Tags: morse bacon crypto
Rating: 5.0
# Twice as secret, Right?
## Description
> Evelyn was snooping on some parking lot RF chatter when she noticed an interesting signal on a weird frequency. The provided link has a sample of the intercepted signal after it was cleaned up:
>
> https://cdn.discordapp.com/attachments/676467674783547432/695740859316174848/mystery_signal.wav
>
> Note: This flag does not follow the normal format
## Solution
Listening to the file we recognize morse code. So we use a Morse code decoder from sound file: https://morsecode.world/international/decoder/audio-decoder-adaptive.html
From there (with a little extrapolation from our part) we get the following string:
`BABAAAABAAABABAABABAAABBBAAAAABAABBAABAABAABAABBABABABBAABAAAABAABAABAAAAAAABBAAABBABBAABAAABBBAABAABAAAAAAABBAAAAABABBABABAAAABAABAAAAAABAAAABAABABABABBBAAABAAAAABABAABAABAAAABBAAAABBABAABAAABBBAABAAABABBBAABAABBABAAABAABBABABABBAABAAAABBBAABAABAAAAAABAABAAABABBABABBABABBAABAABAAABBBAABAAABABBAABAABAAABBAAABAAAAAAABBAAABAAAABBBAAAAABAAABBAABAABBABAAAABAABAAAAABBAABAAABABAABAAABAABBAABAABAAAAAABAAAAABBBAAABABBABABBABABBAAABBABBAABAAABBBAABAABAAAABABAAABAAABAAABAABAAAAAAAABABAABABAABAAABAAABAABABABBABBAAAAABBAAAAAAABAABBAABBAAABBBBAABABAABAAABBBAABAAAABABABABAAAAAAAABBAABAAABAAABAAAAABAABBAAABABAABAAABABBAAABABBABABABBAABAAABBABABBAAAABAAABBAAAABAAAABAAAAABBBAAABBAABAABBABAAABAAAAAAABABAABABABAABAAABBBAABAAAABABAAABAAAABAABBABABBAABAABAAABBBAABAABAAABAABAAAAABABAAAAAAAAABABBBBABBAAABABAAAAABAAAAABABBAABAABAAAABAAAB`
After trying binary decoding with no result, we recognised a Bacon cipher, coded on 5 characters. We could have calculated the string length to give us a clue. We used https://www.dcode.fr/bacon-cipher to decrypt the message, this gives
`WELL HAVE TO MEET ANOTHER DAY WERE EXPECTING THEM TO COME HERE SOON THE MESSAGE HAS TO BE DELIVERED SOON OTHERWISE ALL IS FOR NAUGHT THE FLAG IS AUCTF SOMEONE NEEDS TO CALL THE FCC ON THESE CRAZY FARMERS`
Flag: `AUCTF SOMEONE NEEDS TO CALL THE FCC ON THESE CRAZY FARMERS`
