Skip to content
Static snapshot of QMint (git 5b73a0bb93c1) — live experiments run locally
Research library

Proof obligation · P-S1

KLPR2022 Lemma 1, Eq. (1) (main text p.5; proof SI Note IV)

s_money_kent_2022_ideal_2site · A. Kent, D. Lowndes, D. Pitalua-Garcia, J. Rarity. Practical quantum tokens without quantum memories and experimental tests. npj Quantum Information 8, 28 (2022). doi:10.1038/s41534-022-00524-4

Status
PUBLISHED REPRODUCEDLane D reproduced the published bound in code with an independent check.
Game
S1
Anchor
KLPR2022 Lemma 1, Eq. (1)
Source file
proofs/OBLIGATIONS.yaml

Source and theorem

KLPR2022 Lemma 1, Eq. (1) (main text p.5; proof SI Note IV): IQT1 and IQT2 are eps_unf-unforgeable with eps_unf = (1/2 + 1/(2*sqrt(2)))^N.

Citations

Record

Every field of the source record, in file order.

Protocolprotocol

s_money_kent_2022_ideal_2site

Gamegame

S1

Sourcesource

KLPR2022

Assumptionsassumptions
  • Ideal schemes IQT1/IQT2 of Table 1: N exact BB84 qubits with uniformly random states and bases; no loss, no preparation/measurement error, no multiphoton component.
  • Exactly two presentation points (M = 1).
  • Bob (the bank) follows the scheme honestly; Bob's agents communicate over secure authenticated channels; Alice is arbitrary (unforgeability quantifies over dishonest Alice).
Required declarationsrequired_declarations
  • ideal_no_loss_no_error
  • two_presentation_points
  • honest_bank_secure_agent_channels
  • uniform_bb84_states_and_bases
Finite n or asymptoticfinite_n_or_asymptotic

exact upper bound for every finite N >= 1

Parametersparameters
N: number of transmitted qubits, integer >= 1
M: presentation-point pairs; the ideal bound is stated for M = 1 only (optional, default 1)
Quantifier over adversariesquantifier_over_adversaries

for every (unbounded quantum) strategy of dishonest Alice, P[Bob accepts at both presentation points] <= eps_unf

Mathematical boundmathematical_bound

(1/2 + 1/(2 sqrt 2))^N

Numerical methodnumerical_method

log-space

Verification scriptverification_script

qmint/proofs/ideal_bounds.py

Independent crosscheckindependent_crosscheck

qmint/proofs/checker.py

Caveatscaveats
  • Not Wiesner's 3/4 bound. Not valid for the realistic schemes QT1/QT2 (use P-S2). No multi-site (M>1) version is stated for the IDEAL schemes; Theorem 2 concerns QT^M only.
  • Privacy of IQT is argued in prose only (main text p.4); no numbered privacy lemma for IQT, so the evaluator returns no privacy value for S1.
Statusstatus

PUBLISHED_REPRODUCED

Boundsbounds
- bound_id: P-S1/unf
  axis: epsilon_unf
  anchor: KLPR2022 Lemma 1, Eq. (1)
  formula: (1/2 + 1/(2 sqrt 2))^N
  domain: N integer >= 1, M = 1
  monotonicity: {}

Related entries