The most common and most likely answer to this crossword clue is the 11 letter word SHIBBOLETHS
I've seen this crossword clue in Financial Times
S
H
I
B
B
O
L
E
T
H
S
Buddy explains!
The straight part
We know that "the group passwords" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case the group passwords = shibboleths.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 SHIBBOLETHS mean?
SHIBBOLETHS noun- A word, especially seen as a test, to distinguish someone as belonging to a particular nation, class, profession etc.
- A common or longstanding belief, custom, or catchphrase associated with a particular group, especially one with little current meaning or truth.