research(urpcs): independently replay v1 decoder

.github/workflows/urpcs.yml

@@ -22,6 +22,11 @@ jobs:
       - uses: actions/setup-python@v6
         with:
           python-version: "3.12"
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+      - name: Independent decoder replay
+        run: node research/urpcs/tests/test_independent_decoder.js
       - name: Reference codec and committed-vector checks
         run: python -m unittest discover -s research/urpcs/tests -p 'test*.py'
       - name: Python syntax

AGENTS.md

@@ -124,7 +124,7 @@ coherence; it does not replace workspace behavioral tests.
   independent repository/release authority boundary.
 - Python Gonol Construction has distinct stack-local authority but has not yet gained an
   independent repository/release authority boundary; exact UCNS affixiation geometry is unresolved.
-- URPCS has bounded deterministic codec evidence but lacks an independent decoder,
+- URPCS has bounded reference and independent-decoder evidence but lacks a
   confidentiality model, durable host-state proof, and independent release authority.
 - The complete root `skill-lib/` snapshot refresh remains separate because the current
   provenance-bound fresh-making doctrine is newer than the local generator snapshot.

README.md

@@ -95,13 +95,15 @@ EPAC retains implementation and public-contract authority; Stack owns only the
 local carrier audit and its bounded receipts.
 
 URPCS v1 is a separate stack-local codec experiment at `research/urpcs/`. It
-carries accepted Laws 1–13, an authenticated reference encoder/decoder, and
-byte-exact vectors. Its codec-local `Gonol` row is not a UCNS gonol; the workspace
-imports no PCEA construction and claims no confidentiality or production fitness.
+carries accepted Laws 1–13, an authenticated reference encoder/decoder, an
+independently structured decoder, and byte-exact vectors. Its codec-local `Gonol`
+row is not a UCNS gonol; the workspace imports no PCEA construction and claims no
+confidentiality or production fitness.
 
 ```bash
 python3 research/urpcs/urpcs_v1_reference.py --self-test
 python3 -m unittest discover -s research/urpcs/tests -p 'test*.py'
+node research/urpcs/tests/test_independent_decoder.js
 ```
 
 ### Change stack structure
@@ -132,8 +134,9 @@ English Gonol Construction is currently a distinct stack-local research componen
 separated from EDCM but not independently graduated.
 Python Gonol Construction is likewise stack-local and ungraduated; its Python 3.12
 constructor is an implemented candidate, not stack or language canon.
-URPCS is stack-local and ungraduated; its verified reference vectors establish
-deterministic codec behavior, not encryption security.
+URPCS is stack-local and ungraduated; its verified reference vectors and
+independent replay establish bounded deterministic codec behavior, not
+encryption security.
 Psychsocio metafauna and From Photons to the Macroverse remain stack-local
 pre-graduation research. EPAC has an independently published MPL-2.0 `v0.1.0`
 release and has passed public Stack reconsumption. Its Python forge copy is retired;
@@ -216,8 +219,9 @@ merge.
   independent repository/release authority boundary.
 - Python Gonol Construction has distinct stack-local authority but has not yet gained an
   independent repository/release authority boundary; UCNS affixiation geometry remains unresolved.
-- URPCS has a deterministic authenticated-codec reference profile but no independent
-  decoder, confidentiality model, production state store, or release authority.
+- URPCS has a deterministic authenticated-codec reference profile and bounded
+  independent decoder evidence, but no confidentiality model, production state
+  store, or release authority.
 - Actual VM PostgreSQL/service-account/storage state and the independent backup device
   remain deployment observations until inspected on the VM.
 - A GitHub-hosted executor remains optional and unimplemented; VM-local execution is the

STACK_MANIFEST.md

@@ -15,7 +15,7 @@ Provenance and authority-boundary record for `The-Interdependency/stack`.
 - URPCS v1 workspace integration UTC: `2026-09-20` from Stack baseline `a428a41a38a8b30bacb7025a4d54070b228a8089`
 - Stack-manifest schema: `the-interdependency.stack-manifest` version `1.1.0`
 - Work-graph digest (SHA-256 over canonical `repositories` + `research_participants` + `boundaries` JSON):
-  `39af341f00c85c137bb8e239aeb1afc00939a542b8f3f09cb371c522313a0d0d`
+  `99aa9e4dfd0a9b4f37d2aefe751247cb918230bc6672bd9a2f2452bae6ab82b4`
 - Machine-readable copy: [`stack-manifest.json`](stack-manifest.json)
 
 ## Directory contract
@@ -171,13 +171,14 @@ constructor has no independent repository/release authority, and its successful
 transfers no semantic, geometric, measurement, or language-canon status.
 
 URPCS is likewise stack-local and ungraduated. The reference implementation and
-fixtures are executable evidence for one bounded profile; an independent decoder,
-confidentiality model, durable host state, and production-security review remain open.
+fixtures are executable evidence for one bounded profile, and an independently
+structured decoder reproduced its committed outputs. A confidentiality model,
+durable host state, and production-security review remain open.
 
 ## hmmm
 
 - UCNS has no `LICENSE` file at pinned commit `828c0b8`.
 - English Gonol Construction remains stack-local research; independent repository/release authority and the exact UCNS displacement law have not been established.
 - Python Gonol Construction remains stack-local research; independent repository/release authority and exact UCNS affixiation geometry remain unresolved.
-- URPCS remains stack-local research; independent interoperability, confidentiality, durable rollback resistance, and release authority remain unresolved.
+- URPCS remains stack-local research; bounded independent decoding survived, while confidentiality, durable rollback resistance, and release authority remain unresolved.
 - `skill-lib/` remains a special operational snapshot at stack root rather than following the ordinary `libs/` + `research/` pair.

docs/work-graphs/repository-plan-report.json

@@ -70,16 +70,16 @@
     },
     {
       "surface": "research/urpcs/",
-      "status": "Laws 1-13 freeze summary, reference encoder/decoder, eight named vectors, exhaustive one-byte depth-zero check, source receipt, and CI gate integrated",
-      "boundary": "Stack-local authenticated-codec computation only; confidentiality, PCEA compatibility, UCNS-gonol identity, independent interoperability, and release authority remain unclaimed."
+      "status": "Laws 1-13, reference encoder/decoder, independent JavaScript decoder replay, byte-exact vectors, source receipt, and CI gates integrated",
+      "boundary": "Stack-local authenticated-codec computation only; bounded independent decoding survived, while confidentiality, PCEA compatibility, UCNS-gonol identity, and release authority remain unclaimed."
     }
   ],
   "active_frontier": [
     "refresh pinned repository views when owners advance and a stack experiment needs the newer state",
     "register organization aggregate and website projection derivations in the fresh-making control plane",
     "maintain EPAC as a hash-pinned independent release consumer",
     "Maintain Python and English Gonol construction/replay as bounded Stack research against their declared source and geometry identities.",
-    "Obtain an independently written URPCS decoder and a leakage/threat model before considering any confidentiality construction."
+    "Obtain a URPCS leakage/threat model before considering any confidentiality construction."
   ],
   "next_actions": [],
   "blocked": [],
@@ -139,6 +139,6 @@
     "skill-lib remains a special operational root snapshot rather than the normal libs/research pair",
     "EPAC geometry ratification and unmeasured operation effects remain unresolved research",
     "Python Gonol exhaustive CPython 3.12 grammar/test-corpus parity, later language profiles, and exact UCNS affixiation/coupling operations remain unresolved.",
-    "URPCS independent decoding, confidentiality, durable rollback resistance, fork recovery, and production suitability remain unresolved."
+    "URPCS confidentiality, durable rollback resistance, fork recovery, and production suitability remain unresolved."
   ]
 }

research/urpcs/README.md

@@ -32,6 +32,8 @@ UCNS geometry, or UCNS-gonol identity.
   complete forward/reverse composition, and exact wire/state rules.
 - [`urpcs_v1_reference.py`](urpcs_v1_reference.py) — dependency-free reference
   encoder, decoder, state advance, and fixture generator.
+- [`urpcs_v1_independent.js`](urpcs_v1_independent.js) — independently structured,
+  dependency-free decoder built from the public contract.
 - [`vectors/urpcs-v1-vectors.json`](vectors/urpcs-v1-vectors.json) — byte-exact
   positive and negative fixtures.
 - [`docs/URPCS-v1-vector-report.md`](docs/URPCS-v1-vector-report.md) — measured
@@ -40,6 +42,8 @@ UCNS geometry, or UCNS-gonol identity.
   — frozen independent-decoder sufficiency audit and exact public-input identities.
 - [`docs/URPCS-v1-public-contract-repair.md`](docs/URPCS-v1-public-contract-repair.md)
   — repair scope, preservation boundary, and clean-room replay gate.
+- [`docs/URPCS-v1-independent-replay.md`](docs/URPCS-v1-independent-replay.md)
+  — frozen clean-room replay identities and `SURVIVED_INDEPENDENTLY` result.
 - [`SOURCE_RECEIPT.json`](SOURCE_RECEIPT.json) — imported-artifact identities.
 
 ## Usage guidance
@@ -63,6 +67,13 @@ cmp /tmp/urpcs-v1-vectors.json \
 The harness accepts at most one plaintext byte and recursion depth one. It is an
 interoperability fixture, not an application API.
 
+Run the independent decoder checks:
+
+```bash
+node research/urpcs/urpcs_v1_independent.js --kat
+node research/urpcs/tests/test_independent_decoder.js
+```
+
 ## Verified reference result
 
 - 8/8 named fixtures pass.
@@ -74,20 +85,28 @@ interoperability fixture, not an application API.
 The last result makes the resource boundary concrete: this is not a compressor,
 and greater depths require a separately justified permitted-domain cap.
 
+## Verified independent result
+
+- `empty_r0`, `empty_r1`, and `odd_09_r0` reproduce the committed plaintext,
+  deterministic receipt, and complete successor state.
+- Wrong associated data and an authenticated-body mutation are rejected at tag
+  verification before state advance.
+- The independent KMAC256 implementation matches NIST SP 800-185 Sample #4 and
+  an external OpenSSL `KMAC-256` result.
+- The decoder was frozen before the first ciphertext comparison and required no
+  correction afterward.
+
 ## Next gates
 
-1. Run a fresh clean-room decoder audit using the repaired public specification
-   as its only URPCS law source; compare expected outputs only after freezing the
-   implementation.
-2. A threat model and leakage model must precede any confidentiality claim.
-3. Host-side durable compare-and-swap, crash recovery, rollback resistance, and
+1. A threat model and leakage model must precede any confidentiality claim.
+2. Host-side durable compare-and-swap, crash recovery, rollback resistance, and
    fork policy require implementation and adversarial testing.
-4. Any future relation to PCEA or UCNS requires a separate authority-bearing law;
+3. Any future relation to PCEA or UCNS requires a separate authority-bearing law;
    repository proximity supplies none.
 
 ## hmmm
 
-The frozen audit is `BLOCKED_NOT_INDEPENDENTLY_SPECIFIED` for its old input. The
-public contract has since been repaired without changing reference code or
-vectors. Independent interoperability remains the next gate: the door is now
-specified, but a clean-room implementation still has to walk through it.
+The frozen audit remains `BLOCKED_NOT_INDEPENDENTLY_SPECIFIED` for its old input.
+After the public contract repair, the clean-room replay is
+`SURVIVED_INDEPENDENTLY` for the committed bounded profile. Confidentiality,
+durable host state, production security, and release authority remain open.

research/urpcs/WORK_GRAPH.json

@@ -1,7 +1,7 @@
 {
   "schema": "the-interdependency.stack-manifest",
   "version": "1.0.0",
-  "work_graph_sha256": "1242de61073ee36ef1255cbac9d7835142c0f1712b4d1213ef6960b7832a4bcf",
+  "work_graph_sha256": "808d98a91d8dac553da17ec0bb2fb71b208318c609014faad818efc750dc4e78",
   "repositories": [
     {
       "repository": "The-Interdependency/stack",
@@ -23,9 +23,9 @@
     "semantic_mapping": "external-provenance",
     "agent_scope": "cross-repository-work-graph",
     "hmmm": [
-      "independent decoder interoperability is untested",
+      "independent decoder interoperability survived for the committed bounded profile",
       "confidentiality and production security are unclaimed",
-      "the full accepted Laws 1-13 are public, but clean-room decoder replay remains pending",
+      "the full accepted Laws 1-13 are public and the frozen clean-room decoder replay passed",
       "URPCS codec-local Gonol records are not UCNS gonols"
     ]
   }

research/urpcs/docs/URPCS-v1-independent-replay.md

@@ -0,0 +1,129 @@
+# URPCS v1 independent decoder replay
+
+**Frozen:** 2026-09-21
+
+**Public-contract base:** `d3a38d4ef5e401bc43902face41f805462d88877`
+
+**Implementation freeze:** `5d205978f2a034969782e743c59f62aca83fc92c`
+
+**Classification:** `SURVIVED_INDEPENDENTLY`
+
+An independently structured JavaScript decoder reproduced the committed URPCS
+v1 plaintexts, deterministic receipts, and successor states. It also rejected
+wrong associated data and an authenticated-body mutation at tag verification.
+
+The decoder was constructed from `docs/urpcs-v1-spec.md`, the committed vector
+JSON, framing bytes, and source receipt. Before the implementation freeze and
+first vector comparison, its construction did not import, copy, or inspect
+`urpcs_v1_reference.py` or its tests. Expected plaintext, receipt, and successor
+state values are supplied only to the comparison harness after `decode` returns;
+the decoder itself receives the committed ciphertext, initial state, and
+associated-data bytes directly.
+
+This result preserves URPCS as Stack-local authenticated-codec research. It
+makes no confidentiality, encryption-security, production-suitability,
+PCEA-compatibility, or UCNS-gonol claim.
+
+## Frozen artifacts
+
+| artifact | SHA-256 |
+|---|---|
+| repaired public specification | `295cd721a19475e683b1831f1a15b3c7eed521cec551d68cd031bfed4757423e` |
+| committed vector JSON | `1d96299a016feed6f2e0881a5d4d21c20229714dab5eaa9338008d5282c2dfe6` |
+| independent decoder at freeze | `c9490f772b41934ba1c878a2d081477974ef19387f048ed489359ea8bfda089d` |
+| independent replay harness at freeze | `8fb1af64a87249755157ee1f72ed92fa82bf807fa8513e2e9f87966de99c2bc8` |
+
+The implementation freeze preceded the first ciphertext replay. No decoder
+correction was required after that comparison.
+
+## Exact replay identities
+
+All positive vectors use these 15 associated-data bytes:
+
+```text
+555250435320766563746f72207631
+```
+
+Their SHA-256 identity is
+`b9663436beff15b0563d459bc761826b4c5a316f7350f106be02f7c3675c2745`.
+
+| vector | ciphertext bytes / SHA-256 | recovered plaintext | deterministic receipt |
+|---|---|---|---|
+| `empty_r0` | 205 / `60fc120c11bb02533aef7f8cf0ad62ff2b09b26571998fd3adaae800e8c58552` | empty | `528070861f8226b8518c39707e05f4841724b315256e588cf2d5c3e8c5926426` |
+| `empty_r1` | 146,210 / `eb17f5674651d83ba79065bab09bba2c405aec6732915ca9fc06a3ddb68ad565` | empty | `1432924dd876e1fec74ad7b04084309bce62fc7ad98fde5cd250b607b68eff74` |
+| `odd_09_r0` | 2,534 / `878f3f828afcc27fd55ea5daaf240710bd09ae05d2a68dc4ea943309c0a57173` | `09` | `294734d163bf393292465421d7384a56cf7d07fc00a515beadd4d6483ebd93f1` |
+
+The independently derived successor states exactly equal the committed states:
+
+| vector | next `k_pair` | next `k_integrity` | next `k_advance` | next `nu_origin` | `R_cap` |
+|---|---|---|---|---|---:|
+| `empty_r0` | `264799e279acd7204425a174e26893dd8aa9f2524e96d124aaa58c3efe751124` | `86e9d0da678bd21bd3ac50f300236f1c3f8c00b7e0da9ae2174c74c749873cda` | `874a8872a56f50dfb6cddcab8aa82571573c24eee4e81434cf32bb60c3bfe3e4` | `0000000000000000000000000000000000000000000000000000000000000001` | 0 |
+| `empty_r1` | `81d0a453e4eb0710eac2efaf82fc48a5b0ea6bfa25eef96396d197784cd9ea97` | `44fbd6ae562a7761aa58db4b11c9c40122983b181ca5a7b090092211ad766fb3` | `f918b5ece11d3dd5d258e7c5324e58ebe2c281c6ec7d44637aeaf0fc43aa9d72` | `0000000000000000000000000000000000000000000000000000000000000001` | 1 |
+| `odd_09_r0` | `60066a03db229c15c3ef97cc908ebff6b1682f08668ea8e49cd86f6cdb3be4a0` | `ddfd57437a7244a44bc0b70ea88190723574ea2714f4d1ab2a343be3f16aef46` | `dcad41208c9bb3585d6a16dfa2f439c5b827a63998b726d4b0abf6968d6d94b0` | `0000000000000000000000000000000000000000000000000000000000000001` | 0 |
+
+## Authentication rejection
+
+- The 16-byte wrong associated data
+  `555250435320766563746f7220763121` has SHA-256
+  `70736147b2dc31d6a78163e18d73c32cf03c86356c02eec909d06fda57a9b632`
+  and is rejected at tag verification.
+- The 2,534-byte authenticated-body mutation has SHA-256
+  `94de735983fe1fe37ffec2bf4b6c0140523a0a18edae7a3708537c1f6f62d828`.
+  It changes zero-based ciphertext offset 1,986 from `0x55` to `0x54` and is
+  rejected at tag verification.
+
+Both failures occur before bootstrap parsing, plaintext recovery, receipt
+construction, or state advance.
+
+## Independent KMAC256 check
+
+The decoder contains its own BigInt Keccak-f[1600], cSHAKE256, and KMAC256
+implementation. Before ciphertext replay, it reproduced NIST SP 800-185 KMAC
+Sample #4 for key bytes `0x40` through `0x5f`, data `00010203`, customization
+string `My Tagged Application`, and a 64-byte output:
+
+```text
+20c570c31346f703c9ac36c61c03cb64c3970d0cfc787e9b79599d273a68d2f7
+f69d4cc3de9d104a351689f27cf6f5951f0103f33f4f24871024d9c27773a8dd
+```
+
+OpenSSL's external `KMAC-256` implementation reproduced the same official
+known-answer output. This confirms the primitive implementation and does not
+make an encryption-security claim for URPCS.
+
+## Usage guidance
+
+Run the independent KMAC known-answer check:
+
+```bash
+node research/urpcs/urpcs_v1_independent.js --kat
+```
+
+Decode one committed vector from ciphertext, state, and associated data:
+
+```bash
+node research/urpcs/urpcs_v1_independent.js \
+  --vector empty_r0 research/urpcs/vectors/urpcs-v1-vectors.json
+```
+
+Run the full independent replay and negative checks:
+
+```bash
+node research/urpcs/tests/test_independent_decoder.js
+```
+
+## Claim boundary
+
+- **Established:** the repaired public contract is sufficient for an
+  independently structured decoder to reproduce the three required plaintexts,
+  receipts, successor states, and authenticated rejection behavior.
+- **Preserved:** the historical blocked audit remains correct for its older,
+  incomplete specification input.
+- **Unclaimed:** confidentiality, encryption security, production suitability,
+  PCEA compatibility, UCNS-gonol identity, or independent release authority.
+
+## hmmm
+
+The mirror has a door for the committed bounded profile. That door establishes
+independent decoding interoperability, not a security model or production
+system.