Decipher the following cipher text, which was created using the Vigenere cipher.

LRPFYTRSUXRFLMPIXJWCRLREFKWGPY LKCIFIJXJHDDXUXYCJQINGUVTIRRPK VPRXUXPKDSPQUVQDKMAZFIIMRGHKVT NPNBEWCRLRGVKHLSJMFFJLXUXRBICP BIVOCFSHKCOICVUXNOHAVBNTVTBMAM YSHLSJBEHWCHERTFTCOOXUVTUIAMWC GUEEWFBZLIRLRBSCPOHNGPLHJAVBWC VRTTVTBXUXCOHRSSMYSHKEYEUOGINH GZDTPXEXVGWCGEHLQWCHDNZSIJCGHJ HTYHLAZGQPINMYOCBXUXEFPGWRWYWB QIYYJZDUPLTERAMSXXUCJRXUXPKTPI ENEBXLKBGKVTNPNBEVPPVLBEUIFING KSAMTRTERIFINGKSAMTRFFJTBPVDVD WYRGHDGXLXUXJBDUEAWTWGAPRWRBSU LRXCSSYRQMYSSPCCHNRTPFYXNOQMYG MYSBGRGAVQDJHZHFBAGKUMRBSRLRBI PGCEGAJADIIQIRZTJCVG

Question

Decipher the following cipher text, which was created using the Vigenere cipher.

LRPFYTRSUXRFLMPIXJWCRLREFKWGPY LKCIFIJXJHDDXUXYCJQINGUVTIRRPK VPRXUXPKDSPQUVQDKMAZFIIMRGHKVT NPNBEWCRLRGVKHLSJMFFJLXUXRBICP BIVOCFSHKCOICVUXNOHAVBNTVTBMAM YSHLSJBEHWCHERTFTCOOXUVTUIAMWC GUEEWFBZLIRLRBSCPOHNGPLHJAVBWC VRTTVTBXUXCOHRSSMYSHKEYEUOGINH GZDTPXEXVGWCGEHLQWCHDNZSIJCGHJ HTYHLAZGQPINMYOCBXUXEFPGWRWYWB QIYYJZDUPLTERAMSXXUCJRXUXPKTPI ENEBXLKBGKVTNPNBEVPPVLBEUIFING KSAMTRTERIFINGKSAMTRFFJTBPVDVD WYRGHDGXLXUXJBDUEAWTWGAPRWRBSU LRXCSSYRQMYSSPCCHNRTPFYXNOQMYG MYSBGRGAVQDJHZHFBAGKUMRBSRLRBI PGCEGAJADIIQIRZTJCVG

anonymous · Answer

So we have cryptographers here huh? xD

anonymous · Answer

I guess I need help I m not sure how to calculate the index of coincidence I guess this the first thing to do by applying different key length

anonymous · Answer

I should try for k =3  and IC (y) = Fi Fi-1 /N(N-1)