109\/ACCESS.2020.2982964","article-title":"Blockchain-Based Secure Storage and Access Scheme For Electronic Medical Records in IPFS","volume":"8","author":"Sun","year":"2020","journal-title":"IEEE Access"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Kumar, R., Marchang, N., and Tripathi, R. (2020, January 7\u201311). Distributed Off-Chain Storage of Patient Diagnostic Reports in Healthcare System Using IPFS and Blockchain. Proceedings of the 2020 International Conference on COMmunication Systems & NETworkS (COMSNETS), Bangalore, India.","DOI":"10.1109\/COMSNETS48256.2020.9027313"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Naz, M., Al-Zahrani, F.A., Khalid, R., Javaid, N., Qamar, A.M., Afzal, M.K., and Shafiq, M. (2019). A Secure Data Sharing Platform Using Blockchain and Interplanetary File System. Sustainability, 11.","DOI":"10.3390\/su11247054"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Donawa, A., Orukari, I., and Baker, C.E. (2019, January 10\u201312). Scaling Blockchains to Support Electronic Health Records for Hospital Systems. Proceedings of the 2019 IEEE 10th Annual Ubiquitous Computing, Electronics & Mobile Communication Conference (UEMCON), New York, NY, USA.","DOI":"10.1109\/UEMCON47517.2019.8993101"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Jeong, J., Kim, D., Ihm, S.-Y., Lee, Y., and Son, Y. (2021). Multilateral Personal Portfolio Authentication System Based on Hyperledger Fabric. ACM Trans. Internet Technol., 21.","DOI":"10.1145\/3423554"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1109\/MCOM.2018.1800137","article-title":"Block4Forensic: An Integrated Lightweight Blockchain Framework for Forensics Applications of Connected Vehicles","volume":"56","author":"Cebe","year":"2018","journal-title":"IEEE Commun. Mag."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1016\/j.future.2020.09.038","article-title":"LEChain: A blockchain-based lawful evidence management scheme for digital forensics","volume":"115","author":"Li","year":"2021","journal-title":"Future Gener. Comput. Syst."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Gursoy, G., Barnnon, C., Wanger, S., and Gerstein, M. (2020). Storing and analyzing a genome on a blockchain. bioRxiv.","DOI":"10.1101\/2020.03.03.975334"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Nyaletey, E., Parizi, R.M., Zhang, Q., and Choo, K.-K.R. (2019, January 14\u201317). BlockIPFS\u2014Blockchain-Enabled Interplanetary File System for Forensic and Trusted Data Traceability. Proceedings of the 2019 IEEE International Conference on Blockchain (Blockchain), Atlanta, GA, USA.","DOI":"10.1109\/Blockchain.2019.00012"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"34045","DOI":"10.1109\/ACCESS.2019.2904042","article-title":"Privacy-Oriented Blockchain-Based Distributed Key Management Architecture for Hierarchical Access Control in the IoT Scenario","volume":"7","author":"Ma","year":"2019","journal-title":"IEEE Access"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Li, C., and Zhang, L.-J. (2017, January 25\u201330). A Blockchain Based New Secure Multi-Layer Network Model for Internet of Things. Proceedings of the 2017 IEEE International Congress on Internet of Things (ICIOT), Honolulu, HI, USA.","DOI":"10.1109\/IEEE.ICIOT.2017.34"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Mielberg, E.L. (2019). Blockchain Remedy or Poison. OSF Preprints.","DOI":"10.31219\/osf.io\/t7qwj"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Zamani, M., Movahedi, M., and Raykova, M. (2018, January 15\u201319). Rapidchain: Scaling blockchain via full sharding. Proceedings of the ACM SIGSAC Conference on Computer and Communications Security, Toronto, ON, Canada.","DOI":"10.1145\/3243734.3243853"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Park, J., Kim, H., Kim, G., and Ryou, J. (2020). Smart Contract Data Feed Framework for Privacy-Preserving Oracle System on Blockchain. Computers, 10.","DOI":"10.3390\/computers10010007"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1504\/IJWGS.2018.095647","article-title":"Blockchain challenges and opportunities: A survey","volume":"14","author":"Zheng","year":"2018","journal-title":"Int. J. Web Grid Serv."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1211","DOI":"10.1093\/jamia\/ocx068","article-title":"Blockchain distributed ledger technologies for biomedical and health care applications","volume":"24","author":"Kuo","year":"2017","journal-title":"J. Am. Med. Inform. Assoc."},{"key":"ref_31","unstructured":"Rubin, J., Naik, M., and Subramanian, N. (2021, April 27). Merkelized Abstract Syntax Trees. Available online: http:\/\/www.mit.edu\/~jlrubin\/public\/pdfs\/858report.pdf."},{"key":"ref_32","first-page":"1","article-title":"Consortium Blockchain for Secure Energy Trading in Industrial Internet of Things","volume":"14","author":"Li","year":"2017","journal-title":"IEEE Trans. Ind. Inform."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"102136","DOI":"10.1016\/j.ijinfomgt.2020.102136","article-title":"Permissionless and permissioned blockchain diffusion","volume":"54","author":"Helliar","year":"2020","journal-title":"Int. J. Inf. Manag."},{"key":"ref_34","unstructured":"Satoshi, N. (2021, April 27). Bitcoin: A Peer-to-Peer Electronic Cash System. Available online: https:\/\/git.dhimmel.com\/bitcoin-whitepaper."},{"key":"ref_35","unstructured":"(2021, April 27). Christoper Ferris, Hyperledger Fabric Introduction. Available online: https:\/\/hyperledger-fabric.readthedocs.io\/en\/release-2.2\/."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Chen, Y., Li, H., Zheng, B., and Bian, J. (2017, January 11\u201314). An Improved P2P file System scheme based on IPFS and Blockchain. Proceedings of the IEEE International Conference on Big Data, Boston, MA, USA.","DOI":"10.1109\/BigData.2017.8258226"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"3976093","DOI":"10.1155\/2018\/3976093","article-title":"Performance Analysis of Hyperledger Fabric Platforms","volume":"2018","author":"Nasir","year":"2018","journal-title":"Secur. Commun. 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