[DanBC]

Really?

(https://en.wikipedia.org/wiki/Convergent_encryption)

(http://www.hnsearch.com/search#request/all&q=convergent+...)

etc etc.

Do you have a more specific question, because there are people on HN who can answer it.

[adcoelho]

Since the same plaintext produces the same ciphertext with different passwords dosn't it expand the search space for a possible attacker?