write up ctf by ariafatah

ariaf.my.id/ctf_aria/cryptography/M_Vigenere.html

soal

Can you decrypt this message?
Decrypt this message using this key “CYLAB”.

hint

  • https://en.wikipedia.org/wiki/Vigen%C3%A8re_cipher

solve

wget https://artifacts.picoctf.net/c/159/cipher.txt

cat cipher.txt
# rgnoDVD{O0NU_WQ3_G1G3O3T3_A1AH3S_f85729e7}

tool

  • https://cyberchef.org/#recipe=Vigen%C3%A8re_Decode(‘CYLAB’)&input=cmdub0RWRHtPME5VX1dRM19HMUczTzNUM19BMUFIM1NfZjg1NzI5ZTd9 alt text 
    cipher = rgnoDVD{O0NU_WQ3_G1G3O3T3_A1AH3S_f85729e7}
KEY = CYLAB
# picoCTF{D0NT_US3_V1G3N3R3_C1PH3R_d85729g7}

flag

picoCTF{D0NT_US3_V1G3N3R3_C1PH3R_d85729g7}