{"id":3857,"date":"2022-02-20T12:41:29","date_gmt":"2022-02-20T11:41:29","guid":{"rendered":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/?p=3857"},"modified":"2022-02-21T16:11:15","modified_gmt":"2022-02-21T15:11:15","slug":"le-code-de-jules-cesar","status":"publish","type":"post","link":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/2022\/02\/20\/le-code-de-jules-cesar\/","title":{"rendered":"Le code de Jules C\u00e9sar"},"content":{"rendered":"
\n

Pour envoyer des messages cod\u00e9s \u00e0 ses lieutenants, Jules C\u00e9sar invente en 58 avant J\u00e9sus-Christ son code.<\/strong><\/p>\n\n\n\n

Il consiste \u00e0 prendre l’alphabet et \u00e0 d\u00e9caler chaque lettre de 3 trois rangs. Ainsi un A \u00e9tait en r\u00e9alit\u00e9 un D, un B \u00e9tait un E… <\/p>\n\n\n\n

clair : ABCDEFGHIJKLMNOPQRSTUVWXYZ crypt\u00e9 : DEFGHIJKLMNOPQRSTUVWXYZABC <\/p>\n\n\n\n

Seulement, si C\u00e9sar utilisait toujours le m\u00eame code, il \u00e9tait facile \u00e0 d\u00e9chiffrer. Alors, au lieu de d\u00e9caler de trois rangs, on d\u00e9calait chaque lettre de 4, 5 ou 20 rangs.<\/p>\n\n\n\n

On pouvait aussi utiliser un mot-cl\u00e9, par exemple placer le mot MATHS au d\u00e9but de l’alphabet, un A \u00e9quivaudrait \u00e0 un M, un B \u00e0 un A et \u00e0 la suite du mot-cl\u00e9, le reste de l’alphabet dans l’ordre.<\/p>\n\n\n\n

clair : ABCDEFGHIJKLMNOPQRSTUVWXYZ crypt\u00e9 : MATHS<\/strong>BCDEFGIJKLNOPQRUVWXYZ<\/p>\n\n\n\n

sources :<\/strong> – Wikip\u00e9dia, l’encyclop\u00e9die libre (wikipedia.org)<\/a> – OKAPI num\u00e9ro 1101 : Le myst\u00e8re des codes secrets -Le monde des codes secrets de Philippe Nessmann<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"

Pour envoyer des messages cod\u00e9s \u00e0 ses lieutenants, Jules C\u00e9sar invente en 58 avant J\u00e9sus-Christ sonEn savoir plus…<\/i><\/a><\/p>\n","protected":false},"author":7,"featured_media":3981,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[10],"tags":[316,317,313,314,11],"authors":[{"term_id":55,"user_id":7,"is_guest":0,"slug":"louann","display_name":"louann"}],"_links":{"self":[{"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/posts\/3857"}],"collection":[{"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/comments?post=3857"}],"version-history":[{"count":8,"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/posts\/3857\/revisions"}],"predecessor-version":[{"id":4080,"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/posts\/3857\/revisions\/4080"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/media\/3981"}],"wp:attachment":[{"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/media?parent=3857"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/categories?post=3857"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.ac-nancy-metz.fr\/laptitesource\/wp-json\/wp\/v2\/tags?post=3857"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}