{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,11]],"date-time":"2026-01-11T14:55:00Z","timestamp":1768143300571,"version":"3.49.0"},"reference-count":41,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2022,2,12]],"date-time":"2022-02-12T00:00:00Z","timestamp":1644624000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>An increased pattern of hidden Internet of Things (IoT) devices has been observed. Due to the increased number of security attacks, a large number of IoT devices are disappearing from the public internet. Operating blockchain operations in such ad hoc connectivity becomes challenging. However, multiple past studies have pointed towards IOTA Distributed Ledger Technology (DLT) that closely caters to offline blockchain use cases. However, there has been little to no empirical study or introduction to time bounds on transaction confirmation. Therefore, this study explains what provisions the existing IOTA blockchain has to accommodate the increased pattern of hidden IoT devices, and if IOTA is truly sufficient as a solution. In summary, we approach research questions by analyzing the studies that explore the trend of offline IoT devices and evaluating the relevance of offline blockchains, assessing the IOTA specification and codebase around offline transaction-making capabilities and pointing out some bounds that IOTA blockchain nodes must follow towards incoming transactions. Furthermore, we confirm by experimental runs that outside and within the tight time bounds transactions in offline Tangle can become stale and not get confirmed, and the effective time-bound can be even less. Realizing the need for a better offline blockchain scalability solution.<\/jats:p>","DOI":"10.3390\/s22041411","type":"journal-article","created":{"date-parts":[[2022,2,13]],"date-time":"2022-02-13T20:34:45Z","timestamp":1644784485000},"page":"1411","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Offline Scaling of IoT Devices in IOTA Blockchain"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7733-5023","authenticated-orcid":false,"given":"Abhimanyu","family":"Rawat","sequence":"first","affiliation":[{"name":"Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0583-7929","authenticated-orcid":false,"given":"Vanesa","family":"Daza","sequence":"additional","affiliation":[{"name":"Department of Information and Communication Technologies, Universitat Pompeu Fabra, 08018 Barcelona, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9208-4023","authenticated-orcid":false,"given":"Matteo","family":"Signorini","sequence":"additional","affiliation":[{"name":"NOKIA Bell Labs, 91620 Nozay, France"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"8076","DOI":"10.1109\/JIOT.2019.2920987","article-title":"Blockchain for Internet of Things: A Survey","volume":"6","author":"Dai","year":"2019","journal-title":"IEEE Internet Things J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1145\/98163.98167","article-title":"Implementing fault-tolerant services using the state machine approach: A tutorial","volume":"22","author":"Schneider","year":"1990","journal-title":"ACM Comput. 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