Vignere Decryption

This project attempts to decode a given English language vignere encrypted string through frequency analysis. It works best with larger sample texts.

Example

Input: ETGURLXRGAJGMOMTGECGXANUJCCMXBTFKTHRNFZNAHQNVZABBWFKFLXMANUYCGXXUCKFTUIPCDCPVUHCZLIXHJKKFIAIJTZRXGKFQWYAUIEVZRGBXUGDGJLEAFGMGMENPUFXLMAVVPTLXVPTPNIXBIIYEACJCJGVGMGGUDDKQNPPWTTVFEIWEMSTTRNWRANUEMIAMAIDMGXXUCEYIHSYVYYIAIYRVBWBQUKJBXIPBORRXVABTBZJMEGVYCPZIBHKFXKXLPZLTOMTGECGXHREZBTWXUCKFTAEQCDYHLIQGEMJZLZQECNMSOGRZAXXBCSYCWSAJZQRTVRGIYCWGBPTCCMVNVVMCTPVHVMULXHFPGIPEFQEJNMLRPKFPMLRDVEPGVRUVYGVLVPKMPGIJEZNWXV

Output:

key: encrypt

decoded: agedtwentysixvigenerewassenttoromeonadiplomaticmissionitwasherethathebecameacquaintedwiththewritingsofalbertitrithemiusandportaandhisinterestincryptographywasignitedformanyyearscryptographywasnothingmorethanatoolthathelpedhimhisdiplomaticworkbutattheageofthirtyninevigeneredecidedthathehadamassedenoughmoneytobeabletoabandonhiscareerandconcentrateonalifeofstudyitwasonlythenthathebeganresearchintoanewcipher