{"id":15809,"date":"2026-06-04T17:21:01","date_gmt":"2026-06-04T14:21:01","guid":{"rendered":"https:\/\/www.ihs.com.tr\/blog\/?p=15809"},"modified":"2026-06-04T17:21:01","modified_gmt":"2026-06-04T14:21:01","slug":"sha-1-sha-256-ve-sha-3-nedir","status":"publish","type":"post","link":"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/","title":{"rendered":"SHA-1, SHA-256 ve SHA-3 Nedir? SSL Sertifikalar\u0131ndaki \u015eifreleme (Hash) Algoritmalar\u0131n\u0131n Farklar\u0131"},"content":{"rendered":"<p>\u0130nternet \u00fczerinde gezinirken, bir e-ticaret sitesinden al\u0131\u015fveri\u015f yaparken veya bankac\u0131l\u0131k i\u015flemlerinizi ger\u00e7ekle\u015ftirirken verilerinizin g\u00fcvenli\u011fi nas\u0131l sa\u011flan\u0131r? Bu g\u00fcvenli\u011fin temel ta\u015flar\u0131ndan biri, karma\u015f\u0131k matematiksel problemlerle verileri benzersiz bir parmak izine d\u00f6n\u00fc\u015ft\u00fcren kriptografik \u00f6zet, yani &#8220;hash&#8221; fonksiyonlar\u0131d\u0131r. \u00d6zellikle web sitelerinin kimli\u011fini do\u011frulayan ve veri ak\u0131\u015f\u0131n\u0131 \u015fifreleyen SSL sertifikalar\u0131, bu algoritmalar\u0131n g\u00fcc\u00fcne dayan\u0131r. Ge\u00e7mi\u015fte end\u00fcstri standard\u0131 olan ancak art\u0131k g\u00fcvenli\u011fini yitiren SHA-1&#8217;den, g\u00fcn\u00fcm\u00fcz\u00fcn alt\u0131n standard\u0131 SHA-256&#8217;ya ve gelece\u011fin g\u00fcvenlik mimarisi olarak g\u00f6r\u00fclen SHA-3&#8217;e kadar bu algoritmalar\u0131n evrimi, dijital g\u00fcvenli\u011fin de evrimini temsil eder. Bu makalede, SHA-1, SHA-256 ve SHA-3 aras\u0131ndaki temel farklar\u0131, SSL\/TLS sertifikalar\u0131ndaki rollerini ve dijital g\u00fcvenli\u011finiz i\u00e7in neden do\u011fru algoritmay\u0131 se\u00e7menin hayati oldu\u011funu derinlemesine inceleyece\u011fiz.<\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_77 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">\u0130\u00e7erik Tablosu<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-6a21c6a56b4d6\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\" id=\"ez-toc-cssicon-toggle-item-6a21c6a56b4d6\" aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Kriptografik-Ozet-Hash-Fonksiyonlarinin-Temelleri\" >Kriptografik \u00d6zet (Hash) Fonksiyonlar\u0131n\u0131n Temelleri<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Kriptografik-Hash-Fonksiyonu-Nedir\" >Kriptografik Hash Fonksiyonu Nedir?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Hash-Algoritmalarinin-Temel-Ozellikleri\" >Hash Algoritmalar\u0131n\u0131n Temel \u00d6zellikleri<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Veri-Butunlugu-ve-Kimlik-Dogrulamadaki-Rolu\" >Veri B\u00fct\u00fcnl\u00fc\u011f\u00fc ve Kimlik Do\u011frulamadaki Rol\u00fc<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SHA-1-Algoritmasi-Guvenligi-Kirilan-Eski-Standart\" >SHA-1 Algoritmas\u0131: G\u00fcvenli\u011fi K\u0131r\u0131lan Eski Standart<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SHA-1-Nedir\" >SHA-1 Nedir?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Teknik-Ozellikleri-ve-Calisma-Prensibi-160-bit-Cikti\" >Teknik \u00d6zellikleri ve \u00c7al\u0131\u015fma Prensibi (160-bit \u00c7\u0131kt\u0131)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Guvenlik-Zafiyetleri-Cakisma-Collision-Saldirilari\" >G\u00fcvenlik Zafiyetleri: \u00c7ak\u0131\u015fma (Collision) Sald\u0131r\u0131lar\u0131<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Tarayicilar-ve-Sertifika-Otoriteleri-Tarafindan-Neden-Terk-Edildi\" >Taray\u0131c\u0131lar ve Sertifika Otoriteleri Taraf\u0131ndan Neden Terk Edildi?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SHA-256-Algoritmasi-Gunumuzun-Endustri-Standardi\" >SHA-256 Algoritmas\u0131: G\u00fcn\u00fcm\u00fcz\u00fcn End\u00fcstri Standard\u0131<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SHA-2-Ailesi-ve-SHA-256-Nedir\" >SHA-2 Ailesi ve SHA-256 Nedir?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Teknik-Yapisi-ve-Guvenlik-Mekanizmalari-256-bit-Cikti\" >Teknik Yap\u0131s\u0131 ve G\u00fcvenlik Mekanizmalar\u0131 (256-bit \u00c7\u0131kt\u0131)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SHA-1e-Gore-Ustunlukleri-ve-Guvenlik-Farklari\" >SHA-1&#8217;e G\u00f6re \u00dcst\u00fcnl\u00fckleri ve G\u00fcvenlik Farklar\u0131<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SSLTLS-Sertifikalarinda-ve-Modern-Uygulamalardaki-Yeri\" >SSL\/TLS Sertifikalar\u0131nda ve Modern Uygulamalardaki Yeri<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SHA-3-Algoritmasi-Gelecegin-Guvenlik-Mimarisi\" >SHA-3 Algoritmas\u0131: Gelece\u011fin G\u00fcvenlik Mimarisi<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SHA-3-Nedir-ve-Gelistirilme-Amaci\" >SHA-3 Nedir ve Geli\u015ftirilme Amac\u0131<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Temelindeki-%E2%80%9CKeccak%E2%80%9D-Algoritmasi-ve-Yapisal-Farkliliklari\" >Temelindeki &#8220;Keccak&#8221; Algoritmas\u0131 ve Yap\u0131sal Farkl\u0131l\u0131klar\u0131<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SHA-2den-Farkli-Tasarimi-ve-Potansiyel-Avantajlari\" >SHA-2&#8217;den Farkl\u0131 Tasar\u0131m\u0131 ve Potansiyel Avantajlar\u0131<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Gunumuzdeki-Adaptasyon-Sureci-ve-Gelecekteki-Rolu\" >G\u00fcn\u00fcm\u00fczdeki Adaptasyon S\u00fcreci ve Gelecekteki Rol\u00fc<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Hash-Algoritmalarinin-Karsilastirmali-Analizi\" >Hash Algoritmalar\u0131n\u0131n Kar\u015f\u0131la\u015ft\u0131rmal\u0131 Analizi<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Guvenlik-Seviyeleri-ve-Saldirilara-Karsi-Direnc\" >G\u00fcvenlik Seviyeleri ve Sald\u0131r\u0131lara Kar\u015f\u0131 Diren\u00e7<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Cikti-Ozet-Uzunluklari-160-bit-vs-256-bit-vs-Degisken-Uzunluk\" >\u00c7\u0131kt\u0131 (\u00d6zet) Uzunluklar\u0131: 160-bit vs 256-bit vs De\u011fi\u015fken Uzunluk<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Performans-ve-Hiz-Farkliliklari\" >Performans ve H\u0131z Farkl\u0131l\u0131klar\u0131<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Algoritmik-Yapi-ve-Tasarim-Felsefeleri\" >Algoritmik Yap\u0131 ve Tasar\u0131m Felsefeleri<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#SSLTLS-Sertifikalarinda-Hash-Algoritmalarinin-Kritik-Rolu\" >SSL\/TLS Sertifikalar\u0131nda Hash Algoritmalar\u0131n\u0131n Kritik Rol\u00fc<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Dijital-Imza-Nedir-ve-Hash-Algoritmasi-Nasil-Kullanilir\" >Dijital \u0130mza Nedir ve Hash Algoritmas\u0131 Nas\u0131l Kullan\u0131l\u0131r?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Sertifika-Otoritesi-CA-Imzalama-Sureci\" >Sertifika Otoritesi (CA) \u0130mzalama S\u00fcreci<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Guven-Zincirinde-Chain-of-Trust-Veri-Butunlugunun-Saglanmasi\" >G\u00fcven Zincirinde (Chain of Trust) Veri B\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fcn Sa\u011flanmas\u0131<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Bir-Web-Sitesinin-Kullandigi-Imza-Algoritmasi-Nasil-Kontrol-Edilir\" >Bir Web Sitesinin Kulland\u0131\u011f\u0131 \u0130mza Algoritmas\u0131 Nas\u0131l Kontrol Edilir?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Dogru-Hash-Algoritmasini-Secmenin-Onemi\" >Do\u011fru Hash Algoritmas\u0131n\u0131 Se\u00e7menin \u00d6nemi<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Neden-SHA-256-veya-Uzeri-Algoritmalar-Tercih-Edilmeli\" >Neden SHA-256 veya \u00dczeri Algoritmalar Tercih Edilmeli?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-32\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Eski-Algoritmalari-Kullanmanin-Riskleri\" >Eski Algoritmalar\u0131 Kullanman\u0131n Riskleri<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-33\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Gelecege-Donuk-Kriptografik-Ceviklik-Crypto-Agility\" >Gelece\u011fe D\u00f6n\u00fck Kriptografik \u00c7eviklik (Crypto-Agility)<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-34\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Guvenli-SSL-Sertifikalari-Icin-Neden-IHS-Telekomu-Tercih-Etmelisiniz\" >G\u00fcvenli SSL Sertifikalar\u0131 \u0130\u00e7in Neden \u0130HS Telekom&#8217;u Tercih Etmelisiniz?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-35\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#En-Guncel-SHA-2-ve-Ustu-Algoritmalari-Destekleyen-Sertifikalar\" >En G\u00fcncel SHA-2 ve \u00dcst\u00fc Algoritmalar\u0131 Destekleyen Sertifikalar<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-36\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Farkli-Ihtiyaclara-Yonelik-Genis-Sertifika-Portfoyu\" >Farkl\u0131 \u0130htiya\u00e7lara Y\u00f6nelik Geni\u015f Sertifika Portf\u00f6y\u00fc<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-37\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Kolay-Kurulum-ve-Uzman-Teknik-Destek-Hizmeti\" >Kolay Kurulum ve Uzman Teknik Destek Hizmeti<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-38\" href=\"https:\/\/www.ihs.com.tr\/blog\/sha-1-sha-256-ve-sha-3-nedir\/#Guclu-Sifreleme-ile-Web-Sitenizin-ve-Kullanicilarinizin-Guvenligini-Saglama\" >G\u00fc\u00e7l\u00fc \u015eifreleme ile Web Sitenizin ve Kullan\u0131c\u0131lar\u0131n\u0131z\u0131n G\u00fcvenli\u011fini Sa\u011flama<\/a><\/li><\/ul><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Kriptografik-Ozet-Hash-Fonksiyonlarinin-Temelleri\"><\/span>Kriptografik \u00d6zet (Hash) Fonksiyonlar\u0131n\u0131n Temelleri<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Kriptografik hash fonksiyonlar\u0131, dijital d\u00fcnyan\u0131n temel g\u00fcvenlik yap\u0131 ta\u015flar\u0131ndan biridir. Herhangi bir boyuttaki bir veriyi (metin, dosya, resim vb.) al\u0131p, onu sabit uzunlukta, benzersiz ve geri d\u00f6nd\u00fcr\u00fclemez bir karakter dizisine, yani bir &#8220;\u00f6zet&#8221; veya &#8220;hash&#8221; de\u011ferine d\u00f6n\u00fc\u015ft\u00fcren matematiksel algoritmalard\u0131r. Bu s\u00fcre\u00e7, bir verinin dijital parmak izini olu\u015fturmaya benzer.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Kriptografik-Hash-Fonksiyonu-Nedir\"><\/span>Kriptografik Hash Fonksiyonu Nedir?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Bir kriptografik hash fonksiyonu, temel olarak tek y\u00f6nl\u00fc bir i\u015flemdir. Girdi olarak ne kadar b\u00fcy\u00fck veya k\u00fc\u00e7\u00fck bir veri verilirse verilsin, \u00e7\u0131kt\u0131 her zaman ayn\u0131 uzunluktad\u0131r. \u00d6rne\u011fin, SHA-256 algoritmas\u0131 i\u00e7in bu \u00e7\u0131kt\u0131 her zaman 256-bit (64 karakter) uzunlu\u011fundad\u0131r. Bu fonksiyonun amac\u0131, verinin b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc ve orijinalli\u011fini do\u011frulamakt\u0131r. E\u011fer veride en ufak bir de\u011fi\u015fiklik bile olursa, ortaya \u00e7\u0131kacak olan hash de\u011feri tamamen farkl\u0131 olur. Bu \u00f6zellik, onu veri b\u00fct\u00fcnl\u00fc\u011f\u00fc kontrolleri ve parola saklama gibi alanlarda vazge\u00e7ilmez k\u0131lar.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Hash-Algoritmalarinin-Temel-Ozellikleri\"><\/span>Hash Algoritmalar\u0131n\u0131n Temel \u00d6zellikleri<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Bir hash fonksiyonunun kriptografik olarak g\u00fcvenli kabul edilebilmesi i\u00e7in belirli temel \u00f6zelliklere sahip olmas\u0131 gerekir. Bu \u00f6zellikler, algoritman\u0131n sald\u0131r\u0131lara kar\u015f\u0131 direncini ve g\u00fcvenilirli\u011fini belirler.<\/p>\n<h4>Tek Y\u00f6nl\u00fcl\u00fck (Geri D\u00f6nd\u00fcr\u00fclemezlik)<\/h4>\n<p>Bu, en temel \u00f6zelliktir. Bir hash de\u011ferinden yola \u00e7\u0131karak orijinal verinin ne oldu\u011funu hesaplamak matematiksel olarak imkans\u0131z veya pratik olarak olanaks\u0131z olmal\u0131d\u0131r. Bu nedenle hash fonksiyonlar\u0131, \u015fifreleme (encryption) ile kar\u0131\u015ft\u0131r\u0131lmamal\u0131d\u0131r. \u015eifrelemede veri do\u011fru anahtarla eski haline d\u00f6nd\u00fcr\u00fclebilirken, hash i\u015fleminde bu m\u00fcmk\u00fcn de\u011fildir. Bu \u00f6zellik, parolalar\u0131n veritabanlar\u0131nda do\u011frudan saklanmas\u0131 yerine hash&#8217;lenerek saklanmas\u0131n\u0131n temel nedenidir.<\/p>\n<h4>Deterministik Olma (Ayn\u0131 Girdi, Ayn\u0131 \u00c7\u0131kt\u0131)<\/h4>\n<p>Ayn\u0131 girdi, ne kadar tekrarlan\u0131rsa tekrarlans\u0131n her zaman birebir ayn\u0131 hash \u00e7\u0131kt\u0131s\u0131n\u0131 \u00fcretmelidir. &#8220;Merhaba D\u00fcnya&#8221; metni i\u00e7in SHA-256 algoritmas\u0131 her \u00e7al\u0131\u015ft\u0131r\u0131ld\u0131\u011f\u0131nda ayn\u0131 sonucu verir. Bu tutarl\u0131l\u0131k, veri do\u011frulama s\u00fcre\u00e7lerinin temelini olu\u015fturur. Bir dosyan\u0131n indirme sonras\u0131 bozulup bozulmad\u0131\u011f\u0131n\u0131 kontrol etmek i\u00e7in, orijinal dosyan\u0131n hash de\u011feri ile indirilen dosyan\u0131n hash de\u011feri kar\u015f\u0131la\u015ft\u0131r\u0131l\u0131r. E\u011fer de\u011ferler ayn\u0131ysa, dosya bozulmam\u0131\u015ft\u0131r.<\/p>\n<h4>\u00c7\u0131\u011f Etkisi (K\u00fc\u00e7\u00fck De\u011fi\u015fikli\u011fin B\u00fcy\u00fck Sonu\u00e7lar\u0131)<\/h4>\n<p>Girdide yap\u0131lan en k\u00fc\u00e7\u00fck bir de\u011fi\u015fiklik (bir harfin silinmesi, bir noktan\u0131n eklenmesi gibi) \u00e7\u0131kt\u0131da tamamen farkl\u0131 ve tan\u0131nmaz bir hash de\u011feri olu\u015fturmal\u0131d\u0131r. \u00d6rne\u011fin, &#8220;Mesaj&#8221; ile &#8220;mesaj&#8221; kelimelerinin hash de\u011ferleri aras\u0131nda hi\u00e7bir benzerlik olmamal\u0131d\u0131r. Bu \u00f6zellik, verinin de\u011fi\u015ftirilip de\u011fi\u015ftirilmedi\u011fini anlamay\u0131 son derece kolayla\u015ft\u0131r\u0131r.<\/p>\n<h4>\u00c7ak\u0131\u015fma Direnci (Collision Resistance)<\/h4>\n<p>Farkl\u0131 iki girdinin ayn\u0131 hash \u00e7\u0131kt\u0131s\u0131n\u0131 \u00fcretmesi durumu &#8220;\u00e7ak\u0131\u015fma&#8221; (collision) olarak adland\u0131r\u0131l\u0131r. G\u00fc\u00e7l\u00fc bir hash fonksiyonunda, kas\u0131tl\u0131 olarak bir \u00e7ak\u0131\u015fma bulmak hesaplama a\u00e7\u0131s\u0131ndan imkans\u0131za yak\u0131n olmal\u0131d\u0131r. Bir sald\u0131rgan, orijinal bir belgenin hash de\u011feriyle ayn\u0131 hash de\u011ferine sahip sahte bir belge olu\u015fturabilirse, bu durum g\u00fcvenlik sistemlerini tamamen atlatmas\u0131na olanak tan\u0131r. SHA-1 algoritmas\u0131n\u0131n terk edilmesinin temel nedeni, \u00e7ak\u0131\u015fma direncinin k\u0131r\u0131lm\u0131\u015f olmas\u0131d\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Veri-Butunlugu-ve-Kimlik-Dogrulamadaki-Rolu\"><\/span>Veri B\u00fct\u00fcnl\u00fc\u011f\u00fc ve Kimlik Do\u011frulamadaki Rol\u00fc<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Hash fonksiyonlar\u0131, veri b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc sa\u011flaman\u0131n en etkili yoludur. Bir yaz\u0131l\u0131m indirdi\u011finizde, sa\u011flay\u0131c\u0131n\u0131n web sitesinde genellikle dosyan\u0131n SHA-256 \u00f6zeti de yay\u0131nlan\u0131r. \u0130ndirme i\u015flemi tamamland\u0131ktan sonra, kendi bilgisayar\u0131n\u0131zda dosyan\u0131n hash&#8217;ini hesaplayarak orijinaliyle kar\u015f\u0131la\u015ft\u0131rabilir ve dosyan\u0131n transfer s\u0131ras\u0131nda bozulmad\u0131\u011f\u0131ndan veya k\u00f6t\u00fc niyetli ki\u015filerce de\u011fi\u015ftirilmedi\u011finden emin olabilirsiniz. Kimlik do\u011frulamada ise <a href=\"https:\/\/www.ihs.com.tr\/ssl\/\" target=\"_blank\">SSL sertifikas\u0131<\/a> gibi dijital imzalar kullan\u0131l\u0131rken, belgenin kendisi yerine hash&#8217;i imzalan\u0131r. Bu, hem i\u015flemi h\u0131zland\u0131r\u0131r hem de belgenin imzaland\u0131ktan sonra de\u011fi\u015ftirilmedi\u011fini garanti eder.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"SHA-1-Algoritmasi-Guvenligi-Kirilan-Eski-Standart\"><\/span>SHA-1 Algoritmas\u0131: G\u00fcvenli\u011fi K\u0131r\u0131lan Eski Standart<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Bir zamanlar dijital g\u00fcvenli\u011fin temel direklerinden biri olan SHA-1 (Secure Hash Algorithm 1), art\u0131k &#8220;g\u00fcvenli\u011fi k\u0131r\u0131lm\u0131\u015f&#8221; ve kullan\u0131m\u0131 kesinlikle \u00f6nerilmeyen bir algoritma olarak kabul edilmektedir. Geli\u015fen teknoloji ve hesaplama g\u00fcc\u00fc, SHA-1&#8217;in zay\u0131fl\u0131klar\u0131n\u0131 ortaya \u00e7\u0131karm\u0131\u015f ve onu siber sald\u0131r\u0131lara kar\u015f\u0131 savunmas\u0131z b\u0131rakm\u0131\u015ft\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"SHA-1-Nedir\"><\/span>SHA-1 Nedir?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-1, ABD Ulusal G\u00fcvenlik Ajans\u0131 (NSA) taraf\u0131ndan tasarlanan ve 1995 y\u0131l\u0131nda bir standart olarak yay\u0131nlanan bir kriptografik hash fonksiyonudur. Herhangi bir uzunluktaki girdiyi alarak 160-bit (40 onalt\u0131l\u0131k karakter) uzunlu\u011funda sabit bir \u00f6zet de\u011feri \u00fcretir. Uzun y\u0131llar boyunca dijital sertifikalar, yaz\u0131l\u0131m b\u00fct\u00fcnl\u00fc\u011f\u00fc kontrolleri ve \u00e7e\u015fitli g\u00fcvenlik protokollerinde yayg\u0131n olarak kullan\u0131lm\u0131\u015ft\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Teknik-Ozellikleri-ve-Calisma-Prensibi-160-bit-Cikti\"><\/span>Teknik \u00d6zellikleri ve \u00c7al\u0131\u015fma Prensibi (160-bit \u00c7\u0131kt\u0131)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-1, girdiyi 512-bit&#8217;lik bloklara b\u00f6lerek i\u015fler ve karma\u015f\u0131k matematiksel ad\u0131mlardan ge\u00e7irir. Bu ad\u0131mlar, kar\u0131\u015ft\u0131rma (scrambling), bit d\u00fczeyinde d\u00f6nd\u00fcrme (rotation) ve mant\u0131ksal fonksiyonlar\u0131 i\u00e7erir. \u0130\u015flemin sonunda, t\u00fcm bloklar\u0131n i\u015flenmesiyle elde edilen 160-bit&#8217;lik nihai bir \u00f6zet de\u011feri ortaya \u00e7\u0131kar. Bu 160-bit&#8217;lik \u00e7\u0131kt\u0131 uzunlu\u011fu, o d\u00f6nemin standartlar\u0131 i\u00e7in yeterli g\u00f6r\u00fclse de, g\u00fcn\u00fcm\u00fcz\u00fcn i\u015flem g\u00fcc\u00fc kar\u015f\u0131s\u0131nda yetersiz kalm\u0131\u015ft\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Guvenlik-Zafiyetleri-Cakisma-Collision-Saldirilari\"><\/span>G\u00fcvenlik Zafiyetleri: \u00c7ak\u0131\u015fma (Collision) Sald\u0131r\u0131lar\u0131<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-1&#8217;in en b\u00fcy\u00fck ve \u00f6l\u00fcmc\u00fcl zafiyeti, \u00e7ak\u0131\u015fma sald\u0131r\u0131lar\u0131na kar\u015f\u0131 savunmas\u0131z olmas\u0131d\u0131r. 2017 y\u0131l\u0131nda Google ve CWI Enstit\u00fcs\u00fc&#8217;ndeki ara\u015ft\u0131rmac\u0131lar, SHAttered ad\u0131n\u0131 verdikleri bir sald\u0131r\u0131 ile iki farkl\u0131 PDF dosyas\u0131n\u0131n ayn\u0131 SHA-1 \u00f6zetine sahip olabilece\u011fini pratik olarak kan\u0131tlad\u0131lar. Bu, farkl\u0131 i\u00e7eriklere sahip iki belgenin ayn\u0131 &#8220;dijital parmak izine&#8221; sahip olabilece\u011fi anlam\u0131na geliyordu. Bu durum, sahte bir dijital imzan\u0131n veya k\u00f6t\u00fc ama\u00e7l\u0131 bir yaz\u0131l\u0131m\u0131n, me\u015fru bir yaz\u0131l\u0131mm\u0131\u015f gibi ayn\u0131 hash de\u011ferine sahip olmas\u0131n\u0131 sa\u011flayarak g\u00fcvenlik sistemlerini aldatma potansiyeli ta\u015f\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Tarayicilar-ve-Sertifika-Otoriteleri-Tarafindan-Neden-Terk-Edildi\"><\/span>Taray\u0131c\u0131lar ve Sertifika Otoriteleri Taraf\u0131ndan Neden Terk Edildi?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHAttered sald\u0131r\u0131s\u0131n\u0131n pratik olarak m\u00fcmk\u00fcn oldu\u011funun kan\u0131tlanmas\u0131, dijital g\u00fcvenlik d\u00fcnyas\u0131nda b\u00fcy\u00fck bir alarm etkisi yaratt\u0131. Google, Mozilla, Microsoft gibi b\u00fcy\u00fck taray\u0131c\u0131 \u00fcreticileri, SHA-1 ile imzalanm\u0131\u015f SSL\/TLS sertifikalar\u0131n\u0131 kullanan web sitelerini &#8220;g\u00fcvenli de\u011fil&#8221; olarak i\u015faretlemeye ba\u015flad\u0131. Sertifika Otoriteleri (CA&#8217;ler) ise 2016&#8217;dan itibaren SHA-1 tabanl\u0131 yeni sertifika vermeyi durdurdu. Bu radikal ad\u0131m\u0131n nedeni, kullan\u0131c\u0131lar\u0131 korumakt\u0131. Bir sald\u0131rgan, g\u00fcvenilir bir web sitesi i\u00e7in d\u00fczenlenmi\u015f bir sertifikan\u0131n hash de\u011feriyle ayn\u0131 de\u011fere sahip sahte bir sertifika olu\u015fturarak kullan\u0131c\u0131lar\u0131 sahte sitelere y\u00f6nlendirebilir ve &#8220;ortadaki adam&#8221; (man-in-the-middle) sald\u0131r\u0131lar\u0131 ger\u00e7ekle\u015ftirebilirdi. Bu nedenle, t\u00fcm end\u00fcstri daha g\u00fcvenli olan SHA-2 ailesi algoritmalar\u0131na ge\u00e7i\u015f yapt\u0131.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"SHA-256-Algoritmasi-Gunumuzun-Endustri-Standardi\"><\/span>SHA-256 Algoritmas\u0131: G\u00fcn\u00fcm\u00fcz\u00fcn End\u00fcstri Standard\u0131<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>SHA-1&#8217;in g\u00fcvenlik zafiyetlerinin ortaya \u00e7\u0131kmas\u0131yla birlikte, dijital g\u00fcvenlik d\u00fcnyas\u0131 h\u0131zla daha g\u00fc\u00e7l\u00fc ve diren\u00e7li bir alternatife y\u00f6neldi: SHA-2 ailesi ve bu ailenin en pop\u00fcler \u00fcyesi olan SHA-256. G\u00fcn\u00fcm\u00fczde SSL\/TLS sertifikalar\u0131ndan blokzincir teknolojilerine kadar geni\u015f bir yelpazede kullan\u0131lan SHA-256, modern g\u00fcvenli\u011fin temel standard\u0131 haline gelmi\u015ftir.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"SHA-2-Ailesi-ve-SHA-256-Nedir\"><\/span>SHA-2 Ailesi ve SHA-256 Nedir?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-2, yine NSA taraf\u0131ndan tasarlanan ve 2001 y\u0131l\u0131nda yay\u0131nlanan bir kriptografik hash fonksiyonlar\u0131 setidir. Bu aile, farkl\u0131 \u00e7\u0131kt\u0131 uzunluklar\u0131na sahip birka\u00e7 algoritma i\u00e7erir: SHA-224, SHA-256, SHA-384 ve SHA-512. \u0130simlerindeki say\u0131lar, \u00fcrettikleri \u00f6zetin bit cinsinden uzunlu\u011funu belirtir. SHA-256, bu aile i\u00e7inde g\u00fcvenlik ve performans dengesi a\u00e7\u0131s\u0131ndan en yayg\u0131n olarak benimsenen algoritmad\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Teknik-Yapisi-ve-Guvenlik-Mekanizmalari-256-bit-Cikti\"><\/span>Teknik Yap\u0131s\u0131 ve G\u00fcvenlik Mekanizmalar\u0131 (256-bit \u00c7\u0131kt\u0131)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-256, SHA-1&#8217;e benzer bir yap\u0131ya sahip olsa da, hem matematiksel olarak daha karma\u015f\u0131k hem de daha g\u00fcvenlidir. En temel fark, \u00fcretti\u011fi \u00f6zetin uzunlu\u011fudur. SHA-1&#8217;in 160-bit&#8217;lik \u00e7\u0131kt\u0131s\u0131na kar\u015f\u0131l\u0131k SHA-256, 256-bit (64 onalt\u0131l\u0131k karakter) uzunlu\u011funda bir \u00f6zet \u00fcretir. Bu daha uzun \u00f6zet, kaba kuvvet (brute-force) ve \u00e7ak\u0131\u015fma sald\u0131r\u0131lar\u0131na kar\u015f\u0131 \u00e7ok daha y\u00fcksek bir diren\u00e7 sa\u011flar. 2^160 olas\u0131l\u0131\u011fa k\u0131yasla 2^256 olas\u0131l\u0131\u011f\u0131 k\u0131rmak, g\u00fcn\u00fcm\u00fcz teknolojisiyle pratik olarak imkans\u0131zd\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"SHA-1e-Gore-Ustunlukleri-ve-Guvenlik-Farklari\"><\/span>SHA-1&#8217;e G\u00f6re \u00dcst\u00fcnl\u00fckleri ve G\u00fcvenlik Farklar\u0131<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-256&#8217;n\u0131n SHA-1&#8217;e g\u00f6re en b\u00fcy\u00fck \u00fcst\u00fcnl\u00fc\u011f\u00fc, kan\u0131tlanm\u0131\u015f \u00e7ak\u0131\u015fma direncidir. SHA-1&#8217;de pratik olarak bir \u00e7ak\u0131\u015fma bulunabilirken, SHA-256 i\u00e7in hen\u00fcz bilinen veya pratik bir \u00e7ak\u0131\u015fma sald\u0131r\u0131s\u0131 y\u00f6ntemi yoktur. \u00d6zet uzunlu\u011funun artmas\u0131, potansiyel olarak bulunabilecek \u00e7ak\u0131\u015fma say\u0131s\u0131n\u0131 astronomik d\u00fczeyde azalt\u0131r. Bu da onu dijital imzalar, veri b\u00fct\u00fcnl\u00fc\u011f\u00fc ve kimlik do\u011frulama gibi kritik uygulamalar i\u00e7in \u00e7ok daha g\u00fcvenilir bir se\u00e7enek haline getirir.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"SSLTLS-Sertifikalarinda-ve-Modern-Uygulamalardaki-Yeri\"><\/span>SSL\/TLS Sertifikalar\u0131nda ve Modern Uygulamalardaki Yeri<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Bug\u00fcn, g\u00fcvenli bir web sitesini ziyaret etti\u011finizde taray\u0131c\u0131n\u0131z\u0131n adres \u00e7ubu\u011funda g\u00f6rd\u00fc\u011f\u00fcn\u00fcz kilit simgesi, b\u00fcy\u00fck olas\u0131l\u0131kla SHA-256 ile imzalanm\u0131\u015f bir <a href=\"https:\/\/www.ihs.com.tr\/ssl\/ssl-sertifikasi-turleri-nelerdir\/\" target=\"_blank\">SSL sertifikas\u0131<\/a> sayesinde oradad\u0131r. T\u00fcm sayg\u0131n Sertifika Otoriteleri, sertifikalar\u0131n\u0131 imzalamak i\u00e7in SHA-256 veya daha g\u00fc\u00e7l\u00fc algoritmalar\u0131 kullan\u0131r. Ayr\u0131ca, Bitcoin gibi bir\u00e7ok kripto para biriminin temelini olu\u015fturan blokzincir teknolojisi de i\u015flemlerin ve bloklar\u0131n b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc sa\u011flamak i\u00e7in SHA-256&#8217;ya g\u00fcvenir. Yaz\u0131l\u0131m da\u011f\u0131t\u0131m\u0131, e-posta g\u00fcvenli\u011fi ve veritaban\u0131 b\u00fct\u00fcnl\u00fc\u011f\u00fc gibi say\u0131s\u0131z modern uygulamada da end\u00fcstri standard\u0131 olarak kabul edilmektedir.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"SHA-3-Algoritmasi-Gelecegin-Guvenlik-Mimarisi\"><\/span>SHA-3 Algoritmas\u0131: Gelece\u011fin G\u00fcvenlik Mimarisi<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>SHA-1&#8217;in k\u0131r\u0131lmas\u0131 ve SHA-2&#8217;nin de teorik olarak benzer bir yap\u0131ya sahip olmas\u0131, kriptografi toplulu\u011funu proaktif bir ad\u0131m atmaya y\u00f6neltti. Olas\u0131 bir gelecekte SHA-2&#8217;de de bir zafiyet bulunmas\u0131 riskine kar\u015f\u0131, tamamen farkl\u0131 bir mimariye sahip yeni nesil bir hash standard\u0131 geli\u015ftirildi: SHA-3.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"SHA-3-Nedir-ve-Gelistirilme-Amaci\"><\/span>SHA-3 Nedir ve Geli\u015ftirilme Amac\u0131<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-3 (Secure Hash Algorithm 3), ABD Ulusal Standartlar ve Teknoloji Enstit\u00fcs\u00fc (NIST) taraf\u0131ndan d\u00fczenlenen halka a\u00e7\u0131k bir yar\u0131\u015fma sonucunda se\u00e7ilen ve 2015 y\u0131l\u0131nda standartla\u015ft\u0131r\u0131lan en yeni hash algoritmas\u0131d\u0131r. Geli\u015ftirilmesindeki temel ama\u00e7, SHA-2&#8217;nin yerini almak de\u011fil, ona g\u00fc\u00e7l\u00fc ve yap\u0131sal olarak farkl\u0131 bir alternatif sunmakt\u0131. B\u00f6ylece, e\u011fer SHA-2&#8217;nin temelini olu\u015fturan Merkle\u2013Damg\u00e5rd yap\u0131s\u0131nda bir zafiyet bulunursa, d\u00fcnya h\u0131zla tamamen farkl\u0131 ve bu zafiyetten etkilenmeyen bir algoritmaya ge\u00e7ebilecektir. Bu yakla\u015f\u0131m, <a href=\"https:\/\/www.ihs.com.tr\/blog\/sunucunuzun-yedeklenmesi-icin-en-iyi-stratejiler-backup-solutions\/\" target=\"_blank\">kriptografik \u00e7eviklik (crypto-agility)<\/a> ilkesinin bir par\u00e7as\u0131d\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Temelindeki-%E2%80%9CKeccak%E2%80%9D-Algoritmasi-ve-Yapisal-Farkliliklari\"><\/span>Temelindeki &#8220;Keccak&#8221; Algoritmas\u0131 ve Yap\u0131sal Farkl\u0131l\u0131klar\u0131<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-3, yar\u0131\u015fmay\u0131 kazanan &#8220;Keccak&#8221; adl\u0131 algoritmay\u0131 temel al\u0131r. SHA-1 ve SHA-2&#8217;nin aksine, Keccak, &#8220;s\u00fcnger yap\u0131s\u0131&#8221; (sponge construction) ad\u0131 verilen tamamen farkl\u0131 bir tasar\u0131m felsefesi kullan\u0131r. Bu yap\u0131da, veri bloklar\u0131 bir s\u00fcngerin suyu emmesi gibi &#8220;emilir&#8221; ve ard\u0131ndan istenen uzunlukta bir \u00e7\u0131kt\u0131 \u00fcretmek i\u00e7in &#8220;s\u0131k\u0131l\u0131r&#8221;. Bu yap\u0131sal farkl\u0131l\u0131k, SHA-2&#8217;yi etkileyebilecek potansiyel sald\u0131r\u0131 t\u00fcrlerine (\u00f6rne\u011fin, uzunluk geni\u015fletme sald\u0131r\u0131lar\u0131) kar\u015f\u0131 do\u011fal bir ba\u011f\u0131\u015f\u0131kl\u0131k sa\u011flar.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"SHA-2den-Farkli-Tasarimi-ve-Potansiyel-Avantajlari\"><\/span>SHA-2&#8217;den Farkl\u0131 Tasar\u0131m\u0131 ve Potansiyel Avantajlar\u0131<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-3&#8217;\u00fcn en b\u00fcy\u00fck avantaj\u0131, yap\u0131sal olarak SHA-2&#8217;den tamamen ba\u011f\u0131ms\u0131z olmas\u0131d\u0131r. Bu, kriptografik bir \u00e7e\u015fitlilik sunar. Performans a\u00e7\u0131s\u0131ndan, genel ama\u00e7l\u0131 yaz\u0131l\u0131mlarda SHA-256 genellikle daha h\u0131zl\u0131 \u00e7al\u0131\u015f\u0131rken, SHA-3 \u00f6zellikle donan\u0131m uygulamalar\u0131nda (\u00f6rne\u011fin, \u00f6zel \u00e7ip tasar\u0131mlar\u0131nda) y\u00fcksek verimlilik ve performans sergilemek \u00fczere tasarlanm\u0131\u015ft\u0131r. Ayr\u0131ca, esnek \u00e7\u0131kt\u0131 uzunluklar\u0131 sunabilmesi, onu farkl\u0131 g\u00fcvenlik ihtiya\u00e7lar\u0131na kolayca adapte edilebilir k\u0131lar.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Gunumuzdeki-Adaptasyon-Sureci-ve-Gelecekteki-Rolu\"><\/span>G\u00fcn\u00fcm\u00fczdeki Adaptasyon S\u00fcreci ve Gelecekteki Rol\u00fc<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-2 \u015fu an i\u00e7in son derece g\u00fcvenli kabul edildi\u011finden, SHA-3&#8217;\u00fcn yayg\u0131n adaptasyonu yava\u015f ilerlemektedir. Hen\u00fcz SSL\/TLS sertifikalar\u0131 gibi alanlarda yayg\u0131n olarak kullan\u0131lmamaktad\u0131r. Ancak, y\u00fcksek g\u00fcvenlik gerektiren baz\u0131 \u00f6zel sekt\u00f6rlerde ve yeni geli\u015ftirilen protokollerde tercih edilmeye ba\u015flanm\u0131\u015ft\u0131r. SHA-3, bug\u00fcn i\u00e7in bir &#8220;yedek lastik&#8221; gibi g\u00f6r\u00fclebilir. \u015eu anki lastik (SHA-2) sa\u011flam olsa da, gelecekte herhangi bir sorun ya\u015fanmas\u0131 durumunda, dijital d\u00fcnyan\u0131n g\u00fcvenle yoluna devam etmesini sa\u011flayacak olan haz\u0131r ve test edilmi\u015f bir alternatiftir.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Hash-Algoritmalarinin-Karsilastirmali-Analizi\"><\/span>Hash Algoritmalar\u0131n\u0131n Kar\u015f\u0131la\u015ft\u0131rmal\u0131 Analizi<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>SHA-1, SHA-256 ve SHA-3 algoritmalar\u0131n\u0131n her biri, dijital g\u00fcvenli\u011fin farkl\u0131 d\u00f6nemlerini ve felsefelerini temsil eder. Bu algoritmalar\u0131 g\u00fcvenlik, \u00e7\u0131kt\u0131 uzunlu\u011fu, performans ve tasar\u0131mlar\u0131 a\u00e7\u0131s\u0131ndan kar\u015f\u0131la\u015ft\u0131rmak, aralar\u0131ndaki temel farklar\u0131 ve neden birinin di\u011ferine tercih edildi\u011fini daha net anlamam\u0131z\u0131 sa\u011flar.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Guvenlik-Seviyeleri-ve-Saldirilara-Karsi-Direnc\"><\/span>G\u00fcvenlik Seviyeleri ve Sald\u0131r\u0131lara Kar\u015f\u0131 Diren\u00e7<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>G\u00fcvenlik, bir hash algoritmas\u0131 i\u00e7in en kritik \u00f6l\u00e7\u00fctt\u00fcr. SHA-1, pratik \u00e7ak\u0131\u015fma sald\u0131r\u0131lar\u0131 nedeniyle art\u0131k &#8220;g\u00fcvensiz&#8221; olarak kabul edilmektedir. SHA-256 ise \u015fu anki end\u00fcstri standard\u0131d\u0131r ve bilinen pratik bir sald\u0131r\u0131ya kar\u015f\u0131 dayan\u0131kl\u0131d\u0131r, bu da onu son derece g\u00fcvenli k\u0131lar. SHA-3, tamamen farkl\u0131 bir yap\u0131ya sahip oldu\u011fu i\u00e7in SHA-2&#8217;yi etkileyebilecek teorik sald\u0131r\u0131 s\u0131n\u0131flar\u0131na kar\u015f\u0131 bile diren\u00e7 sunar ve en y\u00fcksek g\u00fcvenlik seviyesini temsil eder.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Cikti-Ozet-Uzunluklari-160-bit-vs-256-bit-vs-Degisken-Uzunluk\"><\/span>\u00c7\u0131kt\u0131 (\u00d6zet) Uzunluklar\u0131: 160-bit vs 256-bit vs De\u011fi\u015fken Uzunluk<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u00c7\u0131kt\u0131 uzunlu\u011fu, bir algoritman\u0131n kaba kuvvet sald\u0131r\u0131lar\u0131na kar\u015f\u0131 direncini do\u011frudan etkiler. SHA-1&#8217;in 160-bit&#8217;lik \u00e7\u0131kt\u0131s\u0131 g\u00fcn\u00fcm\u00fcz standartlar\u0131nda yetersiz kal\u0131rken, SHA-256&#8217;n\u0131n 256-bit&#8217;lik \u00e7\u0131kt\u0131s\u0131 g\u00fc\u00e7l\u00fc bir g\u00fcvenlik seviyesi sunar. SHA-2 ailesi 384 ve 512-bit gibi daha uzun se\u00e7enekler de sunar. SHA-3 ise standart olarak SHA-2 ile ayn\u0131 \u00e7\u0131kt\u0131 uzunluklar\u0131n\u0131 (224, 256, 384, 512) desteklemekle birlikte, tasar\u0131m\u0131n\u0131n esnekli\u011fi sayesinde teorik olarak herhangi bir uzunlukta \u00e7\u0131kt\u0131 \u00fcretebilir.<\/p>\n<div class=\"karsilastirma\">\n<table>\n<thead>\n<tr>\n<th>\u00d6zellik<\/th>\n<th>SHA-1<\/th>\n<th>SHA-256 (SHA-2 Ailesi)<\/th>\n<th>SHA-3<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><b>\u00c7\u0131kt\u0131 Uzunlu\u011fu<\/b><\/td>\n<td>160-bit<\/td>\n<td>256-bit (Ayr\u0131ca 224, 384, 512-bit)<\/td>\n<td>De\u011fi\u015fken (Genellikle 256, 384, 512-bit)<\/td>\n<\/tr>\n<tr>\n<td><b>G\u00fcvenlik Durumu<\/b><\/td>\n<td>G\u00fcvensiz (K\u0131r\u0131ld\u0131)<\/td>\n<td>G\u00fcvenli (End\u00fcstri Standard\u0131)<\/td>\n<td>\u00c7ok G\u00fcvenli (Gelece\u011fe D\u00f6n\u00fck)<\/td>\n<\/tr>\n<tr>\n<td><b>\u00c7ak\u0131\u015fma Direnci<\/b><\/td>\n<td>Zay\u0131f (Pratik sald\u0131r\u0131 mevcut)<\/td>\n<td>G\u00fc\u00e7l\u00fc (Bilinen pratik sald\u0131r\u0131 yok)<\/td>\n<td>\u00c7ok G\u00fc\u00e7l\u00fc<\/td>\n<\/tr>\n<tr>\n<td><b>Temel Yap\u0131<\/b><\/td>\n<td>Merkle\u2013Damg\u00e5rd<\/td>\n<td>Merkle\u2013Damg\u00e5rd<\/td>\n<td>S\u00fcnger Yap\u0131s\u0131 (Keccak)<\/td>\n<\/tr>\n<tr>\n<td><b>Yayg\u0131nl\u0131k<\/b><\/td>\n<td>Eski sistemler (Kullan\u0131mdan kald\u0131r\u0131ld\u0131)<\/td>\n<td>\u00c7ok yayg\u0131n (SSL, Bitcoin vb.)<\/td>\n<td>S\u0131n\u0131rl\u0131 (Y\u00fcksek g\u00fcvenlikli uygulamalar)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h3><span class=\"ez-toc-section\" id=\"Performans-ve-Hiz-Farkliliklari\"><\/span>Performans ve H\u0131z Farkl\u0131l\u0131klar\u0131<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Performans, algoritman\u0131n ne kadar h\u0131zl\u0131 bir \u015fekilde hash \u00fcretebildi\u011fini ifade eder. Genellikle, daha karma\u015f\u0131k ve g\u00fcvenli algoritmalar daha yava\u015ft\u0131r. Ancak bu her zaman ge\u00e7erli de\u011fildir. Modern i\u015flemcilerde SHA-256, SHA-1&#8217;den bile daha h\u0131zl\u0131 \u00e7al\u0131\u015fabilir \u00e7\u00fcnk\u00fc yeni nesil CPU&#8217;lar SHA-2 i\u00e7in optimize edilmi\u015f komut setleri (SHA uzant\u0131lar\u0131) i\u00e7erir. SHA-3, yaz\u0131l\u0131m tabanl\u0131 uygulamalarda genellikle SHA-256&#8217;dan biraz daha yava\u015ft\u0131r. Fakat donan\u0131m tabanl\u0131 uygulamalar i\u00e7in tasarland\u0131\u011f\u0131ndan, \u00f6zel entegre devrelerde (ASIC) veya FPGA&#8217;lerde olduk\u00e7a y\u00fcksek performans sunabilir.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Algoritmik-Yapi-ve-Tasarim-Felsefeleri\"><\/span>Algoritmik Yap\u0131 ve Tasar\u0131m Felsefeleri<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>En temel yap\u0131sal fark, SHA-1 ve SHA-2&#8217;nin Merkle\u2013Damg\u00e5rd yap\u0131s\u0131n\u0131 kullan\u0131rken, SHA-3&#8217;\u00fcn S\u00fcnger Yap\u0131s\u0131&#8217;n\u0131 kullanmas\u0131d\u0131r. Merkle\u2013Damg\u00e5rd yap\u0131s\u0131, girdiyi bloklara b\u00f6l\u00fcp s\u0131rayla i\u015fler. Bu yap\u0131, &#8220;uzunluk geni\u015fletme&#8221; (length extension) gibi baz\u0131 teorik sald\u0131r\u0131lara kar\u015f\u0131 savunmas\u0131z olabilir. \u00d6te yandan, SHA-3&#8217;\u00fcn s\u00fcnger yap\u0131s\u0131 bu t\u00fcr sald\u0131r\u0131lara kar\u015f\u0131 do\u011fas\u0131 gere\u011fi ba\u011f\u0131\u015f\u0131kt\u0131r ve daha modern bir kriptografik tasar\u0131m olarak kabul edilir. Bu tasar\u0131m \u00e7e\u015fitlili\u011fi, bir yap\u0131 t\u00fcr\u00fcnde ke\u015ffedilebilecek bir zafiyetin t\u00fcm standartlar\u0131 etkilemesini \u00f6nler.<\/p>\n<div class=\"karsilastirma\">\n<table>\n<thead>\n<tr>\n<th>Kar\u015f\u0131la\u015ft\u0131rma Alan\u0131<\/th>\n<th>A\u00e7\u0131klama ve Kar\u015f\u0131la\u015ft\u0131rma<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><b>Tasar\u0131m Felsefesi<\/b><\/td>\n<td><b>SHA-1\/SHA-2:<\/b> Gelirimsel bir yakla\u015f\u0131m sergilerler. SHA-2, SHA-1&#8217;in tasar\u0131m\u0131n\u0131 daha b\u00fcy\u00fck say\u0131lar ve daha karma\u015f\u0131k fonksiyonlarla g\u00fc\u00e7lendirir. Her ikisi de Merkle-Damg\u00e5rd yap\u0131s\u0131n\u0131 kullan\u0131r.<br \/><b>SHA-3:<\/b> Devrimsel bir yakla\u015f\u0131md\u0131r. Olas\u0131 bir teorik zafiyete kar\u015f\u0131 tamamen farkl\u0131 bir yap\u0131 olan S\u00fcnger Yap\u0131s\u0131&#8217;n\u0131 (Keccak) temel al\u0131r.<\/td>\n<\/tr>\n<tr>\n<td><b>Kullan\u0131m Alan\u0131 \u00d6nceli\u011fi<\/b><\/td>\n<td><b>SHA-1:<\/b> Art\u0131k kullan\u0131lmamal\u0131d\u0131r.<br \/><b>SHA-256:<\/b> SSL\/TLS sertifikalar\u0131, kod imzalama, blokzincir, parola saklama gibi genel ama\u00e7l\u0131 yaz\u0131l\u0131m uygulamalar\u0131 i\u00e7in mevcut standartt\u0131r.<br \/><b>SHA-3:<\/b> Y\u00fcksek performansl\u0131 donan\u0131m entegrasyonlar\u0131, g\u00f6m\u00fcl\u00fc sistemler ve gelece\u011fe d\u00f6n\u00fck g\u00fcvenlik protokolleri i\u00e7in idealdir.<\/td>\n<\/tr>\n<tr>\n<td><b>Sald\u0131r\u0131 Direnci<\/b><\/td>\n<td><b>SHA-1:<\/b> \u00c7ak\u0131\u015fma sald\u0131r\u0131lar\u0131na kar\u015f\u0131 k\u0131r\u0131lgand\u0131r.<br \/><b>SHA-2:<\/b> Bilinen t\u00fcm pratik sald\u0131r\u0131lara kar\u015f\u0131 g\u00fc\u00e7l\u00fcd\u00fcr.<br \/><b>SHA-3:<\/b> SHA-2&#8217;ye kar\u015f\u0131 etkili olabilecek teorik sald\u0131r\u0131 s\u0131n\u0131flar\u0131na (\u00f6rn. uzunluk geni\u015fletme) kar\u015f\u0131 da do\u011fal olarak diren\u00e7lidir.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h2><span class=\"ez-toc-section\" id=\"SSLTLS-Sertifikalarinda-Hash-Algoritmalarinin-Kritik-Rolu\"><\/span>SSL\/TLS Sertifikalar\u0131nda Hash Algoritmalar\u0131n\u0131n Kritik Rol\u00fc<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Bir web sitesini ziyaret etti\u011finizde taray\u0131c\u0131n\u0131z ile <a href=\"https:\/\/www.ihs.com.tr\/sunucu-kiralama\/\" target=\"_blank\">sunucu<\/a> aras\u0131ndaki ba\u011flant\u0131y\u0131 g\u00fcvence alt\u0131na alan SSL\/TLS sertifikalar\u0131, g\u00fcvenilirli\u011fini b\u00fcy\u00fck \u00f6l\u00e7\u00fcde hash algoritmalar\u0131na bor\u00e7ludur. Bu algoritmalar, dijital imza s\u00fcrecinin merkezinde yer alarak veri b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc ve kimlik do\u011frulamas\u0131n\u0131 sa\u011flar.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Dijital-Imza-Nedir-ve-Hash-Algoritmasi-Nasil-Kullanilir\"><\/span>Dijital \u0130mza Nedir ve Hash Algoritmas\u0131 Nas\u0131l Kullan\u0131l\u0131r?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Dijital imza, elektronik bir belgenin veya mesaj\u0131n orijinalli\u011fini ve b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc kan\u0131tlayan matematiksel bir tekniktir. S\u00fcre\u00e7 \u015fu \u015fekilde i\u015fler: \u0130lk olarak, sertifika bilgileri gibi imzalanacak olan verinin tamam\u0131 bir hash algoritmas\u0131 (\u00f6rne\u011fin, SHA-256) kullan\u0131larak \u00f6zetlenir. Daha sonra, bu k\u0131sa ve benzersiz hash de\u011feri, sertifikay\u0131 d\u00fczenleyen kurumun (Sertifika Otoritesi) \u00f6zel anahtar\u0131 (private key) ile \u015fifrelenir. Bu \u015fifrelenmi\u015f hash, dijital imzad\u0131r. Bir taray\u0131c\u0131 bu sertifikay\u0131 ald\u0131\u011f\u0131nda, imzan\u0131n \u015fifresini Sertifika Otoritesinin genel anahtar\u0131 (public key) ile \u00e7\u00f6zer ve orijinal hash de\u011ferini elde eder. Ard\u0131ndan taray\u0131c\u0131, sertifika bilgilerinin tamam\u0131n\u0131 ayn\u0131 hash algoritmas\u0131 ile kendisi de \u00f6zetler. E\u011fer iki hash de\u011feri e\u015fle\u015firse, sertifikan\u0131n g\u00fcvenilir bir kaynaktan geldi\u011fi ve yolda de\u011fi\u015ftirilmedi\u011fi do\u011frulanm\u0131\u015f olur.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Sertifika-Otoritesi-CA-Imzalama-Sureci\"><\/span>Sertifika Otoritesi (CA) \u0130mzalama S\u00fcreci<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Bir web sitesi sahibi bir <a href=\"https:\/\/www.ihs.com.tr\/ssl\/ssl-sertifikasi-nedir-onemlidir\/\" target=\"_blank\">SSL sertifikas\u0131<\/a> ba\u015fvurusu yapt\u0131\u011f\u0131nda, Sertifika Otoritesi (CA), ba\u015fvuru sahibinin kimli\u011fini ve <a href=\"https:\/\/www.ihs.com.tr\/domain\/alan-adi-domain-tescili.html\" target=\"_blank\">alan ad\u0131<\/a> sahipli\u011fini do\u011frular. Do\u011frulama tamamland\u0131ktan sonra, CA, web sitesinin bilgilerini (alan ad\u0131, \u015firket bilgileri, genel anahtar vb.) i\u00e7eren bir sertifika dosyas\u0131 olu\u015fturur. \u0130\u015fte bu dosyan\u0131n b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc garanti etmek i\u00e7in CA, yukar\u0131da anlat\u0131lan dijital imza s\u00fcrecini kullanarak sertifikay\u0131 kendi \u00f6zel anahtar\u0131yla imzalar. Bu imza i\u00e7in SHA-256 gibi g\u00fc\u00e7l\u00fc bir hash algoritmas\u0131 kullan\u0131lmas\u0131, t\u00fcm g\u00fcvenlik zincirinin sa\u011flaml\u0131\u011f\u0131 i\u00e7in kritiktir.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Guven-Zincirinde-Chain-of-Trust-Veri-Butunlugunun-Saglanmasi\"><\/span>G\u00fcven Zincirinde (Chain of Trust) Veri B\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fcn Sa\u011flanmas\u0131<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SSL g\u00fcvenli\u011fi, bir &#8220;g\u00fcven zinciri&#8221; (chain of trust) \u00fczerine kuruludur. Taray\u0131c\u0131n\u0131z, do\u011frudan bir web sitesinin sertifikas\u0131na g\u00fcvenmez. Bunun yerine, o sertifikay\u0131 imzalayan arac\u0131 CA&#8217;ya, o arac\u0131 CA&#8217;y\u0131 imzalayan k\u00f6k CA&#8217;ya g\u00fcvenir. Bu k\u00f6k CA&#8217;lar\u0131n sertifikalar\u0131 ise i\u015fletim sistemleri ve taray\u0131c\u0131lar taraf\u0131ndan \u00f6nceden y\u00fcklenmi\u015f ve g\u00fcvenilir olarak kabul edilmi\u015ftir. Zincirdeki her bir sertifika, bir \u00fcst\u00fcndeki sertifika taraf\u0131ndan dijital olarak imzalan\u0131r. Hash algoritmalar\u0131, bu zincirin her halkas\u0131nda veri b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fc sa\u011flar. E\u011fer zincirdeki herhangi bir sertifika de\u011fi\u015ftirilirse, hash de\u011feri uyu\u015fmayacak ve taray\u0131c\u0131 &#8220;g\u00fcvenli olmayan ba\u011flant\u0131&#8221; hatas\u0131 verecektir.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Bir-Web-Sitesinin-Kullandigi-Imza-Algoritmasi-Nasil-Kontrol-Edilir\"><\/span>Bir Web Sitesinin Kulland\u0131\u011f\u0131 \u0130mza Algoritmas\u0131 Nas\u0131l Kontrol Edilir?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Bir web sitesinin hangi hash algoritmas\u0131yla imzalanm\u0131\u015f bir SSL sertifikas\u0131 kulland\u0131\u011f\u0131n\u0131 kolayca kontrol edebilirsiniz. \u00c7o\u011fu modern taray\u0131c\u0131da (Google Chrome, Firefox vb.) adres \u00e7ubu\u011fundaki kilit simgesine t\u0131klay\u0131n. A\u00e7\u0131lan men\u00fcden &#8220;Ba\u011flant\u0131 g\u00fcvenli&#8221; veya &#8220;Sertifika ge\u00e7erli&#8221; gibi bir se\u00e7ene\u011fi se\u00e7erek sertifika detaylar\u0131n\u0131 g\u00f6r\u00fcnt\u00fcleyin. Sertifika g\u00f6r\u00fcnt\u00fcleyicisinde, &#8220;Ayr\u0131nt\u0131lar&#8221; sekmesine giderek &#8220;\u0130mza Algoritmas\u0131&#8221; veya &#8220;Signature Algorithm&#8221; alan\u0131n\u0131 bulun. Burada &#8220;sha256WithRSAEncryption&#8221; veya benzeri bir ifade g\u00f6receksiniz. Bu, sertifikan\u0131n imzalama s\u00fcrecinde SHA-256 algoritmas\u0131n\u0131n kullan\u0131ld\u0131\u011f\u0131n\u0131 g\u00f6sterir.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Dogru-Hash-Algoritmasini-Secmenin-Onemi\"><\/span>Do\u011fru Hash Algoritmas\u0131n\u0131 Se\u00e7menin \u00d6nemi<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Dijital d\u00fcnyada g\u00fcvenlik, en zay\u0131f halkas\u0131 kadar g\u00fc\u00e7l\u00fcd\u00fcr. Kriptografik sistemlerde bu en zay\u0131f halkalardan biri, kullan\u0131lan hash algoritmas\u0131 olabilir. Eski ve g\u00fcvensiz bir algoritma kullanmak, en karma\u015f\u0131k g\u00fcvenlik sistemlerini bile anlams\u0131z k\u0131labilir. Bu nedenle, do\u011fru ve g\u00fcncel hash algoritmas\u0131n\u0131 se\u00e7mek yaln\u0131zca bir teknik detay de\u011fil, ayn\u0131 zamanda temel bir g\u00fcvenlik zorunlulu\u011fudur.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Neden-SHA-256-veya-Uzeri-Algoritmalar-Tercih-Edilmeli\"><\/span>Neden SHA-256 veya \u00dczeri Algoritmalar Tercih Edilmeli?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-256 ve SHA-3 gibi modern algoritmalar, bilinen t\u00fcm pratik sald\u0131r\u0131lara kar\u015f\u0131 kan\u0131tlanm\u0131\u015f bir diren\u00e7 sunar. Onlar\u0131 tercih etmenin temel nedenleri \u015funlard\u0131r:<\/p>\n<ul>\n<li><b>\u00c7ak\u0131\u015fma Direnci:<\/b> SHA-1&#8217;in aksine, bu algoritmalarda iki farkl\u0131 girdinin ayn\u0131 \u00f6zeti \u00fcretmesi (\u00e7ak\u0131\u015fma) pratik olarak imkans\u0131zd\u0131r. Bu, dijital imzalar\u0131n ve veri b\u00fct\u00fcnl\u00fc\u011f\u00fc kontrollerinin g\u00fcvenilirli\u011fini garanti eder.<\/li>\n<li><b>End\u00fcstri Standard\u0131:<\/b> T\u00fcm b\u00fcy\u00fck teknoloji \u015firketleri, taray\u0131c\u0131lar, i\u015fletim sistemleri ve Sertifika Otoriteleri taraf\u0131ndan desteklenir ve zorunlu tutulur. Bu, geni\u015f bir uyumluluk ve g\u00fcvenilirlik sa\u011flar.<\/li>\n<li><b>Gelece\u011fe Uygunluk:<\/b> Kuantum bilgisayarlar gibi gelecekteki tehditler g\u00f6z \u00f6n\u00fcnde bulunduruldu\u011funda bile, 256-bit ve \u00fczeri \u00f6zet uzunluklar\u0131, daha uzun s\u00fcre g\u00fcvenli kalacak bir temel sunar.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Eski-Algoritmalari-Kullanmanin-Riskleri\"><\/span>Eski Algoritmalar\u0131 Kullanman\u0131n Riskleri<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SHA-1 gibi eski veya g\u00fcvenli\u011fi k\u0131r\u0131lm\u0131\u015f algoritmalar\u0131 kullanmaya devam etmek, sistemlerinizi ciddi risklere maruz b\u0131rak\u0131r. Bu risklerden baz\u0131lar\u0131 \u015funlard\u0131r:<\/p>\n<ul>\n<li><b>Sahte Dijital \u0130mzalar:<\/b> Sald\u0131rganlar, me\u015fru bir belgenin veya yaz\u0131l\u0131m\u0131n SHA-1 \u00f6zetiyle ayn\u0131 \u00f6zete sahip sahte bir versiyon olu\u015fturabilir. Bu, kullan\u0131c\u0131lar\u0131n k\u00f6t\u00fc ama\u00e7l\u0131 yaz\u0131l\u0131mlar\u0131 g\u00fcvenilir bir kaynaktan geliyormu\u015f gibi indirmesine neden olabilir.<\/li>\n<li><b>Man-in-the-Middle (Ortadaki Adam) Sald\u0131r\u0131lar\u0131:<\/b> Sahte bir SSL sertifikas\u0131 olu\u015fturularak, kullan\u0131c\u0131lar\u0131n ger\u00e7ek sand\u0131klar\u0131 sahte bir web sitesine y\u00f6nlendirilmesi ve t\u00fcm ileti\u015fimlerinin dinlenmesi m\u00fcmk\u00fcn hale gelebilir.<\/li>\n<li><b>Uyumluluk Sorunlar\u0131:<\/b> Modern taray\u0131c\u0131lar ve i\u015fletim sistemleri, SHA-1 kullanan sertifikalar\u0131 ve imzalar\u0131 art\u0131k reddetmektedir. Bu durum, hizmetlerinizin eri\u015filemez hale gelmesine yol a\u00e7ar.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Gelecege-Donuk-Kriptografik-Ceviklik-Crypto-Agility\"><\/span>Gelece\u011fe D\u00f6n\u00fck Kriptografik \u00c7eviklik (Crypto-Agility)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Kriptografik \u00e7eviklik, bir sistemin kulland\u0131\u011f\u0131 kriptografik algoritmalar\u0131 kolayca ve h\u0131zl\u0131 bir \u015fekilde g\u00fcncelleyebilme veya de\u011fi\u015ftirebilme yetene\u011fidir. Bug\u00fcn g\u00fcvenli olan SHA-256&#8217;n\u0131n bile gelecekte bir zafiyetinin bulunmas\u0131 ihtimaline kar\u015f\u0131 haz\u0131rl\u0131kl\u0131 olmak \u00f6nemlidir. Sistemlerinizi tasarlarken, hash algoritmas\u0131 gibi temel bile\u015fenleri &#8220;sabit kodlamak&#8221; yerine, yap\u0131land\u0131r\u0131labilir ve de\u011fi\u015ftirilebilir hale getirmek en iyi yakla\u015f\u0131md\u0131r. SHA-3&#8217;\u00fcn varl\u0131\u011f\u0131, bu \u00e7evikli\u011fin en g\u00fczel \u00f6rneklerinden biridir. SHA-2&#8217;de bir sorun \u00e7\u0131kmas\u0131 durumunda, sistemler h\u0131zla SHA-3&#8217;e ge\u00e7irilebilecek \u015fekilde tasarlanmal\u0131d\u0131r. Bu proaktif yakla\u015f\u0131m, uzun vadeli dijital g\u00fcvenli\u011fin anahtar\u0131d\u0131r.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Guvenli-SSL-Sertifikalari-Icin-Neden-IHS-Telekomu-Tercih-Etmelisiniz\"><\/span>G\u00fcvenli SSL Sertifikalar\u0131 \u0130\u00e7in Neden \u0130HS Telekom&#8217;u Tercih Etmelisiniz?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Web sitenizin ve kullan\u0131c\u0131lar\u0131n\u0131z\u0131n g\u00fcvenli\u011fini sa\u011flamak, dijital varl\u0131\u011f\u0131n\u0131z\u0131n en temel gereklili\u011fidir. G\u00fc\u00e7l\u00fc bir \u015fifreleme altyap\u0131s\u0131, ziyaret\u00e7ilerinizin verilerini korur, marka itibar\u0131n\u0131z\u0131 art\u0131r\u0131r ve arama motoru s\u0131ralamalar\u0131n\u0131za olumlu etki eder. Bu g\u00fcvenli\u011fin merkezinde ise modern ve sa\u011flam hash algoritmalar\u0131yla desteklenen SSL sertifikalar\u0131 yer al\u0131r. \u0130HS Telekom olarak, dijital g\u00fcvenli\u011finiz i\u00e7in en g\u00fcncel ve g\u00fcvenilir \u00e7\u00f6z\u00fcmleri sunuyoruz.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"En-Guncel-SHA-2-ve-Ustu-Algoritmalari-Destekleyen-Sertifikalar\"><\/span>En G\u00fcncel SHA-2 ve \u00dcst\u00fc Algoritmalar\u0131 Destekleyen Sertifikalar<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>G\u00fcvenlik standartlar\u0131 s\u00fcrekli geli\u015fmektedir. Art\u0131k g\u00fcvensiz kabul edilen SHA-1 gibi eski algoritmalar\u0131 geride b\u0131rakarak, t\u00fcm SSL sertifikalar\u0131m\u0131zda end\u00fcstri standard\u0131 olan SHA-256 ve daha g\u00fc\u00e7l\u00fc algoritmalar\u0131 kullan\u0131yoruz. Bu sayede, sitenizin kimlik do\u011frulamas\u0131n\u0131n ve veri b\u00fct\u00fcnl\u00fc\u011f\u00fcn\u00fcn en g\u00fcncel kriptografik koruma alt\u0131nda oldu\u011funu garanti ediyoruz. Taray\u0131c\u0131lar\u0131n ve g\u00fcvenlik otoritelerinin g\u00fcvendi\u011fi bu teknoloji ile ziyaret\u00e7ilerinize g\u00fcvenli bir gezinti deneyimi sunars\u0131n\u0131z.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Farkli-Ihtiyaclara-Yonelik-Genis-Sertifika-Portfoyu\"><\/span>Farkl\u0131 \u0130htiya\u00e7lara Y\u00f6nelik Geni\u015f Sertifika Portf\u00f6y\u00fc<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Her web sitesinin g\u00fcvenlik ihtiyac\u0131 farkl\u0131d\u0131r. Ki\u015fisel bir blog i\u00e7in gereken koruma ile b\u00fcy\u00fck bir e-ticaret platformu veya kurumsal bir site i\u00e7in gereken koruma ayn\u0131 de\u011fildir. \u0130HS Telekom olarak, bu farkl\u0131 ihtiya\u00e7lar\u0131 kar\u015f\u0131lamak \u00fczere geni\u015f bir sertifika yelpazesi sunuyoruz. Tek bir <a href=\"https:\/\/www.ihs.com.tr\/blog\/domain-nedir-ne-ise-yarar\/\" target=\"_blank\">domain<\/a> i\u00e7in temel koruma sa\u011flayan sertifikalardan, t\u00fcm alt alan adlar\u0131n\u0131z\u0131 koruyan <a href=\"https:\/\/www.ihs.com.tr\/ssl\/wildcard-ssl.html\" target=\"_blank\">Wildcard SSL<\/a> sertifikalar\u0131na ve en y\u00fcksek kurumsal do\u011frulama seviyesini sunan <a href=\"https:\/\/www.ihs.com.tr\/ssl\/ev-ssl.html\" target=\"_blank\">EV SSL<\/a> sertifikalar\u0131na kadar her \u00f6l\u00e7ekteki projeye uygun bir \u00e7\u00f6z\u00fcm\u00fcm\u00fcz bulunmaktad\u0131r. \u00d6zellikle <a href=\"https:\/\/www.ihs.com.tr\/web-hosting\/wordpress-hosting.html\" target=\"_blank\">WordPress hosting<\/a> kullanan siteler i\u00e7in de tam uyumlu ve kolay kurulabilir sertifikalar sa\u011fl\u0131yoruz.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Kolay-Kurulum-ve-Uzman-Teknik-Destek-Hizmeti\"><\/span>Kolay Kurulum ve Uzman Teknik Destek Hizmeti<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>SSL sertifikas\u0131 kurulumu teknik bir s\u00fcre\u00e7 olabilir. Ancak \u0130HS Telekom ile bu s\u00fcreci kolayca y\u00f6netebilirsiniz. M\u00fc\u015fteri panelimiz \u00fczerinden sertifikan\u0131z\u0131 basit ad\u0131mlarla kurabilir, <a href=\"https:\/\/www.ihs.com.tr\/web-hosting\/\" target=\"_blank\">hosting<\/a> paketinize entegre edebilirsiniz. Herhangi bir ad\u0131mda yard\u0131ma ihtiya\u00e7 duyman\u0131z halinde, alan\u0131nda uzman teknik destek ekibimiz size yol g\u00f6stermek ve t\u00fcm sorular\u0131n\u0131z\u0131 yan\u0131tlamak i\u00e7in haz\u0131rd\u0131r. Amac\u0131m\u0131z, en g\u00fc\u00e7l\u00fc g\u00fcvenli\u011fi en az teknik karma\u015f\u0131kl\u0131kla elde etmenizi sa\u011flamakt\u0131r.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Guclu-Sifreleme-ile-Web-Sitenizin-ve-Kullanicilarinizin-Guvenligini-Saglama\"><\/span>G\u00fc\u00e7l\u00fc \u015eifreleme ile Web Sitenizin ve Kullan\u0131c\u0131lar\u0131n\u0131z\u0131n G\u00fcvenli\u011fini Sa\u011flama<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0130HS Telekom&#8217;dan alaca\u011f\u0131n\u0131z bir SSL sertifikas\u0131, sadece adres \u00e7ubu\u011funuzda bir kilit simgesi g\u00f6stermekle kalmaz. Siteniz ile ziyaret\u00e7ileriniz aras\u0131ndaki t\u00fcm veri ak\u0131\u015f\u0131n\u0131 g\u00fc\u00e7l\u00fc bir \u015fekilde \u015fifreleyerek, kredi kart\u0131 bilgileri, parolalar ve ki\u015fisel veriler gibi hassas bilgilerin \u00fc\u00e7\u00fcnc\u00fc \u015fah\u0131slar\u0131n eline ge\u00e7mesini engeller. \u0130ster bir <a href=\"https:\/\/www.ihs.com.tr\/sunucu-kiralama\/vps-server.html\" target=\"_blank\">VPS<\/a> \u00fczerinde \u00e7al\u0131\u015fan bir uygulaman\u0131z, ister payla\u015f\u0131ml\u0131 hosting \u00fczerinde bar\u0131nan bir web siteniz olsun, do\u011fru SSL sertifikas\u0131 ile hem kendi dijital varl\u0131klar\u0131n\u0131z\u0131 hem de size g\u00fcvenen kullan\u0131c\u0131lar\u0131 en \u00fcst d\u00fczeyde koruma alt\u0131na alm\u0131\u015f olursunuz.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u0130nternet \u00fczerinde gezinirken, bir e-ticaret sitesinden al\u0131\u015fveri\u015f yaparken veya bankac\u0131l\u0131k i\u015flemlerinizi ger\u00e7ekle\u015ftirirken verilerinizin g\u00fcvenli\u011fi nas\u0131l sa\u011flan\u0131r? Bu g\u00fcvenli\u011fin temel ta\u015flar\u0131ndan biri, karma\u015f\u0131k&hellip;<\/p>\n","protected":false},"author":3,"featured_media":15810,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[400],"tags":[],"class_list":["post-15809","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ssl-sertifikasi"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/posts\/15809","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/comments?post=15809"}],"version-history":[{"count":1,"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/posts\/15809\/revisions"}],"predecessor-version":[{"id":15811,"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/posts\/15809\/revisions\/15811"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/media\/15810"}],"wp:attachment":[{"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/media?parent=15809"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/categories?post=15809"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ihs.com.tr\/blog\/wp-json\/wp\/v2\/tags?post=15809"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}