{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,4]],"date-time":"2026-10-04T12:54:24Z","timestamp":1791118464770,"version":"4.1.0"},"reference-count":74,"publisher":"Association for Computing Machinery (ACM)","issue":"1","license":[{"start":{"date-parts":[[2013,12,1]],"date-time":"2013-12-01T00:00:00Z","timestamp":1385856000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.acm.org\/publications\/policies\/copyright_policy#Background"}],"funder":[{"DOI":"10.13039\/501100002920","name":"Research Grants Council, University Grants Committee, Hong Kong","doi-asserted-by":"publisher","award":["HKU 715108E"],"award-info":[{"award-number":["HKU 715108E"]}],"id":[{"id":"10.13039\/501100002920","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":["ACM Trans. Web"],"published-print":{"date-parts":[[2013,12]]},"abstract":"<jats:p>With the rapid growth of applications which generate timestamped sequences (click streams, GPS trajectories, RFID sequences), sequence anonymization has become an important problem, in that should such data be published or shared. Existing trajectory anonymization techniques disregard the importance of time or the sensitivity of events. This article is the first, to our knowledge, thorough study on time-stamped event sequence anonymization. We propose a novel and tunable generalization framework tailored to event sequences. We generalize time stamps using time intervals and events using a taxonomy which models the domain semantics. We consider two scenarios: (i) sharing the data with a single receiver (the SSR setting), where the receiver\u2019s background knowledge is confined to a set of time stamps and time generalization suffices, and (ii) sharing the data with colluding receivers (the SCR setting), where time generalization should be combined with event generalization. For both cases, we propose appropriate anonymization methods that prevent both user identification and event prediction. To achieve computational efficiency and scalability, we propose optimization techniques for both cases using a utility-based index, compact summaries, fast to compute bounds for utility, and a novel taxonomy-aware distance function. Extensive experiments confirm the effectiveness of our approach compared with state of the art, in terms of information loss, range query distortion, and preserving temporal causality patterns. Furthermore, our experiments demonstrate efficiency and scalability on large-scale real and synthetic datasets.<\/jats:p>","DOI":"10.1145\/2532643","type":"journal-article","created":{"date-parts":[[2014,1,6]],"date-time":"2014-01-06T20:42:39Z","timestamp":1389040959000},"page":"1-53","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":8,"title":["Efficient Time-Stamped Event Sequence Anonymization"],"prefix":"10.1145","volume":"8","author":[{"given":"Reza","family":"Sherkat","sequence":"first","affiliation":[{"name":"The University of Hong Kong"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jing","family":"Li","sequence":"additional","affiliation":[{"name":"The University of Hong Kong"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nikos","family":"Mamoulis","sequence":"additional","affiliation":[{"name":"The University of Hong Kong"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"320","published-online":{"date-parts":[[2013,12]]},"reference":[{"key":"e_1_2_1_1_1","doi-asserted-by":"publisher","DOI":"10.1109\/ICDE.2008.4497446"},{"key":"e_1_2_1_2_1","volume-title":"Proceedings of the SIAM International Conference on Data Mining (SDM).","author":"Aggarwal C. C.","unstructured":"Aggarwal , C. C. and Yu , P. S . 2007a. On anonymization of string data . In Proceedings of the SIAM International Conference on Data Mining (SDM). Aggarwal, C. C. and Yu, P. S. 2007a. On anonymization of string data. In Proceedings of the SIAM International Conference on Data Mining (SDM)."},{"key":"e_1_2_1_3_1","volume-title":"Proceedings of the SIAM International Conference on Data Mining (SDM).","author":"Aggarwal C. C.","unstructured":"Aggarwal , C. C. and Yu , P. S . 2007b. On privacy-preservation of text and sparse binary data with sketches . In Proceedings of the SIAM International Conference on Data Mining (SDM). Aggarwal, C. C. and Yu, P. S. 2007b. On privacy-preservation of text and sparse binary data with sketches. In Proceedings of the SIAM International Conference on Data Mining (SDM)."},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1145\/1148170.1148175"},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.1145\/335191.335438"},{"key":"e_1_2_1_6_1","doi-asserted-by":"publisher","DOI":"10.1145\/237814.237823"},{"key":"e_1_2_1_7_1","unstructured":"Barbaro M. and Zeller T. 2006. A face is exposed for AOL searcher no. 4417749. The New York Times. August 9.  Barbaro M. and Zeller T. 2006. A face is exposed for AOL searcher no. 4417749. The New York Times . August 9."},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.1109\/ICDE.2005.42"},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.1145\/2031331.2031336"},{"key":"e_1_2_1_10_1","first-page":"19","article-title":"Generating traffic data","volume":"26","author":"Brinkhoff T.","year":"2003","unstructured":"Brinkhoff , T. 2003 . Generating traffic data . IEEE Data Eng. Bullet. 26 , 2, 19 -- 25 . Brinkhoff, T. 2003. Generating traffic data. IEEE Data Eng. Bullet. 26, 2, 19--25.","journal-title":"IEEE Data Eng. Bullet."},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1145\/2382196.2382263"},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1145\/2339530.2339564"},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ins.2011.07.035"},{"key":"e_1_2_1_14_1","doi-asserted-by":"publisher","DOI":"10.1007\/11957454_23"},{"key":"e_1_2_1_15_1","doi-asserted-by":"publisher","DOI":"10.1145\/2031331.2031335"},{"key":"e_1_2_1_16_1","volume-title":"Proceedings of the 23rd International Conference on VLDB (VLDB).","author":"Ciaccia P.","unstructured":"Ciaccia , P. , Patella , M. , and Zezula , P . 1997. M-tree: An efficient access method for similarity search in metric spaces . In Proceedings of the 23rd International Conference on VLDB (VLDB). Ciaccia, P., Patella, M., and Zezula, P. 1997. M-tree: An efficient access method for similarity search in metric spaces. In Proceedings of the 23rd International Conference on VLDB (VLDB)."},{"key":"e_1_2_1_17_1","doi-asserted-by":"publisher","DOI":"10.14778\/1920841.1920972"},{"key":"e_1_2_1_18_1","doi-asserted-by":"publisher","DOI":"10.1145\/990301.990304"},{"key":"e_1_2_1_19_1","doi-asserted-by":"publisher","DOI":"10.1145\/1989323.1989347"},{"key":"e_1_2_1_20_1","doi-asserted-by":"publisher","DOI":"10.1145\/1390334.1390392"},{"key":"e_1_2_1_21_1","doi-asserted-by":"publisher","DOI":"10.1007\/11681878_14"},{"key":"e_1_2_1_22_1","doi-asserted-by":"publisher","DOI":"10.1145\/355744.355745"},{"key":"e_1_2_1_23_1","doi-asserted-by":"publisher","DOI":"10.1145\/1529282.1529626"},{"key":"e_1_2_1_24_1","doi-asserted-by":"publisher","DOI":"10.1145\/1401890.1401926"},{"key":"e_1_2_1_25_1","doi-asserted-by":"publisher","DOI":"10.5555\/1556406.1556408"},{"key":"e_1_2_1_26_1","volume-title":"Proceedings of the 33rd International Conference on VLDB (VLDB).","author":"Ghinita G.","unstructured":"Ghinita , G. , Karras , P. , Kalnis , P. , and Mamoulis , N . 2007. Fast data anonymization with low information loss . In Proceedings of the 33rd International Conference on VLDB (VLDB). Ghinita, G., Karras, P., Kalnis, P., and Mamoulis, N. 2007. Fast data anonymization with low information loss. In Proceedings of the 33rd International Conference on VLDB (VLDB)."},{"key":"e_1_2_1_27_1","doi-asserted-by":"publisher","DOI":"10.1145\/1376616.1376631"},{"key":"e_1_2_1_28_1","doi-asserted-by":"publisher","DOI":"10.1145\/1718487.1718513"},{"key":"e_1_2_1_29_1","unstructured":"Google. 2011. Google privacy FAQ. http:\/\/www.google.com\/privacy\/faq.html.  Google. 2011. Google privacy FAQ. http:\/\/www.google.com\/privacy\/faq.html."},{"key":"e_1_2_1_30_1","doi-asserted-by":"publisher","DOI":"10.1109\/TKDE.2011.26"},{"key":"e_1_2_1_31_1","doi-asserted-by":"publisher","DOI":"10.1145\/602259.602266"},{"key":"e_1_2_1_32_1","volume-title":"Proceedings of the 31st International Conference on VLDB (VLDB).","author":"Hadjieleftheriou M.","unstructured":"Hadjieleftheriou , M. , Kollios , G. , Bakalov , P. , and Tsotras , V. J . 2005. Complex spatio-temporal pattern queries . In Proceedings of the 31st International Conference on VLDB (VLDB). Hadjieleftheriou, M., Kollios, G., Bakalov, P., and Tsotras, V. J. 2005. Complex spatio-temporal pattern queries. In Proceedings of the 31st International Conference on VLDB (VLDB)."},{"key":"e_1_2_1_33_1","doi-asserted-by":"publisher","DOI":"10.14778\/1687627.1687733"},{"key":"e_1_2_1_34_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-642-29038-1_26"},{"key":"e_1_2_1_35_1","volume-title":"Proceedings of the 29th International Conference on VLDB (VLDB).","author":"Iwuchukwu T.","unstructured":"Iwuchukwu , T. and Naughton , J. F . 2007. K-anonymization as spatial indexing: Toward scalable and incremental anonymization . In Proceedings of the 29th International Conference on VLDB (VLDB). Iwuchukwu, T. and Naughton, J. F. 2007. K-anonymization as spatial indexing: Toward scalable and incremental anonymization. In Proceedings of the 29th International Conference on VLDB (VLDB)."},{"key":"e_1_2_1_36_1","doi-asserted-by":"publisher","DOI":"10.1145\/1321440.1321573"},{"key":"e_1_2_1_37_1","volume-title":"Proceedings of the International Conference on Pervasive Services.","author":"Kido H.","unstructured":"Kido , H. , Yanagisawa , Y. , and Satoh , T . 2005. An anonymous communication technique using dummies for location-based services . In Proceedings of the International Conference on Pervasive Services. Kido, H., Yanagisawa, Y., and Satoh, T. 2005. An anonymous communication technique using dummies for location-based services. In Proceedings of the International Conference on Pervasive Services."},{"key":"e_1_2_1_38_1","doi-asserted-by":"publisher","DOI":"10.1145\/1559845.1559861"},{"key":"e_1_2_1_39_1","doi-asserted-by":"publisher","DOI":"10.1145\/1142473.1142499"},{"key":"e_1_2_1_40_1","doi-asserted-by":"publisher","DOI":"10.1145\/1989323.1989345"},{"key":"e_1_2_1_41_1","doi-asserted-by":"publisher","DOI":"10.1145\/1721654.1721677"},{"key":"e_1_2_1_42_1","doi-asserted-by":"publisher","DOI":"10.1145\/1526709.1526733"},{"key":"e_1_2_1_43_1","doi-asserted-by":"publisher","DOI":"10.1214\/aoms\/1177729694"},{"key":"e_1_2_1_44_1","doi-asserted-by":"publisher","DOI":"10.1109\/ICDE.2006.101"},{"key":"e_1_2_1_45_1","volume-title":"Proceedings of the 23rd International Conference on Data Engineering (ICDE).","author":"Li N.","unstructured":"Li , N. , Li , T. , and Venkatasubramanian , S . 2007. T-closeness: Privacy beyond K-anonymity and L-diversity . In Proceedings of the 23rd International Conference on Data Engineering (ICDE). Li, N., Li, T., and Venkatasubramanian, S. 2007. T-closeness: Privacy beyond K-anonymity and L-diversity. In Proceedings of the 23rd International Conference on Data Engineering (ICDE)."},{"key":"e_1_2_1_46_1","doi-asserted-by":"publisher","DOI":"10.1109\/ICDE.2006.1"},{"key":"e_1_2_1_47_1","doi-asserted-by":"publisher","DOI":"10.1109\/ICDE.2008.4497436"},{"key":"e_1_2_1_48_1","doi-asserted-by":"publisher","DOI":"10.14778\/1988776.1988780"},{"key":"e_1_2_1_49_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-3-642-34601-9_12"},{"key":"e_1_2_1_50_1","doi-asserted-by":"publisher","DOI":"10.1023\/A:1009748302351"},{"key":"e_1_2_1_51_1","doi-asserted-by":"publisher","DOI":"10.1145\/1935826.1935840"},{"key":"e_1_2_1_52_1","doi-asserted-by":"publisher","DOI":"10.1145\/1055558.1055591"},{"key":"e_1_2_1_53_1","volume-title":"Proceedings of the 28th International Conference on VLDB (VLDB).","author":"Mokbel M. F.","unstructured":"Mokbel , M. F. , Chow , C.-Y. , and Aref , W. G . 2006. The new casper: Query processing for location services without compromising privacy . In Proceedings of the 28th International Conference on VLDB (VLDB). Mokbel, M. F., Chow, C.-Y., and Aref, W. G. 2006. The new casper: Query processing for location services without compromising privacy. In Proceedings of the 28th International Conference on VLDB (VLDB)."},{"key":"e_1_2_1_54_1","first-page":"27","article-title":"Movement data anonymity through generalization","volume":"3","author":"Monreale A.","year":"2010","unstructured":"Monreale , A. , Andrienko , G. , Andrienko , N. , Giannotti , F. , Pedreschi , D. , Rinzivillo , S. , and Wrobe , S. 2010 . Movement data anonymity through generalization . Trans. Data Privacy 3 , 2, 27 -- 31 . Monreale, A., Andrienko, G., Andrienko, N., Giannotti, F., Pedreschi, D., Rinzivillo, S., and Wrobe, S. 2010. Movement data anonymity through generalization. Trans. Data Privacy 3, 2, 27--31.","journal-title":"Trans. Data Privacy"},{"key":"e_1_2_1_55_1","doi-asserted-by":"publisher","DOI":"10.1109\/69.908985"},{"key":"e_1_2_1_56_1","doi-asserted-by":"publisher","DOI":"10.5555\/1556406.1556410"},{"key":"e_1_2_1_57_1","doi-asserted-by":"publisher","DOI":"10.14778\/1920841.1920918"},{"key":"e_1_2_1_58_1","unstructured":"Papoulis A. and Pillai S. U. 2002. Probability Random Variables and Stochastic Processes. McGraw Hill.  Papoulis A. and Pillai S. U. 2002. Probability Random Variables and Stochastic Processes . McGraw Hill."},{"key":"e_1_2_1_59_1","doi-asserted-by":"publisher","DOI":"10.1109\/69.971193"},{"key":"e_1_2_1_60_1","doi-asserted-by":"publisher","DOI":"10.1145\/276304.276319"},{"key":"e_1_2_1_61_1","doi-asserted-by":"publisher","DOI":"10.14778\/1453856.1453953"},{"key":"e_1_2_1_62_1","doi-asserted-by":"publisher","DOI":"10.1142\/S0218488502001648"},{"key":"e_1_2_1_63_1","doi-asserted-by":"publisher","DOI":"10.1109\/MDM.2008.29"},{"key":"e_1_2_1_64_1","doi-asserted-by":"publisher","DOI":"10.14778\/1453856.1453874"},{"key":"e_1_2_1_65_1","doi-asserted-by":"publisher","DOI":"10.14778\/2336664.2336668"},{"key":"e_1_2_1_66_1","volume-title":"Proceedings of the 17th International Conference on Machine Learning (ICML).","author":"Wagstaff K.","unstructured":"Wagstaff , K. and Cardie , C . 2000. Clustering with instance-level constraints . In Proceedings of the 17th International Conference on Machine Learning (ICML). Wagstaff, K. and Cardie, C. 2000. Clustering with instance-level constraints. In Proceedings of the 17th International Conference on Machine Learning (ICML)."},{"key":"e_1_2_1_67_1","doi-asserted-by":"publisher","DOI":"10.1089\/cmb.1994.1.337"},{"key":"e_1_2_1_68_1","volume-title":"Proceedings of the 29th International Conference on VLDB (VLDB).","author":"Wong R. C.-W.","unstructured":"Wong , R. C.-W. , Fu , A. W. , Wang , K. , and Pei , J . 2007. Minimality attack in privacy preserving data publishing . In Proceedings of the 29th International Conference on VLDB (VLDB). Wong, R. C.-W., Fu, A. W., Wang, K., and Pei, J. 2007. Minimality attack in privacy preserving data publishing. In Proceedings of the 29th International Conference on VLDB (VLDB)."},{"key":"e_1_2_1_69_1","volume-title":"Proceedings of the 28th International Conference on VLDB (VLDB).","author":"Xiao X.","unstructured":"Xiao , X. and Tao , Y . 2006. Anatomy: Simple and effective privacy preservation . In Proceedings of the 28th International Conference on VLDB (VLDB). Xiao, X. and Tao, Y. 2006. Anatomy: Simple and effective privacy preservation. In Proceedings of the 28th International Conference on VLDB (VLDB)."},{"key":"e_1_2_1_70_1","volume-title":"Proceedings of the 26th International Conference on Data Engineering (ICDE).","author":"Xiao X.","unstructured":"Xiao , X. , Wang , G. , and Gehrke , J . 2010. Differential privacy via wavelet transforms . In Proceedings of the 26th International Conference on Data Engineering (ICDE). Xiao, X., Wang, G., and Gehrke, J. 2010. Differential privacy via wavelet transforms. In Proceedings of the 26th International Conference on Data Engineering (ICDE)."},{"key":"e_1_2_1_71_1","doi-asserted-by":"publisher","DOI":"10.1145\/1150402.1150504"},{"key":"e_1_2_1_72_1","doi-asserted-by":"publisher","DOI":"10.1145\/1401890.1401982"},{"key":"e_1_2_1_73_1","doi-asserted-by":"publisher","DOI":"10.1145\/1516360.1516370"},{"key":"e_1_2_1_74_1","doi-asserted-by":"publisher","DOI":"10.14778\/2428536.2428539"}],"container-title":["ACM Transactions on the Web"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/2532643","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/2532643","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T20:22:05Z","timestamp":1750278125000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/2532643"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2013,12]]},"references-count":74,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2013,12]]}},"alternative-id":["10.1145\/2532643"],"URL":"https:\/\/doi.org\/10.1145\/2532643","relation":{},"ISSN":["1559-1131","1559-114X"],"issn-type":[{"value":"1559-1131","type":"print"},{"value":"1559-114X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2013,12]]},"assertion":[{"value":"2012-09-01","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2013-09-01","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2013-12-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}