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Is sharing you password length wise? Knowing the # of chars you have reduced the number of iterations needed to complete a brute force attack.

255! vs 255! / (255 - 30)!

My math could be off though, i haven't work with factorials since i was in the university

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I don't think you want a factorial involved.

With unknown size, cracking 30 characters takes time proportional to n^30 + n^29 + n^28 etc.

Cracking just 30 is proportional to n^30.

The difference is negligible. A percent or two.

My bad, I was thinking in permutations but those does not allow repeated entries. It make sense now, like you said the difference is negligible.

It's a trick. OP's password is actually 29 chars long, but the attacker will now start at 30 characters, and never brute force the actual password. Nicely played.

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