Function binding interpolation branch maps to arsdh
KZG.CommitmentScheme.function_binding_interpolation_branch_maps_to_arsdh
Plain-language statement
The interpolation branch maps a function-binding violation to ARSDH.
Exact Lean statement
lemma function_binding_interpolation_branch_maps_to_arsdh {n L : ℕ}
(hn : 1 ≤ n) (hpair : pairing g₁ g₂ ≠ 0)
{τ : ZMod p} {srs : Vector G₁ (n + 1) × Vector G₂ 2} {cm : G₁}
{queryOf responseOf : Fin L → ZMod p} {accepts : Fin L → Bool} {proofs : Fin L → G₁}
(hsrs : srs = Groups.PowerSrs.generate (g₁ := g₁) (g₂ := g₂) n τ)
(hgen : srs.1[0] ≠ 1)
(hverify_all : ∀ i : Fin L, accepts i = true →
KZG.verifyOpening (g₁ := g₁) (g₂ := g₂) (pairing := pairing)
srs.2 cm (proofs i) (queryOf i) (responseOf i))
(hFBcond : functionBindingCondExt n L (τ, srs, cm, queryOf, responseOf, accepts, proofs))
{A S : Finset (Fin L)}
(hqueryS : Set.InjOn queryOf ↑S)
(hresS : findS n A cm srs queryOf responseOf = some S)
(hfs_none : List.findSome?
(fun i ↦ if srs.1[0] ^ (queryOf i).val = srs.1[1]'(Nat.lt_add_of_pos_left hn)
then some (queryOf i) else none)
(List.finRange L) = none) :
Groups.arsdhCondition n
(τ, (interpolationArsdhOutput (p := p) (G₂ := G₂) S
({ srs := srs, cm := cm, queryOf := queryOf, responseOf := responseOf,
accepts := accepts, proofs := proofs } :
FunctionBindingExtTranscript (p := p) n L G₁ G₂)).toTuple)Formal artifact
Lean source
lemma function_binding_interpolation_branch_maps_to_arsdh {n L : ℕ} (hn : 1 ≤ n) (hpair : pairing g₁ g₂ ≠ 0) {τ : ZMod p} {srs : Vector G₁ (n + 1) × Vector G₂ 2} {cm : G₁} {queryOf responseOf : Fin L → ZMod p} {accepts : Fin L → Bool} {proofs : Fin L → G₁} (hsrs : srs = Groups.PowerSrs.generate (g₁ := g₁) (g₂ := g₂) n τ) (hgen : srs.1[0] ≠ 1) (hverify_all : ∀ i : Fin L, accepts i = true → KZG.verifyOpening (g₁ := g₁) (g₂ := g₂) (pairing := pairing) srs.2 cm (proofs i) (queryOf i) (responseOf i)) (hFBcond : functionBindingCondExt n L (τ, srs, cm, queryOf, responseOf, accepts, proofs)) {A S : Finset (Fin L)} (hqueryS : Set.InjOn queryOf ↑S) (hresS : findS n A cm srs queryOf responseOf = some S) (hfs_none : List.findSome? (fun i ↦ if srs.1[0] ^ (queryOf i).val = srs.1[1]'(Nat.lt_add_of_pos_left hn) then some (queryOf i) else none) (List.finRange L) = none) : Groups.arsdhCondition n (τ, (interpolationArsdhOutput (p := p) (G₂ := G₂) S ({ srs := srs, cm := cm, queryOf := queryOf, responseOf := responseOf, accepts := accepts, proofs := proofs } : FunctionBindingExtTranscript (p := p) n L G₁ G₂)).toTuple) := by simp only [interpolationArsdhOutput, FunctionBindingArsdhOutput.toTuple, Groups.arsdhCondition, ne_eq, one_div] have hresS_symm : some S = findS n A cm srs queryOf responseOf := hresS.symm refine ⟨?_, ?_, ?_, ?_⟩ · rw [Finset.card_image_of_injOn hqueryS] exact find_s_card n cm A S srs queryOf responseOf hresS_symm · have hτneq_all : ∀ i : Fin L, queryOf i ≠ τ := query_ne_tau_of_find_query_with_srs_power_none (g₁ := g₁) hn τ srs queryOf hsrs hfs_none have hτ_not_image : τ ∉ S.image queryOf := by simp only [Finset.mem_image, not_exists, not_and] intro i _ exact hτneq_all i exact prod_x_sub_c_eval_ne_zero hτ_not_image · intro hdiv have hcm_eq_c' : cm = commit srs.1 ((CLagrange.interpolate S queryOf responseOf).val.coeff ∘ Fin.val) := div_eq_one.mp hdiv exact (find_s_diverges n cm A S queryOf responseOf srs hresS_symm) hcm_eq_c'.symm · have hcard : S.card = n + 1 := find_s_card n cm A S srs queryOf responseOf hresS_symm have hdeg : (CLagrange.interpolate S queryOf responseOf).degree ≤ (n : WithBot ℕ) := by exact interp_degree_le_of_card S queryOf responseOf hqueryS hcard have hS_ne : S.Nonempty := by rw [← Finset.card_pos, hcard]; exact Nat.succ_pos _ have hτneq : ∀ i ∈ S, queryOf i ≠ τ := by intro i _ exact query_ne_tau_of_find_query_with_srs_power_none (g₁ := g₁) hn τ srs queryOf hsrs hfs_none i have hVer : ∀ i ∈ S, KZG.verifyOpening (g₁ := g₁) (g₂ := g₂) (pairing := pairing) srs.2 cm (proofs i) (queryOf i) (responseOf i) := by intro i _ exact hverify_all i (hFBcond.1 i (Finset.mem_univ _)) have key := h1_zs_eq_h2_prime (g₁ := g₁) (g₂ := g₂) (pairing := pairing) n τ cm S queryOf responseOf proofs srs hn hsrs hτneq hVer hgen hpair hdeg hS_ne hqueryS simpa only [one_div] using key- Project
- ArkLib
- License
- Apache-2.0
- Commit
- fad5cbf80877
- Source
- ArkLib/Commitments/Functional/KZG/FunctionBinding/DegreeConflict.lean:826-885
Reuse this declaration
Bring the exact result into your workflow
The import identifies the source module. Your project still needs the pinned package dependency shown on this page.
What this badge means
This completion status comes from the project or community source. It has not yet been represented here as an independent rebuild and axiom audit.
Continue in this project
Related declarations
Affine gaps lifted to interleaved codes
affine_gaps_lifted_to_interleaved_codes
Project documentation
This lemma proves the final algebraic step in the DG25 Theorem 3.1 proof. It shows that if R > e + 1, then e * (R / (R - 1)) < e + 1. The intuition is that the fraction R / (R - 1) is always greater than 1, but as R gets larger, it gets closer to 1. The hypothesis R > e + 1 provides a strong enough bound to ensure the product e * (fraction) do...
Source project: ArkLib
Person-level attribution pending.
Gadget Decompose coeff
ArkLib.Lattices.Ajtai.gadgetDecompose_coeff
Plain-language statement
The k-th coefficient (k < deg φ) of a gadget-decomposition block is exactly the corresponding digit of the corresponding input coefficient.
Source project: ArkLib
Person-level attribution pending.
Gadget Decompose lawful
ArkLib.Lattices.Ajtai.gadgetDecompose_lawful
Plain-language statement
The base-b gadget decomposition is a lawful gadget decomposition.
Source project: ArkLib
Person-level attribution pending.