The most common and most likely answer to this crossword clue is the 12 letter word CRYPTOGRAPHY
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More clues leading to the result CRYPTOGRAPHY
Buddy explains!
The straight part
We know that "The characters in this have something to hide" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case the characters in this have something to hide = cryptography.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does CRYPTOGRAPHY mean?
CRYPTOGRAPHY noun- The discipline concerned with communication security (eg, confidentiality of messages, integrity of messages, sender authentication, non-repudiation of messages, and many other related issues), regardless of the used medium such as pencil and paper or computers.