def
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keyLength256
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IndisputableMonolith.Cryptography.KeyLengthFromPhiLadder on GitHub at line 54.
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51/-- Standard symmetric key lengths (bits). -/
52def keyLength80 : ℕ := 80
53def keyLength128 : ℕ := 128
54def keyLength256 : ℕ := 256
55
56theorem keyLength_doubling : keyLength128 * 2 = keyLength256 := by
57 unfold keyLength128 keyLength256; norm_num
58
59structure KeyLengthCert where
60 ratio_pos : 0 < securityLevelRatio
61 ratio_gt_one : 1 < securityLevelRatio
62 key_doubling : keyLength128 * 2 = keyLength256
63
64noncomputable def cert : KeyLengthCert where
65 ratio_pos := securityLevelRatio_pos
66 ratio_gt_one := securityLevelRatio_gt_one
67 key_doubling := keyLength_doubling
68
69theorem cert_inhabited : Nonempty KeyLengthCert := ⟨cert⟩
70
71end
72end KeyLengthFromPhiLadder
73end Cryptography
74end IndisputableMonolith