All proofs
Project-declaredLean 4.32.0 · mathlib@81a5d257

Prf implies uf cma

PRFScheme.prf_implies_uf_cma

Plain-language statement

Boneh-Shoup Theorem 6.2. PRF security implies UF-CMA security for the derived MAC: for any forger A, the constructed distinguisher macToPRFReduction prf A satisfies UF_CMA_Advantage(A) ≤ prfAdvantage(prf, B) + 1/|R|.

Exact Lean statement

theorem prf_implies_uf_cma [Nonempty R] [SampleableType R] [Fintype R]
    (prf : PRFScheme K D R) (adversary : (prf.toMacAlg).UF_CMA_Adversary) :
    (MacAlg.UF_CMA_Advantage ProbCompRuntime.probComp adversary).toReal ≤
      prf.prfAdvantage (macToPRFReduction prf adversary) +
        (Fintype.card R : ℝ)⁻¹

Formal artifact

Lean source

Canonical source
Full Lean sourceLean 4
theorem prf_implies_uf_cma [Nonempty R] [SampleableType R] [Fintype R]    (prf : PRFScheme K D R) (adversary : (prf.toMacAlg).UF_CMA_Adversary) :    (MacAlg.UF_CMA_Advantage ProbCompRuntime.probComp adversary).toReal       prf.prfAdvantage (macToPRFReduction prf adversary) +        (Fintype.card R : )⁻¹ := by  rw [ prfRealExp_macToPRFReduction_eq_UF_CMA_Exp prf adversary]  unfold prfAdvantage  set a := (Pr[= true | prf.prfRealExp (macToPRFReduction prf adversary)]).toReal  set b := (Pr[= true | prfIdealExp (macToPRFReduction prf adversary)]).toReal  linarith [le_abs_self (a - b), prfIdealExp_macToPRFReduction_le prf adversary]
Project
VCVio
License
Apache-2.0
Commit
2ceb2d825ee3
Source
VCVio/CryptoFoundations/MacFromPRF.lean:400-409

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