Codemash CTF - 7 - Happy Eyes
Hint
07 - Happy Eyes
Barbara really loves to chat with all friends.
To express joy they use the characters ^^ which represent eyes of a smiling face.
Can you find this happy flag?
Hint: Offset by 2
1xT-Gcm8FV-5cYN-iBc-syHW
Approach
This one is tricky. The offset 2 indicates that there is a tool out there that takes an input. Looking at the text, it contains c, m, 1, and 8, so it may just be a scramble of the text. After playing with a lot of tools online, I found a super-tool that has all sorts of cipher varieties:
After that, another hint came along from the @codemashctf twitter account:
A big dropoff in US submissions of challenge 7 answers… Just find the right tool to get the job done! Are you on the fence? Don't let these Europeans scare you off, they can't win any way.
— CodeMash CTF (@CodeMashCTF) January 4, 2018
The hint was subtle, but the On the fence portion just didn’t fit. A quick search of the ciphers that contain fence, and you find the Rail Fence cipher. I found a tool that included the offset option.
Setting the offset to 2 results in:
cm18-FxVs-T5yc-YHNG-WicB