chore(aztec-nr): clarify in comments that nullifier computation does …

…not need to include siloed note-hash for protocol security (#2667)

Resolves #2666

noir-projects/aztec-nr/aztec/src/note/utils.nr

@@ -74,6 +74,14 @@ pub fn compute_note_hash_for_consumption<Note, N>(note: Note) -> Field where Not
         // contract address and then nonce. This hash will match the existing leaf in the private
         // data tree, so the kernel can just perform a membership check directly on this hash/leaf.
         compute_unique_siloed_note_hash(note)
+        // IMPORTANT NOTE ON REDUNDANT SILOING BY CONTRACT ADDRESS: The note hash computed above is
+        // "siloed" by contract address. When a note hash is computed solely for the purpose of
+        // nullification, it is not strictly necessary to silo the note hash before computing
+        // its nullifier. In other words, it is NOT NECESSARY for protocol security that a nullifier
+        // be computed from a siloed note hash. After all, persistable note hashes and nullifiers are
+        // siloed by the kernel circuit. That being said, the siloed note hash computed above CAN be
+        // used for nullifier computation, and this achieves the (arguably unnecessary) property that
+        // nullifiers are computed from a note hash's fully-computed private data tree leaf.
     }
 }