{"id":1558,"date":"2024-11-25T15:16:02","date_gmt":"2024-11-25T14:16:02","guid":{"rendered":"https:\/\/www.scouts-europe.org\/scoutorama\/?p=1558"},"modified":"2025-02-11T14:56:42","modified_gmt":"2025-02-11T13:56:42","slug":"le-code-jules-cesar","status":"publish","type":"post","link":"https:\/\/www.scouts-europe.org\/scoutorama\/le-code-jules-cesar\/","title":{"rendered":"Le code Jules C\u00e9sar"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-post\" data-elementor-id=\"1558\" class=\"elementor elementor-1558\">\n\t\t\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-8041808 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"8041808\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-7caf085\" data-id=\"7caf085\" data-element_type=\"column\" data-e-type=\"column\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-4eb47f7 elementor-widget elementor-widget-heading\" data-id=\"4eb47f7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Le code Jules C\u00e9sar<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-721ab5e elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"721ab5e\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-d46eb97\" data-id=\"d46eb97\" data-element_type=\"column\" data-e-type=\"column\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-c306bc5 elementor-widget elementor-widget-spacer\" data-id=\"c306bc5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4f4c36d elementor-widget elementor-widget-text-editor\" data-id=\"4f4c36d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div id=\"chapo_article\"><div id=\"chapo_article li\"><p>Facile \u00e0 coder, long \u00e0 d\u00e9coder&#8230;<\/p><\/div><\/div>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-d924bf9 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"d924bf9\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-1730870\" data-id=\"1730870\" data-element_type=\"column\" data-e-type=\"column\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-dc64d2e elementor-widget elementor-widget-heading\" data-id=\"dc64d2e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Description<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1f26f0e elementor-widget elementor-widget-text-editor\" data-id=\"1f26f0e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Ce code consiste \u00e0 faire repr\u00e9senter une lettre par une autre. Par exemple A par E. Ainsi B devient F, C devient G etc\u2026 L\u2019ensemble de l\u2019alphabet est d\u00e9cal\u00e9 de quatre lettres. On appelle souvent cette sorte de substitution un \u00ab\u00a0Jules C\u00e9sar\u00a0\u00bb parce que, s\u2019il n\u2019en est pas l\u2019inventeur, il en fit un abondant usage.<\/p><p>Rien n\u2019est plus facile que de d\u00e9chiffrer un tel message s\u2019il tombe entre tes mains. Si le texte est court, il suffit de d\u00e9cliner lettre par lettre jusqu\u2019\u00e0 ce que tu aies un texte qui se tienne.<\/p><p>Exemple\u00a0:<\/p><p>IBMXOXMIRFBABDOXKAJBOBKBMLRQOXMXPPBOSFOMLROJCNPYN\u2026<\/p><p>LEPARAPLUIEDEGRANDMERENEPOURRAPASSERVIRPOUR\u2026<\/p><p>Dans ce cas, B = E.<\/p><p>Si le texte est un peu long, borne-toi \u00e0 rep\u00e9rer la lettre la plus fr\u00e9quente. Ce sera infailliblement en fran\u00e7ais la lettre E qui se trouve environ 17 fois sur 100 dans un texte quelconque. Si tu rencontres donc une forte pr\u00e9dominance de K ou de W, tu en conclueras que l\u2019alphabet a \u00e9t\u00e9 d\u00e9cal\u00e9 de six ou de dix-huit rangs.<\/p><p>Quel int\u00e9r\u00eat y a-t-il, diras-tu, \u00e0 indiquer un syst\u00e8me aussi facile \u00e0 d\u00e9crypter et donc peu efficace ?<\/p><p>D\u2019abord, les gens ne sont pas si malins que \u00e7a, et si tu utilises un Jules C\u00e9sar en prenant la pr\u00e9caution d\u2019\u00e9crire ton message \u00e0 l\u2019envers, beaucoup \u2014 et des plus astucieux \u2014 se d\u00e9courageront vite. Mais surtout ce proc\u00e9d\u00e9 m\u00e8ne \u00e0 d\u2019autres syst\u00e8mes infiniment moins p\u00e9n\u00e9trables et qui sont r\u00e9guli\u00e8rement utilis\u00e9s de nos jours dans les correspondances officielles et secr\u00e8tes.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-d729aa6 elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"d729aa6\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-51648cf\" data-id=\"51648cf\" data-element_type=\"column\" data-e-type=\"column\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-5cac87b elementor-widget elementor-widget-heading\" data-id=\"5cac87b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Le cryptographe<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-26af085 elementor-widget elementor-widget-text-editor\" data-id=\"26af085\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Tu peux fabriquer une Roue pour d\u00e9chiffrer les cryptographes.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-14e71e7 elementor-widget elementor-widget-image\" data-id=\"14e71e7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"154\" height=\"154\" src=\"https:\/\/www.scouts-europe.org\/scoutorama\/wp-content\/uploads\/sites\/99\/2024\/11\/code-49d36.gif\" class=\"attachment-large size-large wp-image-1560\" alt=\"code 49d36\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"elementor-section elementor-top-section elementor-element elementor-element-daa079c elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-id=\"daa079c\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-6611e74\" data-id=\"6611e74\" data-element_type=\"column\" data-e-type=\"column\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-0b2d8aa elementor-widget elementor-widget-text-editor\" data-id=\"0b2d8aa\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>D\u00e9coupe d\u2019abord deux cercles dans du bristol, un l\u00e9g\u00e8rement plus petit que l\u2019autre.<br \/>Avec un rapporteur, divise chaque cercle en 26 sections de 13,8 degr\u00e9s.<br \/>\u00c9cris une lettre de l\u2019alphabet dans chaque division de chaque roue.<br \/>Attache ensuite les deux roues en leur centre au moyen d\u2019une attache parisienne de fa\u00e7on \u00e0 ce que tu puisses les faire tourner s\u00e9par\u00e9ment.<\/p><p>D\u00e9sormais, si tu veux transcrire un cryptographe o\u00f9 l\u2019alphabet a gliss\u00e9 de 3 rangs, il te suffit de mettre le A et le C en face l\u2019un de l\u2019autre et tu pourras traduire le message\u00a0!<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Ce code consiste \u00e0 faire repr\u00e9senter une lettre par une autre. Par exemple A par E. Ainsi B devient F, C devient G etc\u2026 L\u2019ensemble de l\u2019alphabet est d\u00e9cal\u00e9 de quatre lettres. On appelle souvent cette sorte de substitution un \u00ab\u00a0Jules C\u00e9sar\u00a0\u00bb parce que, s\u2019il n\u2019en est pas l\u2019inventeur, il en fit un abondant usage.<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","_seopress_titles_title":"","_seopress_titles_desc":"","_seopress_robots_index":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[64,24],"tags":[],"class_list":["post-1558","post","type-post","status-publish","format-standard","hentry","category-codes-secrets","category-transmissions"],"_links":{"self":[{"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/posts\/1558","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/comments?post=1558"}],"version-history":[{"count":10,"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/posts\/1558\/revisions"}],"predecessor-version":[{"id":6617,"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/posts\/1558\/revisions\/6617"}],"wp:attachment":[{"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/media?parent=1558"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/categories?post=1558"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.scouts-europe.org\/scoutorama\/wp-json\/wp\/v2\/tags?post=1558"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}