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: '91363ebf480a3dad',cH: 'KIv6yMF21sZDkFKFP5TA1j.A457i5qRtaWJGcyw12ok-1739800212-1.2.1.1-tYrIxQ2q8Q6JgkkY0qwZlOVbX.Ol8vOiikXvS7JozJM6E4hhV9oWfyGOXCLEVsUG',cUPMDTk: "\/search?q=secure%20communication&__cf_chl_tk=3mldCN8tbZS7Mq2tt6JlHbGN19t3o79TZG2qwAE3px0-1739800212-1.0.1.1-IK3giWRr.3zq72bja6r8lib_Mt6R9EZcRco2vOJg92s",cFPWv: 'b',cITimeS: '1739800212',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/search?q=secure%20communication&__cf_chl_f_tk=3mldCN8tbZS7Mq2tt6JlHbGN19t3o79TZG2qwAE3px0-1739800212-1.0.1.1-IK3giWRr.3zq72bja6r8lib_Mt6R9EZcRco2vOJg92s",md: "bRbigTbAuD5q.N7X5WbjnWXFMl0uTU8liLGMwzEd_E4-1739800212-1.2.1.1-lxVCEp9Dcu2DTZPt9AnVjJv0Zkdy6j0jKLrdMq6eLNRJwluhdOkpg7N8ecfNxmMnBp9a7PZH5NZkaFwjXcmTOUwfK7ccrD2oimX0yFe7nfNEFJ_TKL1kiinV9IzQkk7cjABEXu2E_6hyWRL3u3tH_VcfBGTxNoo3nZ_F3iV0q.zQfLqZWY.8vxQVHGALXxlBkPZepsWuvWOUHY0mZ8El77PL7t0ber8Jt6lcnY50eEiceardCN9XudRsQtv1qQMR9r1CIHKbSkqvZnkf4WzzpWfDWqPZ_ruHwG5ckkfRoeaJ4HCbgfPeWMOWCofJbtSSxWkqfxvxZUOLvJ5eQ7ECbrUI4_p1mpvlDGl0ID_sVdBSb5wF2BF2lnJhQ3gTEAQcwoQbTXJM2qHGJGMUAgq3bPxvD0kRA_NJplUfMNTjJsQRY.Wqj_jkO3UlrCdJ83dwlp2WlzE07UFdO9Hz9PWCwxUhbaIEF3LkgV9MLogAJm0ZmX3zfV_aOa06CUkB7K_Zb2EczpNaBqfmF42dX7UpYl9HY8jH4y3m5gQRzvqgmWidN7..yyw6ghszmujiAXJ31T0n4pQpTFRW1q.aAM2jeRjRvqdhtDSamsBD5wrGNT58z_XrbK7C6GhoPYBc9wyi9BE82KxDT4A57VXH.fYdE8muizR3Sp7IRLWghn.EIbjngwYqUhVpmZ7b_fDAoZoPJ8zWrdBFLv6DI1JlidvDhtDpa.C0RfEaYi95bDoTdLuV.gb.sRS0ctsELhm_vASQ.3HdmLi3GmfbSl3DVonnOiEJFxtGVayPLRrUS2f7iKW2aRRY1czsW7BetNI467joBDqPbC0Lc6Wi2IP5ZB3NDXOqXzQv0TW41g1eeMlfjhiE9W9Nh3tpAep7fEqD_k3VPlDSFlC8c_0kzqsSAVCOdESe8dy_vvthHfm.rt5dloSw3Aiw.hboaQkGL4npZFZrY4Nzq3CTpfhRnUrJ7PxR5FJX063GfiBevzQEcB96xyyo2naCgAQL6BgS4_eafNT6ssxv.YjtUK.lU5UZAjWFIEvxMTCSbjnrNyvfRBC8NrvsllUdZyYyuHFFcivL16NWaJ.dXQ.zL4_TLldus2MG5UwKoHcV4FYTd71cOhjU9AXGWRZD01soOzLOFBFtRPNR9okGA_IxaJEhFNGy7jJp9Z5IuVeHLqwoMbcyx52IqsQSPfjYTtmpEnW5lBi8isIC1NgZgeX.EPAe7cL1CLTy4jkroUPGH51fBJn9iwxxAAI66HE_GyIXQCCoO.eElvIRhQcd17ffUE2sxoQLk17nIOEEZIn8XZyIb9VxHdMq2pjbZd5.xN_Ls_1w0rKFFJvRpymDKduNA.Hzxti61R93nL6m00i3_hbXFLeJxHIW0CMdCtNuczYXXNS5Op4iTRX_0CJ258a6z8AJV4WM7F1x3sPlXFiQ3Az9zNzVMrf8bEsebf5NKxg4fHph.8Mii.m39wt3RZ1nHkkJJsYXTbGpnZh4pW92VI9P0Xsxs1f6PioCc2ci8CTwTrSq7wMvncy3NuXPSuHnYEp9hfNcC49qPaPvBtP35IRkYYiqH37WJ9ByHUywDFUsVKL9kzId4KddZUV_FhAjBL5wAYBk57ySK4Dd2fzH7_U2BWhNRN8do3HRnBWjiehVo3XtqKaKkthKY0s2RmPy.rH0Z5DX8FvpwBqU70lCa_hEELbvxemcNT6bpm7_CEWZygE6uTpafXDJMuOh8fokaUyTNLf_f.2blbXemhaCx6BHI80XXQWV9zsbdoFOFbUom6yno_3B61R3OCGDAfZYtysVbzErLxCTQBL__1HqKW_keoVeaxtIidCCrD3g.6M45EXr4vv0ZOxj_Vzga7zAcn2l54CFKWVgAsCbrPSeG3OssrvizK2I9BAjdCfs_HAhElL_63W_wd76K8gHTyGM59X4Cw8RvgBwLQ",mdrd: "oyPVOczSiLL09rKLK41wEboTX_YAqZROeumFqUqZdFg-1739800212-1.2.1.1-7zKlXJ2n.wxeHc9fVVpu3KBarsPl9M_uwwGuIeSpXXlIhC1pt17wyvtoc6SsqnnDGAmYLGiAaruOSotx0VGRAqY35jFuLwuSQG1ZEC8UxIIaRGOKViIai8qaAf4vK1eGcwR49Q.iXhjB7aTKzJharV5kvvUyd7g8ptXO5vmeOaSktPF180eOOyAu9xjoFdWi9p2sMV6aw2QpyInIUCluFR2j3UfwsNDCHtHZgo0sd0QoHVtSfZuTRvtHEkClupyR2K4dEt6sDRzziWy6JPJaK020dzG_8aZiBSh8JrVymHvQEPbTi.OMRA815vctP1CzQmiek5LO2cm4gAIYab75PDcJevFGJGENQkhrgOgnQM.jtfNftqyq_5Us31jTgGCY73iJw6XFKT.sP8iDKfUxdr16czvtvmB6_BXd9Zkuu9AZ_9UOf6QOpYMaHY7Hx6rxn7LiukiIO0pBP7H997WXUSayzGk330kz2oy46giScMZctyO5FP..M.6oO.KNp_z7.9iJQp.2ovwA4fsDkqccAQfHzmSeFHENJz.icIxSDxON_NOf6QZqm3T8w0ozFAsxKhG7jDeDF1yWBULEPLB0qrZ0cd_kvGK3Z9ziS0yAer2pjx2Eua5omEj2wO65nSFS52rM.32UZsFeuD2jXqpnl0WqLnp4bYrItiFgaHoTVVO_6fa8B7lMjXTZI0vNuzPK_YuenU4Le2gNTi9N0pzTruc8uWqGgIpATOfDjI7pg9ryFa9QniODH9HCQJpVw3192TSv8vEuzCpaq8yb3Flko3oskv.NHhf95EZU3bLkH2U63g8Z6H4eSJdZFbAIeoRSO3icYdVglVKYFxHhkAl6kLBvIKfIw16oFTdrIPmKnBl5C9kTwdCCYFoPWa95r2O24FoxdZduhG6hk66bsKd7bxacVjo6G6RuLDjnZ6e3jQZC011rJGpZYUyyZ9DWb8KOCPBfqPUZohzj622fn_r94foUTIzNIm.l8STGblsoH9IRlqQlbzKkNaavRprliV0OhH9ghCQVt1DEE4O06tFNt1Zm_rlKEBBfOKHnQl6n6hJbkt6MYEBQpfnCPSaxSqGcDtAfBCHxI0oUeuJE_CwI0HqmfXqZjjIEF3RX3bta7kY8f_ouZUx18IV.Axxcnby4cztsqx4.RVaHbS72MHZFLRWFa1AyDhmnz2fOZx4HJUySE3DvEZRddy4iavqXrU9jTP6nH_Agy316kp_DPrqYkzXxYdHOVi_S_g7ZefbNObvqHUmVJom9MLqyPVd7cDFdl7tQkn_6Z1hvjVY2olywZVXFr3Th_6iwMokaadoCLzRnXbX2c7fp6OBxnbMgzyiZ_P6vjAxZzkmOu9T3CeX.ht.4gfthAg8_SEzNL8T5WpCBrQYsq8IghYl8N34h8bpCHHeYt320AoPIrz9M_03lIOmcnD5MvBOW9GccNsxt7m0u_ZNMXnnEbo4LZm1azTFJPloZHzKBTBy..YBMtmiAQNetZ87k4U_0Z_CM7UBuNptPO_gPJLP9ejQjpY6l9SUL_F08688XkH0l2Ig5gRrAWDLerY3EeDbpess2AB0KAGrNQXx_iZcDGu4Ns1OPAdUGJz1Y6ix3pYUQltkw6.g_X5psy1PXAZOXnCoZOmi_x78NuJXWyuvQB16tKqE9eJll1xNMfNFhMizqnKIC0KdQyWmU8ZJhahOt8JwhIM9WsFmSvP_lwuNsJ4P.RyoPUeED4ZwSEXy9cPE.SWp9lyM8dDeAzQmHlWFDD_smfupxpqt0ttzwrHb.jqEcH6zpObwmiuiNG3ytSWcFXqWvbxsBtc.pXoxVQPBiCu3k44Hcn8gwqEbkfHUq8JTlInGPlU5yh1pBRWlXJdGdXZL6oIBwxBnOy4J8QU_Dg2Vdy6gaYayzYqiPPFiGqGSPJ.rJ.ocpBqzvv2vG6mgLmL3pwqUiWjSFpmuded8NHjA_J2DtmQtkCy0D.K_vxYUmVDR3IdkH"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=91363ebf480a3dad';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, "\/search?q=secure%20communication&__cf_chl_rt_tk=3mldCN8tbZS7Mq2tt6JlHbGN19t3o79TZG2qwAE3px0-1739800212-1.0.1.1-IK3giWRr.3zq72bja6r8lib_Mt6R9EZcRco2vOJg92s" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>