The Bit Pair Iteration Protocol Sample Clauses

The Bit Pair Iteration Protocol. The bit pair iteration protocol is proposed by Xxxxxx et al. in [26] (see also [8]). It consists of a number of rounds and operates on the binary strings of Xxxxx and Xxx. In each round, Xxxxx and Xxx perform the following steps: They both divide their strings into pairs of bits. Round i: Xxxxx sends Bob the parity of each of her bit pairs over the public channel. Bob computes the parity bit of each of his bit pairs, and compares it to the parity bit received from Xxxxx. If the parities match, Bob announces OK on the public channel. The first bit of the pair is discarded to compensate for the information that leaked to Eve with the parity bit. The second bit of the pair is retained for the next round. If the parities differ, the bit pair is discarded entirely. The retained bits (those not discarded) are taken together and form the input bit string for the next round. In each round of the protocol, Xxxxx and Xxx accept a bit if and only if their parities for a pair of bits coincides with each other. In that case, the error pattern between the two pairs is either (0,0) or (1,1). It is easy to see that after round

The Bit Pair Iteration Protocol. When the optimal weight (block length) determined by the bit error probability is 2, our general protocol reduces to the bit pair iteration protocol as described in Section 2.2.3. Bob can determine the a posteriori probabilities for each of his bits with the BPD-algorithm, just as we did in the analysis of the bit pair iteration protocol in Section 2.2.3. On the other hand, when the bit error probability p between Xxxxx’s and Bob’s strings is smaller than 0.20, the optimal weight is larger than 2 and the bit pair iteration protocol is not the best choice any more. For the example of Subsection 2.5.6, our protocol can achieve a much larger information rate than the bit pair iteration protocol, as illustrated in Table 2.5. protocol β Rβ(0.05) bit pair iteration protocol (1 round) 0.002763 0.500 our protocol n =1000 0.002763 0.699 bit pair iteration protocol (2 round) 0.000008 0.249 our protocol n =1000 0.000008 0.613 Table 2.5: Comparison of our protocol and the bit pair iteration protocol