All proofs
Project-declaredLean 4.32.0 · mathlib@81a5d257

Sign uses At Most Rho Card Omega Queries

Fischlin.sign_usesAtMostRhoCardOmegaQueries

Plain-language statement

Fischlin signing makes at most ρ * |Ω| random-oracle queries under unit-cost instrumentation.

Exact Lean statement

theorem sign_usesAtMostRhoCardOmegaQueries
    (runtime : QueryImpl (fischlinROSpec Stmt Commit Chal Resp ρ b M) m)
    (pk : Stmt) (sk : Wit) (msg : M) :
    Queries[ (Fischlin σ hr ρ b S M).sign pk sk msg in runtime ] ≤ ρ * FinEnum.card Chal

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
theorem sign_usesAtMostRhoCardOmegaQueries    (runtime : QueryImpl (fischlinROSpec Stmt Commit Chal Resp ρ b M) m)    (pk : Stmt) (sk : Wit) (msg : M) :    Queries[ (Fischlin σ hr ρ b S M).sign pk sk msg in runtime ]  ρ * FinEnum.card Chal := by  classical  let _ : SampleableType Chal := inferInstance  let repStep : (Fin ρ  Commit × PrvState)  Fin ρ  AddWriterT  m (Commit × Chal × Resp) :=      fun commits i => do    let comVec : Fin ρ  Commit := fun j => (commits j).1    let comList := List.ofFn comVec    let sc_i := (commits i).2    let result       fischlinSearchAuxWithUnitCost σ        (runtime := runtime) (pk := pk) (sk := sk) (sc := sc_i) (msg := msg)        (comList := comList) (i := i)        (FinEnum.toList Chal) (none : Option (Chal × Resp × Fin (2 ^ b)))    match result with    | some (ω, resp) => pure (comVec i, ω, resp)    | none => pure (comVec i, default, default)  have hlen : (FinEnum.toList Chal).length = FinEnum.card Chal := by    simp [FinEnum.toList]  have hrep :  commits i,      AddWriterT.QueryBoundedAboveBy (repStep commits i) (FinEnum.card Chal) := by    intro commits i    let comVec : Fin ρ  Commit := fun j => (commits j).1    let comList := List.ofFn comVec    have hsearch :        AddWriterT.QueryBoundedAboveBy          (fischlinSearchAuxWithUnitCost σ            (runtime := runtime) (pk := pk) (sk := sk) (sc := (commits i).2)            (msg := msg) (comList := comList) (i := i)            (FinEnum.toList Chal) (none : Option (Chal × Resp × Fin (2 ^ b))))          (FinEnum.toList Chal).length := by      simpa using        (fischlinSearchAuxWithUnitCost_queryBoundedAboveBy          σ (runtime := runtime) (pk := pk) (sk := sk) (sc := (commits i).2)          (msg := msg) (comList := comList) (i := i)          (challenges := FinEnum.toList Chal) (best := none))    let finish : Option (Chal × Resp)  AddWriterT  m (Commit × Chal × Resp)      | some (ω, resp) => pure (comVec i, ω, resp)      | none => pure (comVec i, default, default)    have hcont :         result : Option (Chal × Resp), AddWriterT.QueryBoundedAboveBy (finish result) 0 := by      intro result      cases result with      | none =>          simpa [finish] using AddWriterT.queryBoundedAboveBy_pure            (m := m) ((comVec i, default, default) : Commit × Chal × Resp)      | some pair =>          rcases pair with ω, resp          simpa [finish] using AddWriterT.queryBoundedAboveBy_pure            (m := m) ((comVec i, ω, resp) : Commit × Chal × Resp)    exact AddWriterT.queryBoundedAboveBy_mono      (AddWriterT.queryBoundedAboveBy_bind (n₁ := (FinEnum.toList Chal).length) (n₂ := 0)        hsearch hcont)      (by simp [hlen])  let commitComp : AddWriterT  m (Fin ρ  Commit × PrvState) :=    Fin.mOfFn ρ fun _ => (liftM (σ.commit pk sk) : AddWriterT  m (Commit × PrvState))  have hcommit :      AddWriterT.QueryBoundedAboveBy commitComp 0 := by    have hstep :        AddWriterT.QueryBoundedAboveBy          (liftM (σ.commit pk sk) : AddWriterT  m (Commit × PrvState)) 0 := by      change AddWriterT.QueryBoundedAboveBy        (monadLift (monadLift (σ.commit pk sk) : m (Commit × PrvState)) :          AddWriterT  m (Commit × PrvState)) 0      exact AddWriterT.queryBoundedAboveBy_monadLift _    simpa [commitComp] using      (AddWriterT.queryBoundedAboveBy_fin_mOfFn (n := ρ) (k := 0)        (f := fun _ => (liftM (σ.commit pk sk) : AddWriterT  m (Commit × PrvState)))        (fun _ => hstep))  suffices      AddWriterT.QueryBoundedAboveBy        (commitComp >>= fun commits => Fin.mOfFn ρ (repStep commits))* FinEnum.card Chal) by    have hsign :        HasQuery.Program.withUnitCost          (fun [HasQuery (fischlinROSpec Stmt Commit Chal Resp ρ b M) (AddWriterT  m)] =>            (Fischlin (m := AddWriterT  m) σ hr ρ b S M).sign pk sk msg)          runtime =          (commitComp >>= fun commits => Fin.mOfFn ρ (repStep commits)) := by      simp only [Fischlin, HasQuery.Program.withUnitCost, repStep, commitComp]      refine congrArg        (fun k => commitComp >>= k) ?_      funext commits      refine congrArg        (fun f : Fin ρ  AddWriterT  m (Commit × Chal × Resp) => Fin.mOfFn ρ f) ?_      funext i      let comVec : Fin ρ  Commit := fun j => (commits j).1      let comList := List.ofFn comVec      let finish : AddWriterT  m (Option (Chal × Resp))           AddWriterT  m (Commit × Chal × Resp) := fun oa => do        let result  oa        match result with        | some (ω, resp) => pure (comVec i, ω, resp)        | none => pure (comVec i, default, default)      convert congrArg finish        (fischlinSearchAux_eq_withUnitCost          σ (runtime := runtime) (pk := pk) (sk := sk) (sc := (commits i).2)          (msg := msg) (comList := comList) (i := i)          (challenges := FinEnum.toList Chal) (best := none)) using 1;        rfl    simpa [HasQuery.UsesAtMostQueries, hsign] using this  simpa [Nat.zero_add] using    (AddWriterT.queryBoundedAboveBy_bind (n₁ := 0) (n₂ := ρ * FinEnum.card Chal) hcommit      (fun commits =>        AddWriterT.queryBoundedAboveBy_fin_mOfFn (n := ρ) (k := FinEnum.card Chal)          (fun i => hrep commits i)))
Project
VCVio
License
Apache-2.0
Commit
2ceb2d825ee3
Source
VCVio/CryptoFoundations/Fischlin/CostAccounting.lean:383-490

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

Project-declaredLean 4.32.0

Expected Cost Nat eq sum tail probs of pathwise Cost At Most

AddWriterT.expectedCostNat_eq_sum_tail_probs_of_pathwiseCostAtMost

Plain-language statement

Finite tail-sum formula for natural-valued writer cost under a pathwise upper bound. If every execution path of oa incurs cost at most n, then the tail probabilities vanish above n, so the infinite tail sum truncates to Finset.range n.

program verificationseparation logiccryptography

Source project: VCVio

Person-level attribution pending.

View proof record
Project-declaredLean 4.32.0

IND CPA advantage to Real le sum step signed Advantage Real abs

AsymmEncAlg.IND_CPA_advantage_toReal_le_sum_step_signedAdvantageReal_abs

Plain-language statement

Planned generic one-time-to-many-time lift: bounded multi-query IND-CPA advantage is at most the sum of the extracted one-time signed advantages over the first q fresh LR queries.

program verificationseparation logiccryptography

Source project: VCVio

Person-level attribution pending.

View proof record