Hmm, I thought Ciphersaber was basically RC4 with a little header. I'll take another look at it.

(later) I see. "level 2" was added as a response to that weakness.

The thing about RC4 was the presence of weak keys. The paper was a proof, but too technical to really understand as a user. I would suppose that one could preprocess the key string or postprocess the permutation (the thing that the passphrase generates) to avoid the weak keys, but nothing like that was stated. If Ciphersaber tracks these kinds of issues, as a slightly higher level than raw RC4 it indeed looks attractive.

—John