HH - Crypto
Crpyto Challenge Write-ups
Green Flags 🟢
Description: Flag Frenzy In a sea of encrypted flags, your mission is to unravel the chaos and reveal the hidden truth.
Flag_Format: CM{abcd_abcdefgh}
NATO’s Flaghoist communication was used here. I used the Navy Signals Code to decode the flags.
Do Check out this NATO Codes for viewing the other methods of signals and codes used by NATO. A few re-appear in other CTF’s as well.
Flag:
CM{nato_signals}
I can’t see it
Description: In the land of secrets, where the ordinary becomes extraordinary, there’s a riddle that loves to play hide-and-seek. It’s hiding in plain sight, yet elusive to the eye. Venture into the realm where invisible ink holds the clues, and remember
We are given text in braille. I used dcode braille to decode
Given Text: ⠉⠍⠸⠣⠹⠼⠁⠼⠑_⠃⠗⠼⠙⠼⠁⠇⠇⠼⠉_⠼⠁⠎_⠼⠙⠼⠉⠁⠇⠸⠜
Flag: CM{TH15_BR41LL3_1S_43AL}
Digital Black Hole
Description: Imagine a digital black hole where secrets vanish into thin air. We’ve cast a cryptic message into this void, one that only the most adept machines can decipher
Another easy question, Just had 3 binary encoding stacked + base62 encoding.
Dear Trithemius
Description: The encryption method used in this cipher is a variation of the Caesar cipher, but with a twist. Each letter in the plaintext is shifted by a different amount depending on its position in the string. Non-alphabetic characters remain unchanged. To decrypt, reverse this shifting process.
We have a simple encryption here. It is implementing a variation of caesar cipher by shifting each character differently. Wrote a simple decryption code using the existing functions and got the flag.
Also the given code was given a .go extension but it was python code.
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love_letter = "LPXH_Z_AZRDSQZWJI"
def to_my_honey(owo):
return ord(owo) - 0x41
def from_your_lover(uwu):
return chr(uwu % 26 + 0x41)
def decrypt(love_letter):
billet_doux = ''
for heart in range(len(love_letter)):
letters = love_letter[heart]
if not letters.isalpha():
owo = letters
else:
uwu = to_my_honey(letters)
owo = from_your_lover(uwu - heart)
billet_doux += owo
return billet_doux
Flag: CM{LOVE_U_TRITHEMIUS}
My Secret X ‘V’ My Secret Y
Description: A message from the cheeky code gremlins: Our secrets are hidden in plain sight, like a magician’s trick. Your task? Play peekaboo with bytes to reveal what’s concealed. Remember, it’s not about where they’re hiding but who’s hiding!”
Hide: 6866507f43181e1874531b79741f59187448791f517256 & Seek: ??????????????
It was a simple XOR encryption. Used cyberchef to bruteforce the key.
Key = 2b: CM{Th353_x0R_4r3_cR4zY}