{"query": "Hardness — security is a hard problem", "count": 20, "results": [{"id": "card_crypto_hardness", "title": "Hardness — security is a hard problem", "shelf": "codex", "surface": "secular", "snippet": "RSA is secure only because factoring n into its primes is believed hard; break that (or prove P = NP, or run Shor's quantum algorithm) and it falls. Security IS a hardness assumption. Rests on the P v", "authority_tier": "engine_derived", "source": "Narrow Highway — cryptography", "readable": false, "generated": false}, {"id": "card_theory_quantum_information___entanglement__von_neumann_entr", "title": "Quantum information & entanglement (von Neumann entropy)", "shelf": "theories", "surface": "secular", "snippet": "Quantum information & entanglement (von Neumann entropy) — an engine domain that can touch it: information_theory. Calibration: seals. S = -Tr(ρ log ρ), the entropy of a density matrix, which reduces ", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "readable": false, "generated": false}, {"id": "card_theory_diffie_hellman_key_exchange", "title": "Diffie-Hellman key exchange", "shelf": "theories", "surface": "secular", "snippet": "Diffie-Hellman key exchange — an engine domain that can touch it: cybersecurity. Calibration: partial — specific relations verify; the theory as a whole is not a sealable computation. Two parties agre", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (lone-domain seeding)", "readable": false, "generated": false}, {"id": "card_floor_cryptography", "title": "Cryptography — public keys and hard problems", "shelf": "codex", "surface": "secular", "snippet": "Secrecy built on number theory and computational hardness. RSA encrypts with a public key and decrypts with a private one (the round-trip sealed), its security the belief that factoring is hard; the o", "authority_tier": "engine_derived", "source": "Narrow Highway — cryptography", "readable": false, "generated": false}, {"id": "card_span_5b9cfee15c39", "title": "IRON AND STEEL", "shelf": "sources", "surface": "secular", "snippet": "All commercial iron and steel contains carbon in varying \namoimts. Such characteristics as hardness, toughness and fusi- \nbility are determined by the amount of carbon contained in the \niron. The kind", "authority_tier": "primary_pd", "source": "Farm Blacksmithing (Friese, 1921)", "readable": true, "generated": false}, {"id": "card_joint_sign_problem", "title": "The lattice sign problem is NP-hard", "shelf": "codex", "surface": "secular", "snippet": "Troyer and Wiese (2005): the fermion sign problem of quantum Monte Carlo - the obstacle to simulating lattice gauge theory at finite density - is NP-hard. A proof that P = NP would remove it; its hard", "authority_tier": "engine_derived", "source": "Narrow Highway - the Millennium floor, a joint found in the literature (operator seed)", "readable": false, "generated": false}, {"id": "card_crypto_perfect_secrecy", "title": "Perfect secrecy — the one-time pad", "shelf": "codex", "surface": "secular", "snippet": "The one-time pad (XOR with a truly random key, as long as the message, used once) has provably perfect secrecy (Shannon, 1949): the ciphertext reveals nothing. Its key cost is why we usually fall back", "authority_tier": "engine_derived", "source": "Narrow Highway — cryptography", "readable": false, "generated": false}, {"id": "card_span_a3d97ef551db", "title": "HARDENING AND TEMPERING", "shelf": "sources", "surface": "secular", "snippet": "Hardening is making the tool steel as hard as possible, and \ntempering is reducing the hardness to a certain definite de- \nsired degree. \n\nHardening — Heat the tool steel to a blood red heat and plimg", "authority_tier": "primary_pd", "source": "Farm Blacksmithing (Friese, 1921)", "readable": true, "generated": false}, {"id": "card_src_etym_hardness", "title": "hardness", "shelf": "etymology", "surface": "secular", "snippet": "hardness: etymology (Webster 1913) — n.: [AS. heardness.]. From Webster's Revised Unabridged Dictionary (1913), public domain.", "authority_tier": "reference", "source": "Webster's Revised Unabridged Dictionary (1913), Project Gutenberg eBook #29765 — public domain", "readable": true, "generated": false}, {"id": "card_src_pron_hardness", "title": "hardness", "shelf": "pronunciation", "surface": "secular", "snippet": "hardness: pronounced (ARPABET) HH AA1 R D N AH0 S. From the CMU Pronouncing Dictionary — the standard machine-readable pronunciations of North American English.", "authority_tier": "reference", "source": "CMU Pronouncing Dictionary (cmudict) — BSD-2-Clause, Carnegie Mellon", "readable": false, "generated": false}, {"id": "card_src_fed_studyofrelationb00rawd", "title": "A study of the relation between the Brinell hardness and the grain size of annealed carbon steels", "shelf": "science", "surface": "secular", "snippet": "A study of the relation between the Brinell hardness and the grain size of annealed carbon steels. A United States federal publication, public domain (17 USC 105). The full text (58,167 bytes) is held", "authority_tier": "reference", "source": "US Bureau of Standards publications (PD, 17 USC 105)", "readable": true, "generated": false}, {"id": "card_src_fed_studyofrelationb01rawd", "title": "A study of the relation between the Brinell hardness and the grain size of annealed carbon steels", "shelf": "science", "surface": "secular", "snippet": "A study of the relation between the Brinell hardness and the grain size of annealed carbon steels. A United States federal publication, public domain (17 USC 105). The full text (61,106 bytes) is held", "authority_tier": "reference", "source": "US Bureau of Standards publications (PD, 17 USC 105)", "readable": true, "generated": false}, {"id": "card_isbe_hardly_hardness", "title": "ISBE: Hardly; Hardness", "shelf": "encyclopedia", "surface": "witness", "snippet": "See HARD .\n\n\u0000\n\nThe full 1915 article renders on this card's page.", "authority_tier": "reference", "source": "International Standard Bible Encyclopedia (1915), ed. James Orr — Public Domain (CrossWire SWORD module ISBE v2.2)", "readable": false, "generated": false}, {"id": "card_src_etym_induration", "title": "induration", "shelf": "etymology", "surface": "secular", "snippet": "induration: etymology (Webster 1913) — n.: [Cf. F. induration, L. induratio hardness of heart.]. From Webster's Revised Unabridged Dictionary (1913), public domain.", "authority_tier": "reference", "source": "Webster's Revised Unabridged Dictionary (1913), Project Gutenberg eBook #29765 — public domain", "readable": true, "generated": false}, {"id": "card_src_etym_duramen", "title": "duramen", "shelf": "etymology", "surface": "secular", "snippet": "duramen: etymology (Webster 1913) — n.: [L., hardness, a hardened, i. e., ligneous, vine branch, fr. durare to harden. See Dure.]. From Webster's Revised Unabridged Dictionary (1913), public domain.", "authority_tier": "reference", "source": "Webster's Revised Unabridged Dictionary (1913), Project Gutenberg eBook #29765 — public domain", "readable": true, "generated": false}, {"id": "card_src_etym_cornel", "title": "cornel", "shelf": "etymology", "surface": "secular", "snippet": "cornel: etymology (Webster 1913) — n.: [OF. cornille, cornoille, F. cornouille, cornel berry, LL. cornolium cornel tree, fr. L. cornus, fr. cornu horn, in allusion to the hardness of the wood. See Hor", "authority_tier": "reference", "source": "Webster's Revised Unabridged Dictionary (1913), Project Gutenberg eBook #29765 — public domain", "readable": true, "generated": false}, {"id": "card_src_etym_adamantine", "title": "adamantine", "shelf": "etymology", "surface": "secular", "snippet": "adamantine: etymology (Webster 1913) — a.: [L. adamantinus, Gr. 1. Made of adamant, or having the qualities of adamant; incapable of being broken, dissolved, or penetrated; as, adamantine bonds or cha", "authority_tier": "reference", "source": "Webster's Revised Unabridged Dictionary (1913), Project Gutenberg eBook #29765 — public domain", "readable": true, "generated": false}, {"id": "card_theory_computational_complexity__p__np__reductions", "title": "Computational complexity (P, NP, reductions)", "shelf": "theories", "surface": "secular", "snippet": "Computational complexity (P, NP, reductions) — an engine domain that can touch it: computer_science. Calibration: map-only — P vs NP is open, and this card says so. Not whether a problem can be solved", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "readable": false, "generated": false}, {"id": "card_theory_cryptographic_security", "title": "Cryptographic security (hashing, checksums, PKI)", "shelf": "theories", "surface": "secular", "snippet": "Cryptographic security (hashing, checksums, PKI) — an engine domain that can touch it: cybersecurity. Calibration: seals — digests and signatures verify exactly. Three different things people routinel", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "readable": false, "generated": false}, {"id": "card_theory_linear_algebra", "title": "Linear algebra (vector spaces, eigenvalues)", "shelf": "theories", "surface": "secular", "snippet": "Linear algebra (vector spaces, eigenvalues) — an engine domain that can touch it: linear_algebra. Calibration: seals. Vectors, the linear maps between them, and matrices as those maps written down. Th", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "readable": false, "generated": false}], "house": {"door": "FIND", "kind": "cards", "trail": "results", "seal": null, "next_step": {"do": "open the top card", "door": "FIND", "tool": "card_get", "params": {"id": "card_crypto_hardness"}}, "ends": "a verdict or a card · the trail · a seal · one next step"}}