Runbook: A3b (key backup) completed by operator, 2026-07-14

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

ATTESTATION-RUNBOOK.md

@@ -44,7 +44,7 @@ Agent Appendix at the end. Every step ends in a mechanical check.
 | pacta | github.com/saymrwulf/proof-aware-crypto-tooling-agent | `3d81d53` (change-frozen during paper processing) |
 | Forgejo mirrors | `https://zkdefi.org/saymrwulf/<repo>.git` (anonymously readable) | pull-synced by server cron nightly 03:00 UTC (`/home/admin/cloud/bin/reconcile-mirrors.py`, log `.reconcile.log`); verify per step A5 |
 | log public key | `lean-transparency-log/provider.ed25519.pub` (PEM) | fingerprint `874c8a00…a56a` in `log-metadata.json` |
-| log PRIVATE key | **RESOLVED 2026-07-12**: laptop-side, mode 0600, inside a gitignored state dir of the pacta working tree (exact path in operator-private notes, deliberately not in this public file); public half byte-matches `provider.ed25519.pub`. NOT on the droplet. **No second copy exists** — see step A3b | A3 done; A3b (backup) open |
+| log PRIVATE key | **RESOLVED 2026-07-12**: laptop-side, mode 0600, inside a gitignored state dir of the pacta working tree (exact path in operator-private notes, deliberately not in this public file); public half byte-matches `provider.ed25519.pub`. NOT on the droplet. **No second copy exists** — see step A3b | A3 done; A3b done (operator, 2026-07-14) |
 | producer driver | **RESOLVED 2026-07-12**: it exists and is committed — pacta's `provider/` CLI (`python3 -m pacta_provider`: `check` → signed attestation; `log-append` → leaf + signed STH + receipt; `log-publish` → public face). Heads are signed with `signing_backend: verified-dalek-serial` (the dogfooded verified signer), `self_inclusion: verified`. Only the per-run orchestration was session work | see step A4 (rehearsal, not reconstruction) |
 | server deployment | private repo `PersonalCloudServer` (github, `master`) — since `a186bac` includes the ltl vhost/service/reconstruct.py, md5-verified == droplet | see its `DEPLOY.md` § "The LTL service" |
 
@@ -115,7 +115,9 @@ throwaway copy is then DELETED (its head was signed with the real key
 over a rehearsal tree — it must never be published or retained; if
 retention is wanted for study, rehearse with a throwaway KEY instead).
 
-### A3b. Back up the signing key (opened 2026-07-12 — the key has NO second copy)
+### A3b. Back up the signing key — **DONE (operator, confirmed 2026-07-14)**
+Completed by the operator; the procedure below is retained as the
+reference for future key-backup refreshes.
 The laptop file is the only copy in existence; a disk failure would
 freeze the log at its current size forever (still verifiable, never
 extendable). Operator-only: create an ENCRYPTED backup (e.g.
@@ -215,6 +217,12 @@ naming. **Check:** SD hashes match the repo files.
   specializations; fidelity = pinned-family testing, extensional
   equality false one-sided; Theorem-3 pinned-pair side condition;
   §10(i)/(v) phrasings) — paper repo, its own commit.
+- Publish the accumulator blog post: source parked at
+  `docs/optimistic-accountability.md` (this repo) — condense to the
+  blog's voice, END WITH A LINK TO THE LIVE LEAF (that is why it
+  waited), operator reviews, then one .md into PersonalCloudServer
+  `blog/posts/`, `build-blog.py`, rsync per its DEPLOY.md. Closes the
+  "one post per public repo" gap for this repo.
 - One-line note in this file: date, leaf hash, head root. Commit.
 
 ---

docs/optimistic-accountability.md

@@ -0,0 +1,130 @@
+# Optimistic by construction: what the LTL holds, and what it shares with rollups
+
+Status: essay / parked blog-post source. Per the operator's decision,
+the blog version publishes only AFTER entry 13 is live (runbook B7),
+when the closing claim — "the log carries kernel-checked proofs of its
+own machinery" — becomes literally true and the post can end with a
+link to a live leaf the reader can verify in one command.
+
+---
+
+## Part I — What is actually inside the Merkle tree
+
+A persistent misreading of transparency logs is that they "contain the
+proofs." The LTL's tree contains none of the Lean mathematics. Each
+leaf is (the 32-byte hash of) a **verification-event record**: a
+signed attestation stating that the provider, at a given time, ran the
+proof checks on a named subject repository at an exact commit, with an
+exact toolchain, and observed a specific result — every certificate
+verified, each with an exactly-listed axiom cone. The records are
+published beside the tree (`entries/`); the proofs themselves live one
+hop further away, in the subject git repositories the records pin.
+
+So a leaf is a statement *about the operator's action* — "I verified
+X" — and on its face that sounds like "trust me." The design's whole
+point is the refinement that removes the trust: **the claim names its
+own evidence.** Because the leaf pins commit hash and toolchain,
+anyone can replay the verification and check the operator's statement.
+The log converts
+
+> "I guarantee I verified the proofs (which live elsewhere)"
+
+into
+
+> "I claim this, permanently and publicly, with enough detail that
+> anyone can catch me lying — and I can never unsay it, edit it, or
+> show a different history to someone else."
+
+Three layers, three distinct guarantees, and most confusion comes from
+expecting one layer to do another's job:
+
+| layer | guarantees | does NOT guarantee |
+|---|---|---|
+| Lean kernel (inside the subject repos) | the mathematics of the attested proofs is true, given the declared axioms | anything about what the operator later claims |
+| replay pin (leaf content) | the operator's claim is CHECKABLE — re-run the pinned commit and compare | that anyone has actually re-run it |
+| Merkle accumulator + signed heads | inclusion (Thms 1–2), append-only history (Thm 3), equivocation evidence (Prop 1): claims cannot be altered, hidden, or forked without producing cryptographic evidence | that any claim is TRUE — the ledger notarizes, it does not referee |
+
+The notary metaphor is exact: a notary does not check that your
+contract is wise; the notary makes it impossible to later dispute
+*what was stamped and when*, and the bound ledger makes tampering
+evident. The LTL is a notary whose every stamped page happens to carry
+instructions for independently re-checking the page's claim.
+
+## Part II — The optimistic-rollup resemblance (it is not a metaphor)
+
+Optimistic rollups rest on one bet: *claims are cheap to make and
+expensive to get away with*. A sequencer posts state roots without
+proof; safety comes from anyone's ability to produce a fraud proof
+from public data, and from punishment when they do. The LTL — like its
+direct ancestor, Certificate Transparency (RFC 9162) — is built on the
+same bet: record everything append-only, and make misbehavior generate
+publicly verifiable, transferable evidence.
+
+The fraud-proof analogue exists in the LTL at two distinct layers:
+
+**1. Log-layer fraud (operator rewrites or forks history).** Here the
+resemblance is nearly literal, and it is exactly what this corpus
+mechanized. Theorem 3 (`extractCons_correct` / `acceptCons_sound`)
+states: if the verifier accepts a consistency proof between a pinned
+head and a rewritten history, the named extractor **outputs a SHA-256
+collision as two concrete byte strings**. That is a fraud proof in the
+strict sense — and a constructive one: the adversary's own accepted
+messages are compiled into the evidence against them. Equivocation has
+the same shape: two conflicting signed heads ARE the fraud proof, and
+the consumer's pin-store is the watchtower that collects them. Even
+the rollup's liveness assumption transfers: someone must actually
+watch (a pinned consumer, a mirror, a `witness-audit` run). An
+unwatched log, like an unwatched rollup, is safe only on paper.
+
+**2. Claim-layer fraud (a leaf's content is a lie).** The log does not
+validate Lean proofs on append — it records the claim. That is the
+optimistic part. The fraud proof here is **replay**: the leaf pins
+everything needed to re-run the check, and the failed replay is the
+demonstration. Two properties compare favorably with rollups: the
+challenge window is *infinite* (append-only preserves the crime scene
+forever — a false leaf cannot be reverted, only exposed, and its
+permanence is the exposure), and no adjudicator is needed — the fraud
+proof is reproducible by every reader independently.
+
+**Where the analogy honestly stops: enforcement.** A rollup's fraud
+proof triggers protocol-native consequences — state reverts, bonds are
+slashed, money moves. The LTL has no bond, no slashing, no revert.
+Evidence leads to out-of-band consequences (consumers stop trusting;
+the evidence is publicized), exactly as in CT, where the "slash" is a
+browser distrusting a CA. Same detection architecture, different
+enforcement layer: cryptographic accountability with reputational
+rather than economic stakes. Bolting on economic slashing would
+require on-chain adjudication of "the Lean replay failed" — a
+fraud-proof VM able to run a proof checker; theoretically the same
+construction rollups use, practically a research program. The
+pragmatic dual, implemented in this estate, is consumer-side defense:
+warden's quorum of independently attested verifiers, instead of
+prover-side bonding.
+
+**The inversion worth savoring.** Rollup design treats "optimistic +
+fraud proofs" and "validity proofs" as competing answers for the same
+object. This stack uses both, one inside the other: each leaf's
+*payload* is validity-proven in the strongest available sense (the
+Lean kernel — no optimism, no challenge window), while the *envelope*
+carrying it is optimistic/accountability-style. And entry 13 closes a
+loop that optimistic rollups themselves aspire to and largely lack:
+**formally verified fraud-proof machinery**. The mechanized theorems
+say precisely "this fraud-proof system cannot fail to convict" — any
+accepted rewrite yields the collision, constructively. Production
+rollups would love a kernel-checked proof of their fault-proof
+interpreters; this log will carry one for its own — inside the very
+ledger it protects.
+
+## Pointers (for the eventual blog rendering)
+
+- Mechanized statements: `STATEMENT-MAP.md` (this repo); the fraud-
+  proof-generator reading of Theorem 3 is `extractCons_correct` +
+  `acceptCons_sound`; scope boundaries in `KNOWN-GAPS.md` (esp. gap 14:
+  the deployed-verifier side condition; gap 4: the signature layer,
+  where equivocation-evidence transferability lives).
+- Deployed anatomy: leaf → `entries/NNNNNN.json`; head →
+  `latest-sth.json` (+ `sth-history.jsonl`); the head is signed by the
+  dogfooded verified-dalek backend (`self_inclusion: verified`).
+- Lineage: RFC 9162 / Certificate Transparency — the original
+  accountability-over-validity system; the LTL is CT's discipline
+  applied to formal-verification claims.