Prepare and Measure Quantum Digital Signature: Difference between revisions

# involves three parties (Seller, Buyer, Verifier) exchanging one-bit classical messages.

# assumes that all classical and quantum channels are [[authenticated]] (secure).

# assumes maximum number of participating parties are honest. In the present case at least two parties are honest.

# provides security against repudiation, i.e. the probability that seller succeeds in making buyer and seller disagree on the validity of her sent quantum signature decays exponentially with L, as stated by the formula <math>P(\text{rep})\le e^{-(s_v-s_a)^2L}</math>.

# provides security against forgery, i.e. any recipient (verifier) with high probability rejects any message which was not originally sent by the seller herself. Forging probability is given by the formula, <math>P(\text{forge})\le e^{-(c_{\min}-2s_v)^2L}</math>, where <math>c_{\min}</math> is 3/8 (calculated using uncertainty principle).