igneum/docs/analysis/cryptanalysis/report-chained-cache-3.md

Report: the chained cache, chain break or skip (lane adv-cache-3)

Internal adversarial pass, not an independent review. Lane adv-cache-3, the chain-break-or-skip class of the chained cache (line (s, j) in fewer than j + 1 blocks without an earlier line; relations through the XOR chaining and the feed-forward; partial knowledge; the pebbling curve). Plan: docs/plans/cryptanalysis/plan-chained-cache-3.md. Every sentence here that could be quoted publicly carries the label: internal adversarial pass, not an independent review.

Header

Item	Value
Target commit	017e70376489251e18564c0abce7e466e606c8b3 (class v4 sub-version 3, object byte 7); igneum-pow at build/master 04c4d9bc is byte-identical (git diff --quiet 017e7037 HEAD -- igneum-pow printed IDENTICAL at 19:42 BST), and the harness depends on it by path
Harness	tools/attack/adv-cache-3/ (crate attack-adv-cache-3, binary adv-cache-3), branch adv-cache-3 on the build mirror
Binary sha256	37a7a661c548a67827e29c4134bb91751ef2083920b386d3ebc9b599add3ca8a (built on both boxes from commit 4e363b91's tree, cargo build --release, rustc 1.99.0; the first build 067ad69c... had 66 rank samples per j instead of 4,096 and was replaced before any number below)
Self-test on every start	the restated B equals the library's chacha_block on 4,096 random inputs; core_inv inverts core at w = 2, 4, 8, 16, 32; the restated chain equals Cache::fill_segment on segments 0, 21,859 and 65,535 of day 20730
Vectors passed	day 20730 cache FNV-1a 64 0x448274a57f508cbc (the kit's vectors.json) and day 20733 0x7334fa46e5d972eb (the Devnet 3 pack): MATCH, check.log
Boxes and scheduling	build box 1 (the skip, relations and cross batches) and build box 2 (the exhaustive image census), each under the per-box sweep lock (/srv/builds/_adv/locks/sweep.lock, one sweep per box at a time, the coordinator's rule of 19:55 BST), nice 10 on cores 8 to 95, no SIGSTOP yield; the boxes read load 500 to 560 on 96 threads all evening, so wall times below are not timings
Logs	/srv/builds/_adv-cache-3/logs/<tag>.log on each box (outside the worktree mirror); copies under docs/analysis/cryptanalysis/logs/adv-cache-3/ on this branch
THE QUEUE	files 90, 91, 92 (the coordinator's definitions) claimed at 19:49 BST with owner files; their implementations run as files 93 (skip batch), 94 (relations batch) and 95 (image census), claimed the same way
Box-hours	section 9

Status board

#	Question	Method	Known-failed shape (fired?)	Gate	Result	Status
Q1 (brief a, file 90)	Line (s, j) in fewer than j + 1 blocks without an earlier line	skip: 7 earlier-line-free templates (1 or 2 blocks) against every line of 1,024 segments x 64 lines on 2 day keys; the GF(2) rank of the 1,025-column (x_j, line_j, 1) sample matrix; the 512 x 512 bit-dependence table and the 16 x 16 word table; the inversion attempt; the w = 4 model at 65,536 segments x 16 lines	no-xor, no-feedforward, --rounds 0	0 lines under j + 1; rank 1,025; no zero cell; plants fire	first run on day 20730: 0 of 65,536 lines under j + 1 by any template; pooled rank 1,025 of 1,025; flip table worst z +4.44 / -4.53 with 0 zero cells of 262,144; every output word changes with every input word; 0 inversions of 64,512	RUNNING
Q1 (4)	Exhaustive image census at w = 2 (every 2^32 state per step, depth 64)	image	no-feedforward (a permutation: the image must stay 2^32)	the image follows the random-function recursion, not slower	queued on build box 2	RUNNING
Q2 (brief b, c, file 91)	Relations through line_j = C(x_j) + x_j; partial knowledge	relations: per-bit bias of 4 relations over 4 day keys x 2^20 lines; the 512 x 512 correlation table; skip's word table and inversion	--rounds 1, --rounds 2, no-feedforward	every bias and cell within 6 sigma at 2^22 samples; 0 words from a proper subset; 0 inversions	queued behind the skip batch	RUNNING
Q3 (brief d, file 92)	The pebbling curve of the 64-line chain under storage f; the amortising adversary	pebble: DP optimum (checked against exhaustive search at 10 to 16 lines), two stride placements, ops per item and SRAM; Monte Carlo of m requests per segment, fixed and Poisson	--skip-edge 8	monotone, never under the honest curve, 9,360 at f = 1; the plant lowers f = 1/64	queued in the skip batch	RUNNING
Q4 (brief e)	Cross-segment and cross-day relations; the known-constant words	cross: 512 x 512 correlation tables at j = 0, 1, 63 across one-bit segment pairs and across days	--plant no-xor --rounds 1	every cell within 6 sigma	queued in the skip batch	RUNNING

The sections below are filled in as the rows land. Times in this file are UK time (BST).

9. Run ledger and box-hours

Run	Box	Started (BST)	Wall	Slot-hours
check, first skip (binary 067ad69c...)	1	20:06, 20:09	2 s, 1 s (3 min waiting on the sweep lock)	0.01
93 skip batch, 94 relations batch	1	queued 20:15 behind the sweep lock; never started	killed by pid file 20:20 BST under main's rule (every sweep through the build-server lane's lease pool; nothing measured was lost)	0
95 image census	2	queued 20:12 behind the sweep lock; never started	killed by pid file 20:21 BST, the same rule	0
93, 94, 96 (box 1) and 95 (box 2), re-queued	1, 2	when lease pool lands	through lease pool <threads> --owner adv-cache-3 -- <cmd>

Running total: under 0.1 box-hours of the 8 budgeted (the ask line is 16); no pod-hours (no GPU row).