A theoretical quantum key distribution scheme using Einstein-Podolsky-Rosen (EPR) pairs is presented. This scheme is efficient in that it uses all EPR pairs in distributing the key except those chosen for checking eavesdroppers. The high capacity is achieved because each EPR pair carries 2 bits of key code.
A novel secure quantum key distribution scheme using EPR pairs is presented. It has three distinct features: 1) it is very efficient. Unlike existing quantum key distribution schemes, this scheme uses all EPR pairs in distributing the key except those chosen for checking eavesdroppers; 2) this protocol has high capacity because each EPR pair carries 2 bits of key code while existing schemes carry only one bit of key code; 3) this scheme can be used for distributing a common key among arbitrary number of parties.
Entanglement swapping between Einstein-Podolsky-Rosen (EPR) pairs can be used to generate the same sequence of random bits in two remote places. A quantum key distribution protocol based on this idea is described. The scheme exhibits the following features. (a) It does not require that Alice and Bob choose between alternative measurements, therefore improving the rate of generated bits by transmitted qubit. (b) It allows Alice and Bob to generate a key of arbitrary length using a single quantum system (three EPR pairs), instead of a long sequence of them. (c) Detecting Eve requires the comparison of fewer bits. (d) Entanglement is an essential ingredient. The scheme assumes reliable measurements of the Bell operator.