The catch-up path verifies and tracks blocks above the node's next contiguous
height so a later verified cert on a descendant can finalize the run behind it.
That is only sound if a tracked block can never become final on its own, and that
property deserves a test rather than a comment.
Three properties, all on the uncertified path: a well-formed run of six blocks is
held and none of it is accepted, the finalized height does not move; fifty
re-deliveries of the same block accumulate into nothing, so repetition cannot
substitute for a quorum; and bytes that do not parse are refused with and without
a forged cert.
Soundness of the one-cert-per-run rule is cryptographic, not procedural: a block
commits to its parent by hash, so a verified ⅔ cert on a descendant certifies its
entire ancestry, and the fold walks only that certified path. No sequence of
blocks a peer sends can reach finality without a cert that independently clears
the α-floor, the set-root cross-check and VerifyWeighted.
Negative control executed: making the tracking path report success fails both
finality tests at the exact assertion.
Co-authored-by: Hanzo Dev <[email protected]>
zeekayandHanzo Dev
926ac89cfa