{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,7]],"date-time":"2026-03-07T18:06:38Z","timestamp":1772906798688,"version":"3.50.1"},"reference-count":38,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2015,10,22]],"date-time":"2015-10-22T00:00:00Z","timestamp":1445472000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Sciex-NMSch","award":["13.121"],"award-info":[{"award-number":["13.121"]}]},{"name":"SAFESENS ENIAC","award":["621272"],"award-info":[{"award-number":["621272"]}]},{"name":"EU Horizon 2020","award":["649849"],"award-info":[{"award-number":["649849"]}]},{"name":"EU Horizon 2020","award":["644672"],"award-info":[{"award-number":["644672"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. In constrained devices of the Internet of Things ecosystem, high entropy random number generators are hard to achieve due to hardware limitations. For the purpose of the random number generation in constrained devices, this work proposes a solution based on the least-significant bits concatenation entropy harvesting method. As a potential source of entropy, on-board integrated sensors (i.e., temperature, humidity and two different light sensors) have been analyzed. Additionally, the costs (i.e., time and memory consumption) of the presented approach have been measured. The results obtained from the proposed method with statistical fine tuning achieved a Shannon entropy of around 7.9 bits per byte of data for temperature and humidity sensors. The results showed that sensor-based random number generators are a valuable source of entropy with very small RAM and Flash memory requirements for constrained devices of the Internet of Things.<\/jats:p>","DOI":"10.3390\/s151026838","type":"journal-article","created":{"date-parts":[[2015,10,26]],"date-time":"2015-10-26T04:12:04Z","timestamp":1445832724000},"page":"26838-26865","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Harvesting Entropy for Random Number Generation for Internet of Things Constrained Devices Using On-Board Sensors"],"prefix":"10.3390","volume":"15","author":[{"given":"Marcin","family":"Pawlowski","sequence":"first","affiliation":[{"name":"Institute of Information Systems, University of Applied Sciences Western Switzerland (HES-SO), Sierre 3960, Switzerland"},{"name":"Department of Information Technologies, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Krakow 30-348, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Antonio","family":"Jara","sequence":"additional","affiliation":[{"name":"Institute of Information Systems, University of Applied Sciences Western Switzerland (HES-SO), Sierre 3960, Switzerland"},{"name":"Research and Development Department, HOP Ubiquitous, 30562 Ceuti, Murcia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maciej","family":"Ogorzalek","sequence":"additional","affiliation":[{"name":"Department of Information Technologies, Faculty of Physics, Astronomy and Applied Computer Science, Jagiellonian University, Krakow 30-348, Poland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2015,10,22]]},"reference":[{"key":"ref_1","unstructured":"Patrick, G., and Friess, P. (2009). The Internet of Things\u2014Strategic Reseach Roadmap (2009), European Commission\u2014Information Society and Media DG."},{"key":"ref_2","unstructured":"Union, I.T. (2005). The Internet of Things\u2014Executive Summary, ITU. ITU Internet Reports 2005."},{"key":"ref_3","unstructured":"Cisco about Internet of Things. Available online: http:\/\/www.eetimes.com\/electronics-news\/4409928\/Cisco-sees\u201314-trillion-opportunity-in-Internet-of-Things."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1007\/s00779-006-0076-5","article-title":"Homes that make us smart","volume":"11","author":"Taylor","year":"2007","journal-title":"Pers. Ubiquitous Comput."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1109\/JSAC.2009.090506","article-title":"Remote patient monitoring service using heterogeneous wireless access networks: Architecture and optimization","volume":"27","author":"Niyato","year":"2009","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1007\/s11277-011-0385-5","article-title":"Security Challenges in the IP-based Internet of Things","volume":"61","author":"Heer","year":"2011","journal-title":"Wirel. Pers. Commun."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2266","DOI":"10.1016\/j.comnet.2012.12.018","article-title":"On the features and challenges of security and privacy in distributed internet of things","volume":"57","author":"Roman","year":"2013","journal-title":"Comput. Netw."},{"key":"ref_8","first-page":"155","article-title":"Editorial on Internet of Things: Standards, Technology and Applications","volume":"13","author":"Yang","year":"2013","journal-title":"Int. J. Ad Hoc Ubiquitous Comput."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Rescola, E., and Modadugu, N. Datagram Transport Layer Security (DTLS), Request for Comments No. 4347, IETF: 2006.","DOI":"10.17487\/rfc4347"},{"key":"ref_10","unstructured":"IETF Datagram Transport Layer Security for the Internet of Things (DTLS-IoT) Working Group. Available online: https:\/\/datatracker.ietf.org\/wg\/dice\/charter\/."},{"key":"ref_11","unstructured":"IETF Authentication and Authorization for Constrained Environments (ACE) Working Group. Available online: https:\/\/datatracker.ietf.org\/wg\/ace\/charter\/."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1210","DOI":"10.3390\/s130101210","article-title":"A network access control framework for 6LoWPAN networks","volume":"13","author":"Oliveira","year":"2013","journal-title":"Sensors"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Garcia-Morchon, O., Keoh, S., Kumar, S., Moreno-S\u00c3\u0105nchez, P., Vidal-Meca, F., and Ziegeldorf, J. (2013, January 17\u201319). Securing the IP-based internet of things with HIP and DTLS. Proceedings of the Sixth ACM Conference on Security and Privacy in Wireless and Mobile Networks, Budapest, Hungary.","DOI":"10.1145\/2462096.2462117"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"14888","DOI":"10.3390\/s131114888","article-title":"PANATIKI: A Network Access Control Implementation Based on PANA for IoT Devices","volume":"13","author":"Sanchez","year":"2013","journal-title":"Sensors"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1849","DOI":"10.1007\/s11277-014-2048-9","article-title":"Wireless sensor networks in IPv4\/IPv6 transition scenarios","volume":"78","author":"Oliveira","year":"2014","journal-title":"Wirel. Pers. Commun."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1002\/cpe.2850","article-title":"Denial of service mitigation approach for IPv6-enabled smart object networks","volume":"25","author":"Oliveira","year":"2013","journal-title":"Concurr. Comput. Pract. Exp."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"De Assis, M.V., Rodrigues, J.J., and Lemes Proenca, M. (2013, January 18\u201320). A hybrid approach for anomaly detection on large-scale networks using HWDS and entropy. Proceedings of the 2013 21st International Conference on Software, Telecommunications and Computer Networks (SoftCOM), Primosten, Croatia.","DOI":"10.1109\/SoftCOM.2013.6671845"},{"key":"ref_18","unstructured":"Eastlake, D., Schiller, J., and Crocker, S. Randomness Requirements for Security. Available online: http:\/\/tools.ietf.org\/html\/rfc4086."},{"key":"ref_19","unstructured":"Barker, E.B., and Kelsey, J.M. (2012). Recommendation for Random Bit Generator (RBG) Constructions."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Pawlowski, M.P., Jara, A.J., and Ogorzalek, M.J. (2014, January 2\u20134). Extending Extensible Authentication Protocol over IEEE 802.15.4 networks. Proceedings of the 8th International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing, IMIS-2014, Birmingham, UK.","DOI":"10.1109\/IMIS.2014.93"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"690","DOI":"10.1109\/JSAC.2015.2393436","article-title":"Towards a Lightweight Authentication and Authorization Framework for Smart Objects","volume":"33","author":"Pawlowski","year":"2015","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"21478","DOI":"10.3390\/s150921478","article-title":"Optimized ECC Implementation for Secure Communication between Heterogeneous IoT Devices","volume":"15","author":"Marin","year":"2015","journal-title":"Sensors"},{"key":"ref_23","unstructured":"TelosB Brekley Site. Available online: http:\/\/openwsn.berkley.edu\/wiki\/TelosB."},{"key":"ref_24","unstructured":"ContikiOS Project Web Site. Available online: http:\/\/www.contiki-os.org\/."},{"key":"ref_25","unstructured":"Elaine, B., and John, K. (2012). Recommendation for the Entropy Sources Used for Random Bit Generation. Draft NIST Spec. Publ., 800-90B."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Hennebert, C., Hossayni, H., and Lauradoux, C. (2013, January 17\u201319). Entropy harvesting from physical sensors. Proceedings of the 6th ACM Conference on Security and Privacy in Wireless and Mobile Networks (WISEC\u201913), Budapest, Hungary.","DOI":"10.1145\/2462096.2462122"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Francillon, A., and Castelluccia, C. (2007, January 16\u201320). TinyRNG: A cryptographic random number generator for wireless sensors network nodes. Proceedings of the 5th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks and Workshops (WiOpt\u201907), Limassol, Ciprus.","DOI":"10.1109\/WIOPT.2007.4480051"},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Fabbri, M., and Callegari, S. (2014, January 7\u201310). Very low cost entropy source based on chaotic dynamics retrofittable on networked devices to prevent RNG attacks. Proceedings of the 2014 21st IEEE International Conference on Electronics, Circuits and Systems (ICECS), Marseille, France.","DOI":"10.1109\/ICECS.2014.7049950"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1109\/TC.2007.250627","article-title":"A provably secure true random number generator with built-in tolerance to active attacks","volume":"56","author":"Sunar","year":"2007","journal-title":"IEEE Trans. Comput."},{"key":"ref_30","unstructured":"Hausser, J., and Strimmer, K. R Entropy Package. Available online: http:\/\/strimmerlab.org\/software\/entropy\/."},{"key":"ref_31","unstructured":"The R Project for Statistical Computing. Available online: http:\/\/www.r-project.org\/."},{"key":"ref_32","unstructured":"Jun, B., and Kocher, P. (1999). The Intel Random Number Generator, Cryptography Research Inc.. Cryptography Research Inc. White Paper."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Hund, R., Willems, C., and Holz, T. (2013, January 19\u201322). Practical timing side channel attacks against kernel space ASLR. Proceedings of the 2013 IEEE Symposium on Security and Privacy (SP), Berkeley, CA, USA.","DOI":"10.1109\/SP.2013.23"},{"key":"ref_34","unstructured":"Kocher, P., Jaffe, J., and Jun, B. (1999). Advances in Cryptology\u2014CRYPTO\u201999, Springer."},{"key":"ref_35","unstructured":"Agrawal, D., Archambeault, B., Rao, J.R., and Rohatgi, P. (2003). Cryptographic Hardware and Embedded Systems-CHES 2002, Springer."},{"key":"ref_36","unstructured":"Genkin, D., Pipman, I., and Tromer, E. (2014). Cryptographic Hardware and Embedded Systems\u2014CHES 2014, Springer."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Rukhin, A., Soto, J., Nechvatal, J., Smid, M., and Barker, E. (2001). A Statistical Test Suite for Random and Pseudorandom Number Generators for Cryptographic Applications, NIST. Technical Report, DTIC Document.","DOI":"10.6028\/NIST.SP.800-22"},{"key":"ref_38","unstructured":"Killmann, W., and Schindler, W. (2001). T-Systems Debis Systemhaus Information Security Services and Bundesamt f\u00fcr Sicherheit in der Informationstechnik (BSI), BSI. Technical Report."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/10\/26838\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T20:50:39Z","timestamp":1760215839000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/15\/10\/26838"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,10,22]]},"references-count":38,"journal-issue":{"issue":"10","published-online":{"date-parts":[[2015,10]]}},"alternative-id":["s151026838"],"URL":"https:\/\/doi.org\/10.3390\/s151026838","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,10,22]]}}}