CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '9135c20d6805fd95',cH: 'e9RVeCUpqEpWnlFokFaiqG7W4mfI_2rJeS_EKNF3ZQ0-1739795104-1.2.1.1-nPrKIB4rXS4T_55F1GhngMnxW1ITS6QLVQqxZs9vHTh7gskL9xGrNa78ieJ4xXjN',cUPMDTk: "\/abstracts\/search?q=phone%20number%20spoofing&__cf_chl_tk=EJXdB_guOAPxMr5rHH9BTHTV1nZCe7fNFUyGpjiz9e4-1739795104-1.0.1.1-.fvkz.pXBlOAcq0yxVFH3.sQDxtU9916fdCZyl5Lmfk",cFPWv: 'b',cITimeS: '1739795104',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=phone%20number%20spoofing&__cf_chl_f_tk=EJXdB_guOAPxMr5rHH9BTHTV1nZCe7fNFUyGpjiz9e4-1739795104-1.0.1.1-.fvkz.pXBlOAcq0yxVFH3.sQDxtU9916fdCZyl5Lmfk",md: "NtH5Km0.USdSwVnAqLkXEFLkqQSQMhGph66bvo_apRQ-1739795104-1.2.1.1-x1vxYcubTXWmR56SrGjE7mM.KtWvHFRqNRuAqNrSfnbVRgRzVGO.7e.0KCGfCjWEedSyrBqo7GC1MR9A68uWeW.iuYhG00HDjmsHqCFINvntTH6V5hWP4Sf_KunUCkCv9FsGmt2Vmtb.8ol2nQF4HYpdRgsCf7folDf8GGs8nXerirgFfr50gmNwyEdRpE9vMqutYAyVKA2kvaPnneybBQcRLiyJ1x7ghfddfxS.YaqmnaOHmq1hY59HmA91CSLeNpBwb5tCl8VCo8O7HSv.YNyuC1tjfCyBkZeSZF.ajoJF9nWMBtSvmAC0mAHYKCyBLs8F6HZmHKUAilHYJDv0Fbk_dj7TgFXnrDpokQ3e5fNM6UI61YKHuc9X5sFt7r.NXNndrCRnuLX43Wn_jYRUzzCFaZEpAcsAbqNdz.uIo.INlomEnGZg_4leAUD6nNA6y8SWlxXXIzNo6zE9k6Snb3ajBTHXs0bhVo.K3J15WO4niKS6ljngrquwHM1gGVyAY1wyDwxS4fOGGeweKnOe0upaZ2N02NdXfArgnHjgETtdMyxR.SA2kzkBzgax38uUGpPlkxnfK.4A7jcy3Nr1iR0r1bxa7iRONFaSyruAftpK6TDBR_xjTfq3eyxMms9_ibDCrlJgowg82.G6KDNLWpvdbSNOyDtOAdfMiV7ub6_8OR3XFXhsMjE7KBNIxgII2L5jFxWNGS07x31usWkLTx5OV06l.Q.NgxkgUbMQi1kqgbU0CNpbL5_GQBf8rJoeDvhNMII5YMB4C1ly_IpiB.b5LNcHawKeU.Od4dymAjhZXFyU4SKRvWQ9tA0qBeoNRlt5_.5B7N8q2Lf6wCJSVdE1cY9lCE.7oj7C75fopqF7wkI7xjWeqd4y0GP1eNOpHyp2gbJMnAfhE01McvMny0KRrgOIqE2pbVHiucv2dEDD3V5va5.HQr7Q179.dPLEA9E7a4IdHjU_GG98kmrS1isd6Q4f4uGYCFi4l2fiOedAJBourIvIKQeiHmGti3Oh0UbPtglgDDSvBSVTenh9asYoDhL4LqAijoDsRK4W8xnkhDXzQqNsFINw7MqWaNzl8_ucCCXiGsox6fybLswaD1X7CewOSRZWvOh5b1Ig0j7lY6t4TkgkIbti_mlvsu44Tz7t.HKIzeKRMVY8CDhYrliI6n24EGET.XVM4tXzCOPBhAeOaqPW5W.JTwnANZ5soIfizcUoR6DnGD0__NV87YAJnby8.NHkiJPwdr.h8SZDK_XHeCCaKPIfBtEAfy1MQbRk1o9NMBT8cs0P7xnhOEZ7G.9CuEsX93LdKDRgdZdSYUK8pEb8CIASxjaswem0F_m1LVRzjVCI6gDBXCt9pXx7i3oGOJK05OFlskTz_O12wfQ9BiCegR1EXLqZ4.tkOV8al_0G3uvJGSvjRKh5fjXsEMF4P94n22pXqCuilFiD.12eruTbfbgmUIYtzRQnXQt3nJUeJSvIpEAWn4i4Zi0iOyg_QjSaNOAlz1E3NDRD4r12k7x0G3nPlB34jgW9U_Bg9EWcwG67wMBbhorJO3olS3GvcaOk47LBwH0aI5Bi229QiBi_3kwzBATfc5DMfW5CJjJtTsTNT4bLPVEyADoMYN7_f2.W0kf4266Phs5h6wtOG6Idn_riGx.wx_kaHgNSCUIiyxgiL1gDiCLtFgHslg699zTIkT8U.46_WIyqfUXiShP_gyzLOxCMtKbBK2USex8eSnjSxcHJUjxpVmmxwj0YCjAtywrpU4ZqnFhO5AKS3XE.KLOXE5FdsoGTBsg1BkUoPKrWIgkIxmCHTekuDo2qHVu3aRFlAxcDu27szmSK0Ck5rh9DzGTkN.0FNwKFvrqMA6Kzzi8YurLe_3HUIgpbUtSVGCIy1YualEasl0IKRMgthwImIK.alKbEzc4b3o5yP..FJdDKYW3491fWgmGZPpykK92XK7g8L19ELaTcvDdSrsRtpUI0M6Wf",mdrd: "aOeDxQZVsOPb4AMpDbG091k17e_pMBL_RvvXqyaDiJc-1739795104-1.2.1.1-RdKn08xJ9LhcieY0S42VMf2tdkvxDhwAM6Lj47BZQ6zTLiFZpmVEjEPkA0H7GAsVyOcdvySpdc1j_867O1q1iAUaCmhdKxZYcmAqnEHibVoqSb14nnqvFfqkg9KVLvQZFDSNg3lUOL9rRb8O_KLcOGvRfHj3H8upp0IHu1mijq1oTqTic5UwgxdxZAWmGtMo4yNLvu2lWyCIJPEivmWcIvqDUUw4p6rHYQYQHPNkKNDVgfoEuH67UIq3k8dU16vrqXOPqSfXElY17sa6FQid7QRzwF4carDFQKYq3J1_VPVG6rrUjxy.DyXJEA8Ks2F7bN6AM6KFd8_UhCMFcR9KFGjbez8ByZDbyhh_2d5Bs8.WhlgWLG4tCdEPxwVPsAfMR9gqocdSXHa0PTndoMYqm1B6gnElMiRTq2F6Qxu8fZBubdbL91qDbZdQF4YaA5dXmJp8H2Q9dK6BDeFsNk2ds6NQIaXJmnzjvoEhyrAgR8MhcYjlJhNI3mbt6dPreTeRlXy.IBTnbixLfdaByxUWwxffu1zY91_UjbsBBkjk8IyN2LYSVDdxMzDyazd51Bec_8HUSAdVQ5buklcoGHY13pN7fuQjPJEJsjMfCE1YqDTGKJsXSKolbYl.qFLZxkUus6MxWEPYPGbL3fb8Fs7Dk32HnNGgoBPiS7qFb3SvPLxWo_2QvZCXC04PIWlNSiyhLL9F15daOHMiKAFmQViqIBycGKM22k9e.ILbQH8v.zgBU2OA.nCiqTTvpp3L0g1MOqtryl_Em2yx7.Vxulq3Evbc_eqyZPv9GuHxSvf_F2IYIOTOYlDM2MSXjo9KGJLLuXARfkyZ9kHSkxsNsedMlpRiBC8.ujgWNMj9FCZJr8kPED_oQV1oVaa9V_xmJH1zpFFQJ_e_qZ0l2vhChz719Nf2t2fni5JkbTFST29jZ4bi_glu3Xkfsx3eRr7G.VPCxYukUBu64sLz6wn3Fn1ygRPsxeLNwB0H9Tc9Yxg_LLEyZ02plDqfBBb6ImdDOoFkhAlbVwo.kvUuKISMzRwZkH6I7ZfudM4PUHDrTmGBeqBwWzihWVousf8KOzKc7mASFaB7oeOmy6ona_gghOl5Sa24iLcnoWpnQ95thwXGZ1fAuqDakQK4ZNeYiE2gUeQRZRWBxZ2_Chb1fgiKuzUmXR0alTvStjqaDfKpeG44sAvFgEy0MxsJQg5ATeNO7OjMd3ps_rGSgv91zmzF5dEG3Kme2KrgoVWL1z4iDLxfCUgG_lZDfIroud7oE89UwpiGatRvXG3gy6R9RZWrcjoLmXLEukMsm90SYilaelMR1Kl4.hcNbTeP4V0Io1sr3Kzcy9TCkrWTwsc2hJcJknKXN_9_DGWxANUl2NdlsCEEknjMPFyq26dMpW9rN0s1MFGYwDgASbaqOgqAgZ_PZb6sYbSKuEku53y9f87sJDdS2JNfXzioo.DZ5P_8IitSulgJO4ZlAylTNNwQTUa.wvfSYHPS8NP4t0W7wqbwdFsnt41QdKD1piLn5axsXeTusLfrLVDJ8T1C87jcyMrCuBGdUhIqXhQU0K5LQcZk27GtYHpq5GVteY1DG4kxTn6xdem.waUgDwWXGOmOItI_oEWSf73kXeRCznnv90LsH_ECgQ8AZypJPI3ebYcbUA_hSamevBimxsGSzc0mhFwDr_4xtoHz70_nXO6MA86nQfsBdEz3osqMI1V7A5BSnBDOuo1WmCIOptLR3VZbDTX6zBy1yoz_ryciGhELFcIFkdQNu6DM.rBYxL2U.zQCP876Y8tya4ouvlIM0sSWQG2JltQDAv2pXwwACFWKkKEmqUguKGY2Bwmq8J0fOzn8QqDSCe61Ofcr_8xIMPMQZlP7BhEyxIkqC4mkyTosHXWBUIE9fTm2REsZVBSR3Gvoqy4KtCFDwtu33RYr.XFDTo4gYSEdoUfAoPNyRccBbwp9gNZh0H1mT2ZRW9MnfpJ6mtmnTuxs"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9135c20d6805fd95';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/abstracts\/search?q=phone%20number%20spoofing&__cf_chl_rt_tk=EJXdB_guOAPxMr5rHH9BTHTV1nZCe7fNFUyGpjiz9e4-1739795104-1.0.1.1-.fvkz.pXBlOAcq0yxVFH3.sQDxtU9916fdCZyl5Lmfk" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>