{"data":{"event":{"id":"2a99406e-00df-4d06-a8d0-034a4e04d5f8","slug":"claude-fable-5-1-solves-the-cyphral-distich-a-370-year-old-cipher-3ea606d07a","title":"Claude Fable 5.1 solves Urquhart’s Cyphral Distich, a 370-year-old cipher","short_summary":"On 31 August 2026 Vals reported that Claude Fable 5.1 recovered Sir Thomas Urquhart’s 1653 Cyphral Distich in 44 minutes and then applied the same book-as-key rule to the longer Cyphral Octastich, leaving a nine-letter gap.","full_description":"On 31 August 2026 Vals reported that Claude Fable 5.1, given an open prompt to solve an unsolved historical cipher, recovered Sir Thomas Urquhart’s 1653 Cyphral Distich in 44 minutes. The cryptogram is two lines of 32 numbers at the end of Logopandecteision and had been listed among Klaus Schmeh’s Top 50 unsolved encrypted messages.\n\nThe recovered rule indexes the i-th number into the i-th of Urquhart’s 32 Proquiritations and takes the first letter of that word, yielding a self-checking royalist distich for Charles II. Fable then applied the same method to Urquhart’s longer Cyphral Octastich (285 numbers in The Jewel, 1652), recovering an ottava rima prayer except for a nine-letter gap the transcriber could not resolve from the EEBO-TCP text.\n\nThis is a documented historical-puzzle solve, not a new cryptanalytic primitive. The Distich is independently checkable from the printed book; the Octastich still needs a physical 1652 copy for the remaining letters.","ledger_type":"benefit","primary_domain_id":"056250cf-05f4-4116-957c-78323ed7f8cf","event_status":"provisional","event_date":"2026-08-31T00:00:00.000Z","discovery_date":"2026-08-31T00:00:00.000Z","first_published_date":"2026-08-31T00:00:00.000Z","last_reviewed_date":"2026-09-13T00:00:00.000Z","geographic_scope":"International","affected_population":null,"base_impact_tier":2,"base_score":"3.00","attribution_multiplier":"0.8500","evidence_multiplier":"0.3500","realization_multiplier":"0.5500","durability_multiplier":"0.9000","current_event_score":"0.441800","confidence_level":"medium","score_explanation":"A 370-year-old listed unsolved cipher is notable within historical cryptography (tier 2), not a major mathematical theorem. Attribution is to Fable 5.1 with human elicitation (0.85). Evidence is a technical blog plus a checkable Distich (0.35). Realization is a demonstrated solve, with the Octastich still incomplete (0.55). Durability is high for a recovered plaintext.","methodology_version_id":"d7881163-fb23-4e71-8625-bac1a8662c0f","original_methodology_version_id":"d7881163-fb23-4e71-8625-bac1a8662c0f","published_at":"2026-09-13T23:10:21.212Z","created_at":"2026-09-13T23:10:21.212Z","updated_at":"2026-09-14T00:14:56.501Z","flags":[],"domain_name":"Computer Science","domain_slug":"computer-science","methodology_version":"0.1"},"contributions":[{"id":"2c2ec1d3-bd7d-48e0-b6ac-80f9ce9a5759","event_id":"2a99406e-00df-4d06-a8d0-034a4e04d5f8","model_id":"19e2b5dd-4f37-446a-8344-48196c5acf5a","role_description":"Solved the Distich from the printed book and proposed the Octastich plaintext.","attribution_multiplier":"0.8500","credit_share":"1.0000","contribution_score":"0.441800","attribution_rationale":"Vals names Claude Fable 5.1 as the system that found the book-as-key rule with no mid-run human hints. Mapped onto the Claude Fable 5 named release.","attribution_confidence":"medium","first_used_date":"2026-08-31T00:00:00.000Z","model_version_if_known":"5.1","review_status":"approved","created_at":"2026-09-14T00:14:56.501Z","model_slug":"claude-fable-5","model_name":"Claude Fable 5","identity_class":"named_release","is_internal":false,"family_name":"Claude","family_slug":"anthropic-claude","organization_name":"Anthropic","organization_slug":"anthropic"}],"sources":[{"id":"b6aa9093-1a73-46d3-84bd-d47cb1cee126","event_id":"2a99406e-00df-4d06-a8d0-034a4e04d5f8","url":"https://www.vals.ai/blogs/fable-solves-cyphral-distich","canonical_url":"https://www.vals.ai/blogs/fable-solves-cyphral-distich","source_type":"other","publisher":"Vals","author":null,"publication_date":"2026-08-31T00:00:00.000Z","retrieved_at":"2026-09-13T23:10:21.389Z","title":"Claude Fable 5.1 Solves the Cyphral Distich, a 370-year-old cipher","excerpt":"Article URL: https://www.vals.ai/blogs/fable-solves-cyphral-distich\nComments URL: https://news.ycombinator.com/item?id=49688695\nPoints: 25\n# Comments: 0","content_hash":null,"source_reliability_class":"medium","is_primary_source":true,"is_independent":true,"is_peer_reviewed":false,"archived_url":null,"created_at":"2026-09-13T23:10:21.389Z"}],"claims":[{"id":"bf1a888b-a8cd-4a37-841d-ab614687c04c","event_id":"2a99406e-00df-4d06-a8d0-034a4e04d5f8","claim_text":"Claude Fable 5.1 solves Urquhart’s Cyphral Distich, a 370-year-old cipher","claim_type":"outcome","claim_status":"supported","confidence_score":null,"created_at":"2026-09-13T23:10:21.476Z","updated_at":"2026-09-14T00:14:56.501Z"}],"revisions":[{"id":"ef6a3bff-21de-45e9-9695-db00fdb3c026","event_id":"2a99406e-00df-4d06-a8d0-034a4e04d5f8","model_id":null,"previous_score":"0.000000","new_score":"0.001000","previous_factors":{},"new_factors":{"evidence":0.1,"base_score":1,"durability":0.5,"attribution":0.1,"realization":0.2},"change_reason":"Auto-published from news ingest.","trigger_type":"news_ingest","trigger_source_ids":null,"reviewer_id":null,"review_status":"published","created_at":"2026-09-13T23:10:21.558Z"},{"id":"1ebe2ac4-30f3-492a-b180-bf73a6cb9f18","event_id":"2a99406e-00df-4d06-a8d0-034a4e04d5f8","model_id":"19e2b5dd-4f37-446a-8344-48196c5acf5a","previous_score":"0.001000","new_score":"0.441800","previous_factors":{"placeholder":true},"new_factors":{"evidence":0.35,"base_score":3,"durability":0.9,"attribution":0.85,"realization":0.55},"change_reason":"Editorial review of a news-ingest placeholder: rewritten, attributed to a named system, and rescored.","trigger_type":"editorial_review","trigger_source_ids":null,"reviewer_id":null,"review_status":"published","created_at":"2026-09-14T00:14:56.501Z"}],"secondary":[]},"methodology_version":"0.1"}