The SARG04 protocol does not differ much from the original BB84 protocol (Branciard et al.
Another way of protecting against photon number splitting attack is the use of decoy states QKD protocols, which are also advanced types of BB84 protocol (Brassard et al.
The Cerberis system uses AES (256-bits) for encryption and BB84 and SARG04 protocols for quantum key distribution.
We improve on this scheme by avoiding extra photon loss and extending the concept to the BB84 protocol.
In the BB84 protocol, there are two photon values for each measurement basis, therefore, there are a number of ways to implement DTBS schemes, (I) project the measurement bases into DTBs; (II) project the photon values into DTBs; and (III) project both measurement bases and photon values into DTBs.
The structure of a type I BB84 DTBS scheme is shown in Fig.
Detection values of type 1 DTBS BB84 scheme 1st DTB 2nd DTB DET 0 '0' (V/H basis) '0' (+/ - 45[degrees] basis) DET 1 '1' (V/H basis) '1' ( + /- 45[degrees] basis)
The structure of a type III BB84 DTBS scheme is shown in Fig.
In contrast to the BB84 protocol, which estimates a single error rate, two error rates [e.
2] are independent of the value of [alpha] and only depend on Eve's eavesdropping strategy, so the improved protocol is as secure as BB84 protocol.
In this section, we present simulation results of BB84 and its improved protocols that include comparing efficiency and security.
This means that any detectable eavesdropping in BB84 protocol is detectable in the improved protocol.