Pith Number

pith:IM6XYWZ5

pith:2012:IM6XYWZ5Y2ME5TIVUIPUBXKLPI

not attested not anchored not stored refs pending

Unshuffling a Square is NP-Hard

Michael Soltys, Sam Buss

arxiv:1211.7161 v1 · 2012-11-30 · cs.CC

Open paper page JSON Open Graph Bundle Merged state Verified badge What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{IM6XYWZ5Y2ME5TIVUIPUBXKLPI}

Prints a linked badge after your title and injects PDF metadata. Compiles on arXiv. Learn more · Embed verified badge

Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Receipt and verification

First computed	2026-05-18T03:39:31.482511Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

433d7c5b3dc6984ecd15a21f40dd4b7a38b47a3f03b7a65e11fcaabcd5f99bb7

Aliases

arxiv: 1211.7161 · arxiv_version: 1211.7161v1 · doi: 10.48550/arxiv.1211.7161 · pith_short_12: IM6XYWZ5Y2ME · pith_short_16: IM6XYWZ5Y2ME5TIV · pith_short_8: IM6XYWZ5

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/IM6XYWZ5Y2ME5TIVUIPUBXKLPI \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: 433d7c5b3dc6984ecd15a21f40dd4b7a38b47a3f03b7a65e11fcaabcd5f99bb7

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "10fb3a8017c68843e435e3a064fdfab598fec56bbf36ba8b7d0b821ce6d0a325",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.CC",
    "submitted_at": "2012-11-30T06:14:06Z",
    "title_canon_sha256": "4a0c40420281b3adc0fc08b736d05f90c167b4afb8b76927c0d89397268914d5"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1211.7161",
    "kind": "arxiv",
    "version": 1
  }
}