Frequency had 30 points in APAIUT-CERT CTF .
the cipher was :
QV KZGXBWOZIXPG, I KIMAIZ KQXPMZ, ITAW SVWEV IA KIMAIZ'A KQXPMZ, BPM APQNB KQXPMZ, KIMAIZ'A KWLM WZ KIMAIZ APQNB,
QA WVM WN BPM AQUXTMAB IVL UWAB EQLMTG SVWEV MVKZGXBQWV BMKPVQYCMA. QB QA I BGXM WN ACJABQBCBQWV KQXPMZ QV EPQKP MIKP TMBBMZ QV BPM XTIQVBMFB QA ZMXTIKML JG I TMBBMZ AWUM NQFML VCUJMZ WN XWAQBQWVA LWEV BPM ITXPIJMB. NWZ MFIUXTM, EQBP I TMNB APQNB WN 3, L EWCTL JM ZMXTIKML JG I, M EWCTL JMKWUM J, IVL AW WV. BPM UMBPWL QA VIUML INBMZ RCTQCA KIMAIZ, EPW CAML QB QV PQA XZQDIBM KWZZMAXWVLMVKM. NTIO: BP1AEIAMIAG
without any analyzing we can understand from name of challange it’s something between Vignere , Caesar , Autokey Autokey is substitution cipher wich had a key for changing place of each Character and also we can solve it as Cryptogram and Puzzle with Code breakers so i used SCB Solver or you can use this online script named quipquip at http://www.quipqiup.com/ for this Cipher
secret key: IJKLMNOPQRSTUVWXYZABCDEFGH (means the changes of alphabet order in english)
decoded message:
in cryptography, a caesar cipher, also known as caesar’s cipher, the shift cipher, caesar’s code or caesar shift, is one of the simplest and most widely known encryption techniques. it is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. for example, with a left shift of 3, d would be replaced by a, e would become b, and so on. the method is named after julius caesar, who used it in his private correspondence. flag: th1swaseasy
at the end of decoded cipher you can find the flag :
1
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30 points ;)