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9 Commits
| Author | SHA1 | Message | Date | |
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Marcin Pawlowski
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8cc682aa49
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Item 16: the revenue-optimal adversary is not the estimator's worst case
Both eta ceilings in sec 6.6 come from adversaries optimising something else (revenue, reorg depth), so they bound eta from above without bounding the damage from below. Optimising the estimate directly needs no ratio transform: each transition consumes exactly one block-finding event, so minimising D-hat = (canonical + p_ref * countable uncles)/events is a plain average-reward MDP over the transition table that already carries the orphan counts. One value-iteration pass, no bisection. Unconstrained, the answer degenerates -- and usefully. The optimum is pure abstention: publish nothing, adopt when overtaken, D-hat = 1 - alpha exactly, revenue zero. That is sec 6.4's withholding, which the report already shows is CORRECT measurement rather than mis-measurement, so the unconstrained objective asks the wrong question. The constrained one bites. Sweeping lam * (adversary blocks) - (contribution to D-hat) enumerates policies; the line of interest is where revenue SHARE reaches alpha, i.e. where attacking costs nothing versus mining honestly. At alpha=0.4 such a policy drives D-hat to 0.642 where the revenue-maximiser reaches 0.811 -- 17 points of extra deflation bought with the selfish premium alone. At 0.36 and 0.45 the gaps are 0.082 and 0.103. Below the 1/3 threshold nothing profitable deflates, so the exposure starts exactly where selfish mining does. This revises two claims that were about revenue but read as though they were about the adversary in general: sec 6.7's "the adversary frontier is exactly optimal selfish mining; no compounding lever remains" and sec 8.2's echo of it. Both now say the PROFIT frontier is bounded and the estimator frontier is not the same policy. Note the sweep parameter is deliberately non-monotone in revenue -- selfish mining takes a bigger share of a smaller pie, so raw block rate is maximised by honesty and large lam returns there; it enumerates policies rather than tracing a path. Also closes a fairness loop these findings opened. Sec 6.7(1) credits uncle rewards with compensating orphaned honest producers, computed on the SM1 race where every orphan is a first-fork block. Under a private chain 20-40% of the honest blocks destroyed are unreferenceable by construction, so those producers are uncompensatable at ANY w_u -- not underpaid because p_ref is low, but unreachable because no valid block may name them. The fairness guarantee inherits the same first-fork ceiling as the density repair. Logged as item 19, flagged as a protocol-design question rather than something a schedule fixes. _solve_mdp is refactored into _solve_reward/_greedy_policy/_stationary/ _policy_rates so both objectives share one implementation; optimal_policy_stats reproduces its committed figures exactly (eta 0.4413, D-hat 0.9447/0.8111 at alpha=0.4). 251 tests pass. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> |
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Marcin Pawlowski
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3708d03e22
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Private-chain (SM1) adversary in the per-node engine
Sec 6.8 recorded that "the per-node engine has no private-chain strategy", which is why every selfish result came from the global race model with uncle recovery as a free knob eta -- and why open item 5 (does the uncle cap need margin under attack-inflated orphaning?) could not be sized: a knob has no queue to overflow. adversary_strategy="selfish" adds it. The coalition mines one shared private chain and releases under the classic SM1 rules in (a, h) form: adopt when the public chain wins, match at equal length, override at a one-block lead, else wait. Only VISIBILITY is modelled -- the coalition's mining needs no special case, because a member's fork choice already builds on the private tip whenever it leads (that tip has the greatest height among blocks the member can see) and falls back to the public chain exactly when the public chain overtakes, which is the adopt branch. So the private chain forms, extends and is abandoned emergently, and the code that had to be written is the arrival matrix. Design notes worth keeping: - Private blocks reuse the sentinel `withhold` already had (never-arrives), so the existing exclusions from canonical-tip selection apply unchanged; release flips it back and gossips DIRECTLY from the producer, bypassing Blend, since an adversary has no privacy budget to respect and wants the race won. - A private chain breaks the windowed horizon's premise (a hidden block is old enough to look fully-propagated while no honest node has it, and it becomes visible LATER, which the one-way frontier pointer cannot revisit), so selfish forces the exact full scan and full matrix. - Blocks still hidden at epoch end are abandoned and hidden from the coalition too, or the canonical-tip search would crown a chain no honest node saw. Validated against Eyal-Sirer at sub-slot latency: revenue share 0.0356 vs an exact 0.0356 at alpha = 0.1, and above the closed form at higher alpha by just the margin the alpha_eff fork-amplification correction predicts (0.498 vs 0.484 at alpha = 0.4, with fork rate 0.38). Adds p_ref_honest: the reference rate over orphans produced OUTSIDE the coalition. Under a private-chain attack this diverges sharply from p_ref, and only the honest one measures the repair the report credits to uncle counting -- an attacker's own discarded blocks are its loss to bear. test_fork unpacks fork_stats positionally, so its three call sites take the new fifth value. 247 tests pass. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> |
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Marcin Pawlowski
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ef82ed614d
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Review pass: reproduce every number from its data of record, fix what did not
Correctness/completeness review of the report and simulator. Verified against the committed parquets: the sec 6.6 countable-ceiling table (cap-64 MDP sweep), sec 6.10 Result 4's depth ceilings, the sec 3.4 uncle-selection table, all adversary-variant numbers, the rho-boundary row-4 quotes (0.976 at rho=0.91, 4-sigma shortfall at 0.96, max cell 1.0024), and the sec 8.4 capstone table. Three defects found, all fixed: 1. The collapse event was not reproducible from the committed script. Study D swept only the default (random) coalition, but the one observed collapse is a whale cell; the "once in 144 runs" count came from an ad-hoc probe. The committed sweep now carries the selection axis (96 runs) and reproduces the event: 1/12 in the whale 50% cell at delta_max = 8, never at 4. All six fold-related passages now quote the committed sweep, which also retires the stale "the full dynamics never reach it" wording in the sec 6 arc, the sec 6.2 intro, row 6 and item 1 -- text that contradicted item 18 since yesterday's finding. 2. capstone.py's printout could not reproduce the report's sec 8.4 table. The report's numbers are a per-replicate-tail aggregation (each replicate burns in against its own early-stop length); the script cut the tail at the ARM's max epoch, silently dropping any replicate that stopped earlier (7 of 8 in the adversary arm) and landing one rounding step off on three cells. The script now aggregates per replicate and prints the SEM; against the existing parquet it reproduces the table exactly (1.001/0.998, 0.342+-0.009 / 0.343+-0.005, p_ref 1.000/0.990, 8 reps both arms). The report table was right all along; sec 6.8's p_ref quote (0.989, the per-arm value) is aligned to 0.990. 3. Small report fixes: slow-beta deflation rounded 0.765 -> "0.77" (now 0.76); fig13's caption now points at the fig36 ceiling instead of implying free recovery; row 5 cites the measured slow-beta standing deflation; the canonical-data paragraph lists the new studies' artifacts; the simulator README's layout block lists the new tests and scripts. Adds a unit test for reorg.countable_recovery_from_depths (the one new function that had none). 236 tests pass; the new-study parquets are copied to the main checkout's runs/, where every other study's data of record lives. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> |
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Marcin Pawlowski
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88f31340ad
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Uncle selection: the spec fixes oldest-first, so measure deviation from it
Open item 11 listed "a random (rather than oldest-first) uncle-selection draw" as an untested spec sensitivity. The spec does not leave it open: Uncle Selection in cryptarchia-v1-protocol.md has the proposer take the oldest candidates first, deterministically, because an uncle expires w_u slots after its own slot. That is exactly what every result in the report already uses, so the item is a conformance match, not a gap -- and the simulator comment calling uncle_random_p "the spec's unbiased coin" cites text the spec no longer has. What is genuinely open is deviation FROM that rule: selection is proposer-local and the uncles field is never validated. configs/uncle-selection.yaml measures the cost. A proposer that includes each candidate on a fair coin instead loses up to 0.10 in D-hat/D, and 0.063 at the recommended W = 10 once rho ~ 1 (0.902 vs 0.965, t = -8.6). At the design point the margin survives but is spent: 0.980 vs 0.997 against a 0.98 bar. The loss does not close as W grows, because a coin wastes opportunities rather than queue capacity and a well-sized window is precisely what keeps the queue short enough for that to bite. This matters for the sec 8.5 reward recommendation: the spec argues a proposer has no incentive to deviate BECAUSE uncles grant no reward, and paying them removes that argument. Also adds adversary_selection=whale (the largest holders at matched stake, for the untested concentration case). The marker is appended to key() only when non-default so every historical run's seed stays byte-identical, guarded by a test alongside the paired_streams one. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
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Marcin Pawlowski
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0510b20684
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Countable recovery under a selfish adversary: SM1 hides the first-fork cost
The countable model can reference only the first block of a fork, so a discarded chain of h honest blocks yields one countable uncle, not h. Sec 6.6 reads the estimator repair off a free knob eta and quotes it at eta = 1 -- attainable under SM1, which acts the moment the honest branch reaches length 1 and so never buries a second block. The optimal SSZ policy waits and does bury them, and there the deployed counting rules cap eta at 0.44 (alpha = 0.4, gamma = 0), landing D-hat at 0.81 rather than the 0.94 an unrestricted count gives -- and the ceiling degrades with alpha while the unrestricted value improves. So SM1 is a faithful proxy for selfish-mining revenue (0.484 vs 0.489) but not for TSI's estimator damage. selfish_mdp: carry per-branch orphan counts on the transition table so the accounting cannot drift from the race logic; optimal_policy_stats solves the policy's stationary distribution for per-event canonical/orphan rates. The per-event rates sum to 1 (every block is canonical or orphaned), which the tests assert as an independent check on the whole derivation. reorg: the same ceiling for the depth-maximising adversary -- 0.52 at alpha = 0.30 with the measured honest fork rate -- reached from the other direction. Neither adversary optimises deflation directly, so both ceilings are upper bounds on eta; that gap is logged as open item 16. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
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Marcin Pawlowski
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4baccd8d4b
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Paired design: resolve the design band with common random numbers
The unpaired comparison could not answer the question it was asked. The two uncle models draw independent RNG streams -- uncle_model is in the config key, which is what makes --old bit-reproduce earlier runs -- so the arms differed in stake draw, peering graph and every lottery outcome, each comparison paid the between-run variance twice, and the per-cell floor (+-0.0015) sat an order of magnitude above the effect. Only delta_max = 5 resolved, and only after pooling. Adds `paired_streams`: the RNG root is derived from the model- independent part of the key, so a countable cell and its --old twin get the SAME stake, graph and lottery draws and the uncle rule is the only difference. Each replicate is then a matched pair and the shared variance cancels. Trajectories still diverge after epoch 0 through the genuine feedback (a different counted density changes the next epoch's difficulty), which is the signal. The flag is deliberately NOT in key(): it selects which key the seed is derived from, so including it would perturb every historical seed. Re-verified that --old still bit-reproduces the committed 2026-07-27 rho-boundary parquet, max |delta| = 0. Results (configs/fine-delay-paired.yaml, 40 replicates per arm): - Negative control becomes an IDENTITY check. With U = 0 no reference is taken, so shared streams must give bit-identical trajectories. All 200 replicate pairs differ by exactly 0.0. Unpaired, the same control only had to agree within +-0.025 and drifted by 0.016. - Per-cell SE shrinks by a median 1.6x (1.2-2.1x); widest 95% CI goes +-0.0015 -> +-0.0010. 5/15 cells resolve at |t| >= 2 (0.75 expected by chance); the largest, U=2 at delta_max=4, is t = 4.32 and clears Bonferroni for 15 tests. - The cost is a STEP, not the ramp the unpaired data suggested: delta_max 1-3 unresolved (t = 1.1, 1.8, 1.4), then delta_max 4 AND 5 both resolve at -0.0011 (t = 4.7) and -0.0009 (t = 3.7). Whole-band pooled -0.00060 +- 0.00021, t = 5.7 -- where the unpaired estimate of the same quantity (t = 2.8) had failed correction. So the first-fork restriction costs nothing measurable up to delta_max = 3 and about 0.1% at 4-5 -- an order of magnitude below the +-0.9% per-epoch sampling noise. Two bugs found while building this, both of which would have silently produced a wrong answer: - paired_streams was missing from metrics._CONFIG_FIELDS, so it never reached the parquet; plot_fine_delay.py falls back to the unpaired test when it cannot confirm pairing, so the sweep would have completed and quietly reported the old result. Caught before the run finished; the sweep was restarted and a test now pins the field. - The U=0 control check reported FAILS on a PERFECT control: paired, the gap is exactly 0 so its SE is 0 and t is 0/0. It now checks the gap itself when the streams are shared, and falls back to the t-test only when there is real spread. §3.2a is rewritten around the paired measurement; the unpaired sweep is retained in §9 as the power comparison that motivated it. Figures 34-35 regenerated, with the control annotation and provenance reflecting the design actually used. Tests: 214 passed (was 209). ruff clean. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
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Marcin Pawlowski
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ac6a309e58
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Review fixes + high-precision design-band delay study
Acts on a correctness/completeness review of the countable uncle model and its report material. Correctness fixes in the report: - s3.4 quoted 0.998 for W_abs=10 at the 8s budget; the run says 0.9963. - s1 claimed both models >= 0.996 at U >= 1; countable U=2 delta=8 is 0.9955. Corrected to >= 0.995. - The s3.2 table presented two cells (U=1 at delta 16 and 32) as model differences. They are not resolvable: t = 0.46 and 0.47 over 5 replicates. The table now carries +-SEM and a t per cell. - s3.4 claimed the ~7-block-interval floor "carries over unchanged". Accuracy is still climbing past W=7 at every delay (8s: 0.989 -> 0.996), so the claim is dropped. The 32s curve is non-monotonic with replicate SD up to 0.22 and is now flagged as noise, not a trend. - 1-r was attributed to the first-fork restriction alone; it is the combined first-fork and capacity loss, which this measurement cannot separate. Hedged to match fig32's own axis label. Completeness: the U=0 negative control was swept but never reported. With no uncles the two models are identical by construction, yet they differ by -0.23 at delta_max=32 (t=2.1) because they draw independent RNG streams. That is the noise floor the rest of the grid must clear, and it is now in s3.2, s9, fig30 and the config header. New study (configs/fine-delay.yaml, scripts/plot_fine_delay.py, s3.2a, fig34/fig35): the design band delta_max 1-5 at 40 replicates, both models. Findings: every U >= 1 cell of both models lands in 0.998-1.001, flat in delay, while U=0 decays 0.810 -> 0.640. No individual cell resolves a model difference (widest 95% CI +-0.15pp; max t=2.59 vs Bonferroni 2.94 over 15 cells). Pooled across uncle caps the first-fork cost is monotone in delay and separates from zero only at delta_max=5 (-0.0014 +- 0.0007, t=3.7) -- below 0.15% everywhere in the band, against +-0.9% per-epoch sampling noise. Code: - deep_ref_share is identically 0 on every real countable run: for a chain block B the producer's chain below B is the counting chain below B, so the counting-side parent-on-chain re-check cannot reject what selection emitted. It is a drift alarm, not a rate. Documented as such in measure.py, the plot docstring and the config header, and pinned by a new end-to-end test. - Removed annotate_uncles: a second countable implementation that production never called, while carrying most of the selection test coverage. Tests now drive select_uncles_at_production through an annotate_via_production replay helper -- same assertions, live path. - Added tests for the two previously uncovered branches of the live selection: the pmin/below chain walk that resolves parent-on-chain for candidates whose parent sits below the window, and the occupied-slot exclusion built from the chain walk. - theory.q_effective and theory.window_miss_prob were unused and untested. Now used (the prediction figure reconstructs q_u through the identity the report quotes) and tested. The window_miss_prob test records that its "~ e^-W" docstring is the f->0 limit: the true decay is e^-1.017W at f=1/30, 16% off by W=10. - Shared sem()/recovery_rate() moved into figures_pernode.py; fig30 and fig33 regenerated with SEM error bars and the U=0 control curve. - Fixed the pre-existing E501 in bootstrap_dynamics.py; ruff clean. Report prose reworked to read standalone: the countable model is described as the rules under analysis and the former model as a labelled "unrestricted" comparison baseline, with no dated banners and no round-to-round narration. Tests: 209 passed (was 202). Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
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Marcin Pawlowski
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bd2ac7b7be
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Countable uncle model: spec counting rules, sweeps, figures
Implement the countable uncle model from the Cryptarchia spec's counting-only reference rules, and make it the simulator default. Counting rules (uncles.py, measure.py): - Only the first block of a fork (parent on the producer's chain) is referenceable and countable, which makes every reference verifiable from chain data alone. - The reference window is derived from a window-absorption parameter, w_u = W_abs/f slots (W_abs in expected block-intervals, default 10, bounded W_abs <= 0.6*k), replacing the free-standing uncle_window. - Selection skips slots already occupied on the producer's chain and takes at most one uncle per slot. - The measurement pass re-checks every rule per reference and tallies rejections as deep_ref_share. The pre-redesign model is preserved behind --old on tsi-sweep and tsi-verify. Its RNG key is byte-identical to the pre-uncle_model key, so --old bit-reproduces the historical runs. Supporting changes: uncle_model and window_absorption config surface with validation (config.py, constants.py); accuracy closed form over the effective q_u (theory.py); plumbing through tsi.py, epoch.py, sweep.py, blocktree.py, metrics.py, verify.py, figures_pernode.py. Studies and figures: - configs/countable-vs-old.yaml -- delay x U grid, run under both models on the same grid. - configs/absorption-window.yaml -- accuracy vs W_abs at U=1. - scripts/plot_countable_vs_old.py renders fig30-fig33 into reports/tsi/report-figures/. Tests: tests/test_countable_counting.py (7 cases) covering first-fork eligibility, derived-window bounds, occupied-slot exclusion, and per-reference re-checking; extensions to test_uncles.py, test_config.py, test_slot_counting.py. Full fast suite: 202 passed. Also adds CLAUDE.md (graphify project instructions) and ignores editor/local-agent state plus the vendored Equi-X benchmark clone. The reports/tsi/ prose describing this model is held back for a separate editorial pass. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> |
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Marcin Pawlowski
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24da2fc8b3
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Importing tsi-sim v3 |