CASE 013 · Punctuation-Choice Steganography

Marks Between Clauses

A four-letter signal is carried by punctuation choices. Use the recovered rule to reconstruct the message.

Advanced 325 pts Hint penalty: 40 pts

Artifact

Inspect this carefully

The desk offered one clue: a ring of dust beside the lamp. The hallway revealed another detail— one tile was newer than the rest. The watch log recorded a small anomaly: the east door opened before dawn. The cabinet held one useful trace: a blue fiber caught beneath the hinge. The window suggested a recent visit— one latch carried a fresh scratch. The stairwell preserved a faint sign— damp grit marked the third step. The notebook contained a repeated phrase: every entry mentioned the river. The map showed one unusual feature— a narrow road ended beside the quarry.

The radio transcript gave a timing clue: the final call ended at midnight. The workshop left a mechanical hint— one wrench was still warm. The garden path supplied another sign: gravel had shifted near the wall. The archive exposed a filing error: one folder carried two dates. The pantry revealed a quiet inconsistency— the upper shelf had been wiped clean. The garage offered a directional clue: tire dust pointed toward the service lane. The clock provided a narrow window: its stopped hands fixed the hour precisely. The locker contained one odd item— a dry glove beside a wet coat.

The courtyard preserved a brief pattern: three footprints crossed the loose soil. The receipt added a location clue— the purchase came from a station kiosk. The elevator log showed one interruption: the car paused between floors. The roofline offered a visual sign— one antenna had been turned west. The storeroom contained a simple mismatch: one crate seal used newer tape. The bridge camera captured one detail: a hooded figure carried no bag. The schedule exposed a short gap— twelve minutes had no recorded activity. The basement wall showed a recent repair— fresh mortar covered an old opening.

The ledger contained one numerical clue: a payment repeated every seventh day. The doorway preserved a transfer mark— pale paint clung to the lower frame. The terminal history showed a pattern: one session ended without a logout. The fence line revealed a passage— two wires had been bent apart. The storage tag supplied a naming clue: the same initials appeared on three boxes. The mirror offered a final visual detail— a corner had been cleaned by hand. The corridor camera provided the last timing clue: the lights dimmed just before entry. The field notes ended with one conclusion: the clues belonged to a single route.

Recovered punctuation rule

Read only colons and em dashes inside the field-note prose, from left to right. A colon represents 0 and an em dash represents 1. There are 32 carrier marks; group them into four 8-bit ASCII bytes.

Machine View Inspect alternate representations

Compare the rendered artifact above with representations derived from the same browser-delivered artifact. Machine View does not decode, score, or identify the hidden message.

Opening a representation may expose clues that are already present in the page source or DOM.

Source Browser serialization

            
Text DOM textContent

            
Characters Unicode code points

            

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    About the technique

    Punctuation-Choice Steganography

    Punctuation-choice steganography uses deliberately selected punctuation states as symbols. A colon and an em dash can both introduce an explanation in carefully curated sentences, but the hidden channel remains fragile because editors, formatters, copy/paste pipelines, or style normalization may replace or remove the exact marks.

    Read the related field guide →

    Questions

    Frequently asked

    What is punctuation-choice steganography?

    It is a hidden-information method that assigns symbols such as binary 0 and 1 to predefined punctuation alternatives used at known carrier positions.

    Are punctuation marks always interchangeable?

    No. A colon, em dash, comma, semicolon, and period have different grammatical and rhetorical roles. A safe demonstration must curate each sentence so the selected alternatives remain valid in that exact context.

    Why is punctuation steganography fragile?

    Reformatting, copy/paste, typography normalization, style editing, or automatic rewriting can replace punctuation marks and therefore flip or delete encoded symbols.