{"id":4579,"date":"2015-03-27T18:53:04","date_gmt":"2015-03-27T16:53:04","guid":{"rendered":"http:\/\/pimedios.es\/?p=4579"},"modified":"2015-03-27T19:28:11","modified_gmt":"2015-03-27T17:28:11","slug":"criptografia-simetrica","status":"publish","type":"post","link":"http:\/\/pimedios.jesussoto.es\/?p=4579","title":{"rendered":"Criptograf\u00eda sim\u00e9trica"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-4580\" src=\"http:\/\/pimedios.es\/wp-content\/uploads\/2015\/03\/csimetrica-300x160.png\" alt=\"csimetrica\" width=\"300\" height=\"160\" srcset=\"http:\/\/pimedios.jesussoto.es\/wp-content\/uploads\/2015\/03\/csimetrica-300x160.png 300w, http:\/\/pimedios.jesussoto.es\/wp-content\/uploads\/2015\/03\/csimetrica.png 636w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/>Designamos por criptograf\u00eda sim\u00e9trica a los m\u00e9todos criptogr\u00e1ficos en los cuales se usa una misma clave para cifrar y descifrar mensajes.<\/p>\n<p><iframe loading=\"lazy\" src=\"https:\/\/www.youtube.com\/embed\/AJscZy1O8oo\" width=\"560\" height=\"315\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p>Un ejemplo sencillo lo podemos hacer utilizando la simetr\u00eda de una matriz. Supongamos que tenemos una frase:<\/p>\n<blockquote><p>edici\u00f3n 6.2 del carnaval de matem\u00e1ticas en el blog la aventura de la ciencia<\/p><\/blockquote>\n<p>Ahora dispongamos la frase en una matriz cuadrada de orden mayor que el n\u00famero de caracteres a cifrar:<br \/>\n$$\\begin{array}{|c|c|c|c|c|c|c|c|c|} \\hline<br \/>\ne&amp; d&amp; i&amp; c&amp; i&amp; o&amp; n&amp; &amp; 6 \\\\ \\hline<br \/>\n.&amp; 2&amp; &amp; d&amp; e&amp; l&amp; &amp; c&amp; a \\\\ \\hline<br \/>\nr&amp; n&amp; a&amp; v&amp; a&amp; l&amp; &amp; d &amp;e \\\\ \\hline<br \/>\n&amp; m&amp; a&amp; t&amp; e&amp; m&amp; a&amp; t &amp;i\\\\ \\hline<br \/>\nc&amp;a&amp; s&amp; &amp; e&amp; n&amp; &amp; e&amp;l\\\\ \\hline<br \/>\n&amp;\u00a0 b&amp; l&amp; o&amp; g&amp; &amp; l&amp;a&amp;\u00a0 \\\\ \\hline<br \/>\na&amp;v&amp; e&amp; n&amp; t&amp; u&amp;r&amp;a &amp;\\\\ \\hline<br \/>\nd&amp;e&amp; &amp; l&amp; a&amp; &amp;c&amp;i&amp;e\\\\ \\hline<br \/>\nn&amp;c&amp; i&amp; a&amp; &amp; &amp;&amp;&amp;\\\\ \\hline<br \/>\n\\end{array}$$<\/p>\n<p>Ahora trasponemos la matriz:<\/p>\n<p>$$\\begin{array}{|c|c|c|c|c|c|c|c|c|}\\hline<br \/>\ne &amp;. &amp;r &amp;\u00a0 &amp;c &amp;\u00a0 &amp;a &amp;d &amp;n\\\\ \\hline<br \/>\nd &amp;2 &amp;n &amp;m &amp;a &amp;b &amp;v &amp; e&amp;c\\\\ \\hline<br \/>\ni&amp;&amp;a&amp;a&amp;s&amp;l&amp;e&amp;&amp;i\\\\ \\hline<br \/>\nc&amp;d&amp;v&amp;t&amp; &amp;o&amp;n&amp;l&amp;a\\\\ \\hline<br \/>\ni&amp;e&amp;a&amp;e&amp;e&amp;g&amp;t&amp;a&amp;\\\\ \\hline<br \/>\no&amp;l&amp;l&amp;m&amp;n&amp; &amp;u&amp;&amp;\\\\ \\hline<br \/>\nn&amp;&amp;&amp;a&amp;&amp;l&amp;r&amp;c&amp;\\\\ \\hline<br \/>\n&amp;c&amp;d&amp;t&amp;e&amp;a&amp;a&amp;i&amp;\\\\ \\hline<br \/>\n6&amp;a&amp;e&amp;i&amp;l&amp; &amp; &amp;e&amp;\\\\ \\hline \\end{array}$$<br \/>\nLo que nos da la frase<\/p>\n<blockquote><p>e.r c adnd2nmabveci aasle icdvt onlaieaeegta ollmn u\u00a0 n\u00a0 a lrc\u00a0 cdteaai 6aeil\u00a0 e<\/p><\/blockquote>\n<p>Como vemos el proceso es muy simple y la clave <strong>Trasponer matriz 9&#215;9<\/strong> es la misma para el que cifrar y el que descifra. Pero se puede complicar m\u00e1s, ejemplos tenemos en <a href=\"http:\/\/es.wikipedia.org\/wiki\/Data_Encryption_Standard\" target=\"_blank\">DES<\/a> o en <a href=\"http:\/\/es.wikipedia.org\/wiki\/Advanced_Encryption_Standard\" target=\"_blank\">AES<\/a>.<\/p>\n<blockquote><p>Con esta entrada participamos en la Edici\u00f3n 6.2 del Carnaval de Matem\u00e1ticas cuyo anfitri\u00f3n, en este mes, es La Aventura de la Ciencia,.<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>Designamos por criptograf\u00eda sim\u00e9trica a los m\u00e9todos criptogr\u00e1ficos en los cuales se usa una misma clave para cifrar y descifrar mensajes. <\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5,8],"tags":[89,634,478],"class_list":["post-4579","post","type-post","status-publish","format-standard","hentry","category-general","category-ocio","tag-criptografia","tag-simetrica","tag-ucam-knoledge-pills","entry"],"_links":{"self":[{"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=\/wp\/v2\/posts\/4579","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4579"}],"version-history":[{"count":11,"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=\/wp\/v2\/posts\/4579\/revisions"}],"predecessor-version":[{"id":4591,"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=\/wp\/v2\/posts\/4579\/revisions\/4591"}],"wp:attachment":[{"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4579"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4579"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/pimedios.jesussoto.es\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4579"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}