Perl flavor, 109 [cracked]
The previous submission turned out easier than I intended. This one should be a little more challenging, though the short version is still very much brute-forcible.
^([^,]+),(?!\1)([^,]{2,}),(?!\1|\2+,)([^,]{2,}),(?!\1|(?:\2+|\3+),)([^,]{2,}),(?=.\2+$)(?=.\3+$)(?=.\4+$)\1+$
And a longer version, not part of the challenge:
^([^,]+),(?!\1)([^,]{2,}),(?!\1|\2+,)([^,]{2,}),(?!\1|(?:\2+|\3+),)([^,]{2,}),(?!\1|(?:\2+|\3+|\4+),)([^,]{2,}),(?!\1|(?:\2+|\3+|\4+|\5+),)([^,]{2,}),(?!\1|(?:\2+|\3+|\4+|\5+|\6+),)([^,]{2,}),(?!\1|(?:\2+|\3+|\4+|\5+|\6+|\7+),)([^,]{2,}),(?=.\2+$)(?=.\3+$)(?=.\4+$)(?=.\5+$)(?=.\6+$)(?=.\7+$)(?=.\8+$)\1+$
EDIT: The above version turned out too simple as well. Here's a final attempt to make this more challenging.
Perl flavor, 121 [cracked]
Short version:
^([^,]+),(?!\1)([^,]{2,}),(?=\2)(?!\1|\2+,)([^,]{2,}),(?=\3)(?!\1|(?:\2+|\3+),)([^,]{2,}),(?=.\2+$)(?=.\3+$)(?=.\4+$)\1+$
Long version:
^([^,]+),(?!\1)([^,]{2,}),(?=\2)(?!\1|\2+,)([^,]{2,}),(?=\3)(?!\1|(?:\2+|\3+),)([^,]{2,}),(?=\4)(?!\1|(?:\2+|\3+|\4+),)([^,]{2,}),(?=\5)(?!\1|(?:\2+|\3+|\4+|\5+),)([^,]{2,}),(?=\6)(?!\1|(?:\2+|\3+|\4+|\5+|\6+),)([^,]{2,}),(?=\7)(?!\1|(?:\2+|\3+|\4+|\5+|\6+|\7+),)([^,]{2,}),(?=.\2+$)(?=.\3+$)(?=.\4+$)(?=.\5+$)(?=.\6+$)(?=.\7+$)(?=.\8+$)\1+$
