Are instantly confirmed decentralized transactions even theoretically possible?

[Come-from-Beyond]

just because entangled particles do things simultaneously does not mean in any way that 'quantum computing' will allow for instantaneous transmission of or processing of data, neither are possible

I didn't talk about entangled particles, that was quantum cryptography.

[Anmol_Verma]

We can not have instantly confirmed transactions because that will increase the risk of fraud.