Talk:Quantum money

another drawback?

I only have a moderate understanding on this. But it seems to me that a counterfitter could just measure 1 bank note's polarizations and then make ~10 copies of that note with the same polarizations that were measured. With very advanced machinery, this could probably be automated. And I don't think every person would be able to verify a bill before accepting it. If the bills qubits are destroyed on reading, they could probably be reprogrammed to the read values. If not, they could be given to beggers while the counterfitter takes the other ten copies and uses them at different merchants.198.232.211.130 (talk) 21:01, 27 June 2011 (UTC)

Where is the dispute?

Seems the previous commenter is confused about the quantum nature of photon polarisation. In fact, the polarisation of a single photon cannot be perfectly measured without knowing the basis. More information can be found in http://en.wikipedia.org/wiki/Qubit. — Preceding unsigned comment added by 142.1.219.240 (talk) 22:29, 9 June 2014 (UTC)

About neutrality

In Peter Shor's presentation about quantum money, he indeed refers to Stephen Wiesner's contribution: "Two of the first two quantum cryptographic protocols were Wiesner’s protocol for quantum money, and the BB84 protocol for key exchange. Wiesner’s protocol for quantum money inspired BB84. Both of these depend on the quantum no-cloning theorem.". The original article of Wiesner is called "Conjugate coding". Chrisdecorte (talk) 16:37, 16 May 2015 (UTC)

3/4 probability

The article states:

"the would-be counterfeiter has a probability 3/4 of success in duplicating it correctly"

Shouldn't this be:

"the would-be counterfeiter has a probability 1/2 of success in duplicating it correctly and a probability 3/4 of the counterfeit being undetected"

Since there's a 50% chance you guess the right basis (correct duplication), and there's a 50% chance the bank measures the correct value even if it's in the wrong basis (50% + 50%*50% total)