Unclonable encryption revisited (4 ˟ 2 = 8)
Unclonable Encryption is a technique similar to Quantum Key Distribution and authentication of quantum states; it quantum-protects classical ciphertext so that it cannot be copied by eavesdroppers. We propose an improved variant which has higher efficiency and much better noise tolerance. Our variant uses four cipherstate bases that are equally spaced on the Bloch sphere, instead of the usual + and × basis.