ctf-writeups

OK BOOMER

7778866{844444777_7446666633_444777_26622244433668}

Since the flag starts with sun{, we know that:

1. 777 -> s
2. 88 -> u
3. 66 -> n

It reminds me of the telephone keypad, where each keypad maps to multiple characters, and you must repeat to select the correct character. However, the 7 keypad is weird, 777 should be r instead of s. Nevertheless, we can guess the flag out:

• part 1:
  • 8 -> t
  • 44444 -> hi/ih
  • 777 -> s
  • this
• part 2:
  • 7 -> p
  • 44 -> h
  • 66666 -> no/on
  • 33 -> e
  • phone
• part 3:
  • 444 -> i
  • 777 -> s
  • is
• part 4:
  • 2 -> a
  • 66 -> n
  • 222 -> c
  • 444 -> i
  • 33 -> e
  • 66 -> n
  • 8 -> t

Flag: sun{this_phone_is_ancient}.