On 6 March, Yi Lee sent over the NIST mailing list an announcement of their submitted paper that found a flaw in the original security proof for Dilithium. In their manuscript, they fix the proof on paper, and they also verified whole proof using EasyCrypt. URL: http://ia.cr/2023/246
In Section 3.2, paragraph "The ‘Program once’ game hop", they bound the distance between $\mathcal{A}^\textsf{Prog}$ and $\mathcal{A}^\textsf{Trans}$, where $\textsf{Prog}$ is an oracle that programs $H$ for all inputs $(w, m)$ that were queried in the signature generation algorithm, and $\textsf{Trans}$ is an oracle that only programs $H$ for the $(w, m)$ input that was used in generating the accepted signature. This game hop adds a bias to $H$, biasing it towards $(w, m)$ tuples that correspond to accepting transcripts (as the only $(w,m)$ tuples programmed into $H$ are from accepted transcripts).
In the paper, it is mentioned that it is hard for $\mathcal{A}$ to notice this change, "because $w$ is chosen with high entropy and not revealed to $\mathcal{A}$.
Conversely, leaking rejected $w$s breaks the security reduction.
But now I am wondering:
Should the rejected $w$s considered to be secret? Or in other words, does leaking the rejected $w$s always break the zero knowledgeness property of Dilithium?
Or is there reason to believe that another security reduction could be constructed in a way that allows for the leaking of the rejected $w$s?