{"id":6786,"date":"2016-12-29T13:02:35","date_gmt":"2016-12-29T10:02:35","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=6786"},"modified":"2016-12-29T13:02:35","modified_gmt":"2016-12-29T10:02:35","slug":"cinin-uzaya-gonderdigi-ilk-kuantum-iletisim-uydusu-nasil-calisiyor","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2016\/12\/29\/cinin-uzaya-gonderdigi-ilk-kuantum-iletisim-uydusu-nasil-calisiyor","title":{"rendered":"\u00c7in\u2019in uzaya g\u00f6nderdi\u011fi ilk kuantum ileti\u015fim uydusu nas\u0131l \u00e7al\u0131\u015f\u0131yor?"},"content":{"rendered":"

Kuantum \u00f6zellikli ilk ileti\u015fim uydusu, tam ad\u0131yla Uzay \u00d6l\u00e7eklerinde Kuantum Deneyleri (QUESS) Uydusu, \u00c7in taraf\u0131ndan 16 A\u011fustos 2016\u2019da f\u0131rlat\u0131lm\u0131\u015ft\u0131.<\/p>\n

Boston \u00dcniversitesi\u2019nden elektrik ve bilgisayar m\u00fchendisi Prof. Alexander Sergienko, \u201cYap\u0131lacak deneyler ilk oldu\u011fu i\u00e7in d\u00fcnya \u00e7ap\u0131nda \u00f6neme sahip ve heyecan verici\u201d diyor. Sergienko, kuantum ileti\u015fim yar\u0131\u015f\u0131n\u0131n 20 y\u0131ldan beri s\u00fcrd\u00fc\u011f\u00fcn\u00fc belirtiyor. \u201cKuantum \u015eifreli Anahtar Da\u011f\u0131l\u0131m\u201d ba\u011flant\u0131s\u0131n\u0131n ilk denemesi 1995\u2019de Cenevre (Geneva) G\u00f6l\u00fc\u2019nde yap\u0131lm\u0131\u015ft\u0131.<\/p>\n

Sonraki d\u00f6nemde Boston, Viyana, Pekin ve Tokyo\u2019da geli\u015ftirildi ve g\u00f6sterime sunuldu. Son be\u015f y\u0131lda da Kanada, \u0130talya, \u0130ngiltere ve Avustralya\u2019da bir\u00e7ok kuantum metropolitan ileti\u015fim a\u011f\u0131 yap\u0131ld\u0131.<\/p>\n

600 kg a\u011f\u0131rl\u0131\u011f\u0131ndaki QUESS Uydusu\u2019nda, \u201cdola\u015f\u0131k fotonlar\u201d \u00fcreten bir kristal bulunuyor. Uydu, 500 km y\u00fckseklikteki y\u00f6r\u00fcngesinde, her 90 dakikada bir d\u00fcnya \u00e7evresini dolan\u0131yor.<\/p>\n

\u0130ki y\u0131ll\u0131k misyonu s\u0131ras\u0131nda QUESS, uzaydan yere \u015fifreler g\u00f6ndererek \u201ck\u0131r\u0131lmas\u0131 imk\u00e2ns\u0131z\u201d (hack-proof) kuantum ileti\u015fimini ger\u00e7ekle\u015ftirecek. B\u00f6ylece, kuantum fizi\u011finin en tuhaf olay\u0131 olan \u201ckuantum dola\u015f\u0131kl\u0131\u011f\u0131na\u201d ili\u015fkin de g\u00f6r\u00fc\u015f sunacak. Kuantum mekani\u011finin temel do\u011fas\u0131, g\u00f6zlemler ba\u011flam\u0131nda son derece duyarl\u0131 olmas\u0131 ve gizli bir bilginin kopyalanmas\u0131na izin vermemesidir. Bu nedenle kuantum ileti\u015fim a\u011flar\u0131n\u0131 k\u0131rmak olanaks\u0131zd\u0131r.<\/p>\n

\u201cKuantum \u015fifreli anahtar da\u011f\u0131l\u0131m\u0131\u201d (QKD – Quantum Key Distribution) ileti\u015fimin g\u00fcvenli\u011fini sa\u011flamak amac\u0131yla kuantum mekani\u011fini kullan\u0131r. QKD, ileti\u015fim halindeki iki ki\u015finin ve\/veya kurumun yaln\u0131zca kendilerinin bildi\u011fi, geli\u015fig\u00fczel se\u00e7ilmi\u015f ve ortak \u015fifreli anahtar \u00fcretmesini sa\u011flar. Bu durum \u00e7o\u011fu zaman \u201ckuantum kriptografisi\u201d olarak yanl\u0131\u015f adland\u0131r\u0131l\u0131r.<\/p>\n

\u201cKuantum \u015fifreli anahtar da\u011f\u0131l\u0131m\u201d sisteminin \u00f6nemli ve kendine \u00f6zg\u00fc \u00f6zelli\u011fi, birbiriyle ileti\u015fim halindeki iki ki\u015finin \u00f6zel bilgilerine s\u0131zmaya, \u015fifreyi k\u0131rmaya \u00e7al\u0131\u015fan \u00fc\u00e7\u00fcnc\u00fc ki\u015fiyi derhal alg\u0131lamas\u0131d\u0131r. \u015eifreyi bulmaya \u00e7al\u0131\u015fan \u00fc\u00e7\u00fcnc\u00fc ki\u015fi \u015fifrenin \u00f6l\u00e7\u00fcm\u00fcn\u00fc yapmak zorundad\u0131r; bu \u00e7abas\u0131 s\u0131ras\u0131nda ileti\u015fim halindeki iki ki\u015finin alg\u0131layabilece\u011fi anormalliklerin \u00fcretilmesine neden olur. E\u011fer \u00fc\u00e7\u00fcnc\u00fc ki\u015finin s\u0131z\u0131nt\u0131 d\u00fczeyi belli bir seviyenin alt\u0131ndaysa anahtar \u015fifre \u00fcretilir ve g\u00fcvenilirli\u011fi garantilenir (s\u0131zan ki\u015fi \u015fifre hakk\u0131nda bilgi sahibi olamaz), aksi takdirde g\u00fcvenilir \u015fifre olu\u015fturulamaz ve iki ki\u015fi aras\u0131ndaki ileti\u015fimin gizlili\u011fi k\u0131r\u0131l\u0131r.<\/p>\n

\u201cKuantum \u015fifreli anahtar da\u011f\u0131l\u0131m\u0131\u201d yaln\u0131zca bir \u015fifrenin \u00fcretilip da\u011f\u0131l\u0131m\u0131 i\u00e7in kullan\u0131l\u0131r, herhangi bir verinin iletilmesi i\u00e7in de\u011fil. Daha sonra bu \u015fifre herhangi bir \u015fifreleme algoritmas\u0131yla kullan\u0131larak bir mesaj\u0131 \u015fifreleme veya \u015fifresini k\u0131rmada kullan\u0131l\u0131r. QKD ile ili\u015fkili en yayg\u0131n algoritma, geli\u015fig\u00fczel se\u00e7ilmi\u015f gizli bir \u015fifre ile kullan\u0131ld\u0131\u011f\u0131nda g\u00fcvenilirli\u011fi hemen hemen kesin olan \u201cone-time pad\u201d algoritmas\u0131d\u0131r.<\/p>\n

 <\/p>\n

\"BB84<\/a><\/h5>\n
BB84 protokol diyagram\u0131: Alice\u2019in g\u00fcvenli olmayan kuantum kanal\u0131ndan g\u00f6nderdi\u011fi polarize olmu\u015f foton, Bob taraf\u0131ndan alg\u0131lan\u0131yor; ancak Eve, Alice ile Bob aras\u0131ndaki ileti\u015fime s\u0131zmaya \u00e7al\u0131\u015f\u0131r.<\/em><\/h5>\n
Polarized Light Source<\/strong> \u2013 Polarize olmu\u015f \u0131\u015f\u0131k kayna\u011f\u0131; Polarization Detector<\/strong> \u2013 Polarizasyon algac\u0131; Insecure quantum channel<\/strong> \u2013 G\u00fcvenliksiz kuantum kanal\u0131)<\/em><\/h5>\n

 <\/p>\n

\u0130lk Kuantum \u015eifre Anahtar Da\u011f\u0131l\u0131m Protokol\u00fc (QKD)1984\u2019de Charles Bennett ve Gilles Brassard taraf\u0131ndan \u00f6nerildi ve bir dizi kuantum a\u011f\u0131 (yay\u0131n istasyonlar\u0131 \u015febekesi) ara\u015ft\u0131rmas\u0131nda uyguland\u0131. Bu protokolde kuantum<\/strong> birimleri (qubits)<\/strong> bir ki\u015fiden di\u011fer ki\u015fiye g\u00fcvenli olmayan kuantum a\u011f\u0131nda g\u00f6nderildi. Kuantum mekani\u011fi ve benzerini olu\u015fturamama kuram\u0131na g\u00f6re (bu kurama g\u00f6re geli\u015fig\u00fczel ve bilinmeyen bir kuantum durumunun dengini \u00fcretmek imk\u00e2ns\u0131zd\u0131r) mesaj\u0131 dinlemeye \u00e7al\u0131\u015fan ki\u015fi (Eve) kuantum mesaj\u0131n\u0131 g\u00f6nderen (Alice) veya alan ki\u015fi (Bob) taraf\u0131ndan alg\u0131lanmadan \u015fifreyi elde edemez (Bkz. \u015eekil).<\/p>\n

Kuantum kriptografi firmas\u0131 ID Quantique\u2019de \u00e7al\u0131\u015fan Gregoir Ribordy, kuantum ileti\u015fiminin sabun k\u00f6p\u00fc\u011f\u00fc \u00fczerine yaz\u0131lm\u0131\u015f mesaja benzedi\u011fini, e\u011fer bu mesaj yay\u0131nlan\u0131rken onu okumak isteyen birisi \u00e7\u0131karsa, mesaj\u0131n sabun k\u00f6p\u00fc\u011f\u00fc gibi patlayaca\u011f\u0131n\u0131 s\u00f6yl\u00fcyor.<\/p>\n

T\u00fcrb\u00fclantl\u0131 hava ko\u015fullar\u0131n\u0131n ve fiber ba\u011flant\u0131lardaki bozulmalar\u0131n olmad\u0131\u011f\u0131 uzay, kuantum ileti\u015fimi i\u00e7in cazip bir ortam olu\u015fturur. Nature<\/em> dergisinde, \u201cQUESS\u2019in birbiriyle sarma\u015f dola\u015f olan foton \u00e7iftleri \u00fcretme yetene\u011fine sahip oldu\u011fu i\u00e7in kuantum dola\u015f\u0131kl\u0131\u011f\u0131 deneylerini ger\u00e7ekle\u015ftirece\u011fi; ancak misyonun ilk g\u00f6revinin Pekin ile Viyana aras\u0131nda kuantum \u015fifreli anahtar sa\u011flamak olaca\u011f\u0131\u201d belirtiliyor.<\/p>\n

Uzay arac\u0131 Avrupa\u2019da konu\u015flu istasyonun \u00fczerinden u\u00e7arken istasyonla kuantum ba\u011flant\u0131s\u0131 kuracak, uydu ile Avrupa\u2019da konu\u015flu istasyon aras\u0131nda bir \u015fifre \u00fcretilecek. Bir s\u00fcre sonra uydu \u00c7in\u2019de konu\u015flu istasyonun \u00fczerinden ge\u00e7ecek ve \u00c7in\u2019deki istasyonla ikinci kuantum ba\u011flant\u0131s\u0131n\u0131 kurup \u015fifreyi g\u00fcvenilir duruma getirecek. Her iki \u015fifre de uyduda bulunacak ve bu iki \u015fifre birle\u015ftirilerek tek \u015fifre olu\u015fturulabilecek. Daha sonra klasik bir ileti\u015fim kanal\u0131yla her iki istasyona da, iki \u015fifre kombinasyonuyla olu\u015fturulmu\u015f olan tek \u015fifre g\u00f6nderilecek. Bu i\u015flem kamuya a\u00e7\u0131k olarak yap\u0131labilir, \u00e7\u00fcnk\u00fc kombine \u015fifreden kimse bilgi s\u0131zd\u0131ramaz. Yer\u2019de konu\u015flu istasyonlardan birisi bir tek \u015fifreye sahip oldu\u011fu i\u00e7in kombine \u015fifreyi \u00e7\u00f6z\u00fcp di\u011fer istasyonun \u015fifresini \u00f6\u011frenebilir.<\/p>\n

E\u011fer iki y\u0131ll\u0131k olarak planlanan g\u00f6rev ba\u015far\u0131ya ula\u015f\u0131rsa, kuantum ileti\u015fim uydular\u0131 zincirinin ilk halkas\u0131 ve kuantum ileti\u015fiminin \u00f6nc\u00fcs\u00fc olacakt\u0131r.<\/p>\n

\u00a0<\/strong><\/p>\n

Haz\u0131rlayan: Prof. Rennan Pek\u00fcnl\u00fc<\/strong><\/p>\n

\u00a0<\/strong><\/p>\n

Kaynaklar:<\/strong><\/p>\n

– Nature<\/em>, 535, pp. 478-479, 28 July 2016<\/p>\n

– https:\/\/en.wikipedia.org\/wiki\/Quantum_network<\/a><\/p>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

Kuantum \u00f6zellikli ilk ileti\u015fim uydusu, tam ad\u0131yla Uzay \u00d6l\u00e7eklerinde Kuantum Deneyleri (QUESS) Uydusu, \u00c7in taraf\u0131ndan 16 A\u011fustos 2016\u2019da f\u0131rlat\u0131lm\u0131\u015ft\u0131. Boston \u00dcniversitesi\u2019nden elektrik ve bilgisayar m\u00fchendisi Prof. Alexander Sergienko, \u201cYap\u0131lacak deneyler ilk oldu\u011fu i\u00e7in d\u00fcnya \u00e7ap\u0131nda \u00f6neme sahip ve heyecan verici\u201d diyor. Sergienko, kuantum ileti\u015fim yar\u0131\u015f\u0131n\u0131n 20 y\u0131ldan beri s\u00fcrd\u00fc\u011f\u00fcn\u00fc belirtiyor. \u201cKuantum \u015eifreli Anahtar Da\u011f\u0131l\u0131m\u201d ba\u011flant\u0131s\u0131n\u0131n […]<\/p>\n","protected":false},"author":1,"featured_media":6787,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19,26],"tags":[],"class_list":["post-6786","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","category-fizik"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t

– http:\/\/english.cas.cn\/newsroom\/news\/201608\/t20160816_166485.shtml<\/a><\/p>\n