Problem 1 Find the key and decrypt the following message whi

Problem 1. Find the key and decrypt the following message, which has been encrypted with the Vigen`ere cipher and an unknown key

MYYWL IRLMT XENHM FRNAL FRNBJ LNCES VFHMP GLYMV IIIOP WVOGK XIAKH WLUML TEXZY TUOTA XUYZY XVJKV ZIUFZ HWXBZ MZHVA BFHBU FRNAL FRNBJ LRHWT TKBXT TKCVZ XUOVH MZIGH GUJKV OZXXZ MIIGN LLJIV KKNHA AVVKV TUYKB GZPXY LZNRJ HDGNU BKSUF HWZXY BEATM NCFKH GXYHM BENKV WLWMV KPNAY HLAAH WMUGJ XUGTA AVGTA BTMVV NIMXZ PVUKL WVXBJ TKYWA HVRVL ECYGJ XZHML TTBBU ZRHWZ VYIEH KJBBW BENAL FRNAL FRNBJ TCMVP XEWXZ PVUKL VFGFP MKYWA HGLXW TICGN ZIUWB TKYLD AFBTC XJNKV GXGTA AVGTA BTUEZ DZFEZ UIITK FRNAL FRNBJ TCEGV PCYWN XRHWD AFWTU TGJEF MYYBY DEIPS XUAXH GUWHT FLHBJ TKYMO XZLNU WVLLA TEXBU ZKIHA AVLLA AVXXW TINFL GKZNY MYYKK XJCKL LKILL KMYTZ TIYLV NIWXA HFOKY XXCHU BEGTA AVGTA BTMFH MYYFH MZWLL WLWTA BFHTU WJNTA BJNBJ L

Find the key and decrypt the following message, which has been encrypted with the Vigenere cipher and an unknown key.

Solution

we can see that the key lenth is 5

so doing frequency anaylsis

key word : TRUTH

   THE DEPARTMENT OFMATHEMATICS WILL ONTINUE TO PROVIDE UNDERGRADUATE AND GRADUATE DEGREE PROGRAMS OF DISTINCTION IN MATHEMATICS AND MATHEMATICS EDUCATION AND PROVIDE STRONG SUPPORT TO THE BROADER UNIVERSITY COMMUNITY BY OFFERING A FULL RANGE OF INTRODUCTORY THROUGH ADVANCED MATHEMATICS COURSES WE ARE DEDICATED TO EXCELLENCE IN TEACHING AND SCHOLARSHIP IN THE MATHEMATICAL SCIENCES WE ARE COMMITTED TO PREPARING GRADUATES WHO HAVE STRONG MATHEMATICAL SKILLS BROAD MATHEMATICAL KNOWLEDGE AND WHO CAN APPLY THEIR KNOWLEDGE AND COMMUNICATE THEIR UNDERSTANDING TOO THERS THE DEPARTMENT