Due to non-ideal conditions in the measurements of the wireless channel, high initial bit error rate (BER) in the preliminary key is resulted, which reduces the final secret key generation rate and even causes the secret key generation process fail. Aiming to resolve this problem, we first present and verify an optimal information reconciliation protocol; the validation experiment shows that not only the BER comes down more quickly, but also a higher information rate is achieved. Then, to address the problem of very high initial BER and further improve the efficiency of the secret key generation, we introduce the idea of pre-distillation into the secret key generation system, and present a pre-distillation method, which makes the initial BER comes down quickly, and ensures the subsequent information reconciliation be easily performed; hence the total key generation rate is improved. Experimental results demonstrate that the pre-distillation method has excellent ability of reducing the initial BER, especially in the case of very high initial BER. The combination of our proposed pre-distillation and our optimal information reconciliation is the most efficient one when the initial BER is larger than 0.15, and the information rate is improved by more than forty-nine times when the initial BER is 0.3
Due to non-ideal conditions in the measurements of the wireless channel, high initial bit error rate (BER) in the preliminary key is resulted, which reduces the final secret key generation rate and even causes the secret key generation process fail. Aiming to resolve this problem, we first present and verify an optimal information reconciliation protocol; the validation experiment shows that not only the BER comes down more quickly, but also a higher information rate is achieved. Then, to address the problem of very high initial BER and further improve the efficiency of the secret key generation, we introduce the idea of pre-distillation into the secret key generation system, and present a pre-distillation method, which makes the initial BER comes down quickly, and ensures the subsequent information reconciliation be easily performed; hence the total key generation rate is improved. Experimental results demonstrate that the pre-distillation method has excellent ability of reducing the initial BER, especially in the case of very high initial BER. The combination of our proposed pre-distillation and our optimal information reconciliation is the most efficient one when the initial BER is larger than 0.15, and the information rate is improved by more than forty-nine times when the initial BER is 0.3
Due to non-ideal conditions in the measurements of the channel, high initial bit mismatch rate in the secret key generation is resulted, which reduces the final secret key generation rate and even causes the secret key generation process to fail. Aiming at this problem, a pre-process method that makes the initial bit mismatch rate come down quickly is proposed in this paper. Simulation results show that the new pre-process method has excellent ability of reducing the initial b it mismatch rate, especially in the case of very high initial bit mismatch rate. The data remaining rate is improved by more than thirty-seven times when the initial bit mismatch rate is 0.3.
Wireless networks are vulnerable to various attacks due to their open nature, making them susceptible to eavesdropping and other security threats. Eavesdropping attack takes place at the physical layer. Traditional wireless network security relies on cryptographic techniques to secure data transmissions. However, these techniques may not be suitable for all scenarios, especially in resource-constrained environments such as wireless sensor networks and adhoc networks. In these networks having limited power resources, generating cryptographic keys between mobile entities can be challenging. Also, the cryptographic keys are computationally complex and require key management infrastructure. Physical Layer Key Generation (PLKG) is an emerging solution to address these challenges. It establishes secure communication between two users by taking advantage of the wireless channel's inherent features. PLKG process involves channel probing, quantization, information reconciliation (IR) and privacy amplification to generate symmetric secret key. The researchers have used various PLKG techniques to get the secret key, sTop of Form till they face problems in the IR scheme to obtain symmetric keys between the users who share the same channel for communication. Both the code based and protocol based methods proposed in the literature have advantages and limitations related to their performance parameters such as information leakage, interaction delay and computation complexity. This research work proposes a novel IR mechanism that combines the protocol and code-based error correction methods to obtain reduced Bit Mismatch Rate (BMR), reduced information leakage, reduced interaction delay, and reduced computational time to enhance physical layer secret key's quality. In the proposed research work, the channel samples are generated using the Received Signal Strength (RSS) and Channel Impulse Response (CIR) parameters. These samples are quantized using Vector Quantization with Affinity Propagation Clustering (VQAPC) method to generate the preliminary key. The samples collected by the two users who wish to communicate, (for example Alice and Bob) will be different due to noise in the channel and hardware limitations. Hence their preliminary keys will be different. Removing this discrepancy between Bob's and Alice's initial keys, using novel Hybrid Protocol and Code related Information Reconciliation (HPC-IR) scheme to generate error corrected key, is the most important contribution of this research work. This key is further encoded by the MD5 hash function to generate a final secret key for exchanging information between two users over the wireless channel. It is observed that the proposed HPC-IR scheme achieves BMR of 19.4%, information leakage is 0.002, interaction delay is 0.001 seconds and computation time is 0.02 seconds.
In data post-processing for quantum key distribution, it is essential to have a highly efficient error reconciliation protocol. Based on the key redistribution scheme, we analyze a one-way error reconciliation protocol by data simulation. The relationship between the error correction capability and the key generation efficiency of three kinds of Hamming code are demonstrated. The simulation results indicate that when the initial error rates are(0,1.5%],(1.5,4%], and(4,11%], using the Hamming(31,26),(15,11), and(7,4) codes to correct the error, respectively, the key generation rate will be maximized. Based on this, we propose a modified one-way error reconciliation protocol which employs a mixed Hamming code concatenation scheme. The error correction capability and key generation rate are verified through data simulation. Using the parameters of the posterior distribution based on the tested data, a simple method for estimating the bit error rate(BER) with a given confidence interval is estimated. The simulation results show that when the initial bit error rate is 10.00%, after 7 rounds of error correction, the error bits are eliminated completely, and the key generation rate is 10.36%; the BER expectation is 2.96×10-10, and when the confidence is 95% the corresponding BER upper limit is 2.17×10-9. By comparison, for the single(7,4) Hamming code error reconciliation scheme at a confidence of 95%,the key generation rate is only 6.09%, while the BER expectation is 5.92×10-9, with a BER upper limit of 4.34×10-8. Hence, our improved protocol is much better than the original one.
In data post-processing for quantum key distribution, it is essential to have a highly efficient error reconciliation protocol. Based on the key redistribution scheme, we analyze a one-way error reconciliation protocol by data simulation. The relationship between the error correction capability and the key generation efficiency of three kinds of Hamming code are demonstrated. The simulation results indicate that when the initial error rates are (0,1.5%], (1.5,4%], and (4,11%], using the Hamming (31,26), (15,11), and (7,4) codes to correct the error, respectively, the key generation rate will be maximized. Based on this, we propose a modified one-way error reconciliation protocol which employs a mixed Hamming code concatenation scheme. The error correction capability and key generation rate are verified through data simulation. Using the parameters of the posterior distribution based on the tested data, a simple method for estimating the bit error rate (BER) with a given confidence interval is estimated. The simulation results show that when the initial bit error rate is 10.00%, after 7 rounds of error correction, the error bits are eliminated completely, and the key generation rate is 10.36%; the BER expectation is 2.96 × 10-10, and when the confidence is 95% the corresponding BER upper limit is 2.17 × 10-9. By comparison, for the single (7,4) Hamming code error reconciliation scheme at a confidence of 95%, the key generation rate is only 6.09%, while the BER expectation is 5.92 × 10-9, with a BER upper limit of 4.34 × 10-8. Hence, our improved protocol is much better than the original one.
In data post-processing for quantum key distribution, it is essential to have a highly efficient error reconciliation protocol. Based on the key redistribution scheme, we analyze a one-way error reconciliation protocol by data simulation. The relationship between the error correction capability and the key generation efficiency of three kinds of Hamming code are demonstrated. The simulation results indicate that when the initial error rates are(0,1.5%],(1.5,4%], and(4,11%], using the Hamming(31,26),(15,11), and(7,4) codes to correct the error, respectively, the key generation rate will be maximized. Based on this, we propose a modified one-way error reconciliation protocol which employs a mixed Hamming code concatenation scheme. The error correction capability and key generation rate are verified through data simulation. Using the parameters of the posterior distribution based on the tested data, a simple method for estimating the bit error rate(BER) with a given confidence interval is estimated. The simulation results show that when the initial bit error rate is 10.00%, after 7 rounds of error correction, the error bits are eliminated completely, and the key generation rate is 10.36%; the BER expectation is 2.96×10-10, and when the confidence is 95% the corresponding BER upper limit is 2.17×10-9. By comparison, for the single(7,4) Hamming code error reconciliation scheme at a confidence of 95%,the key generation rate is only 6.09%, while the BER expectation is 5.92×10-9, with a BER upper limit of 4.34×10-8. Hence, our improved protocol is much better than the original one.
We propose an improved method of secret key generation using the variations in wireless channel. We construct reciprocal channel profiles at a pair of transceivers and enhance it using the l 1 -norm minimization technique. Thereafter preliminary keys are obtained that are synchronized by a localized information reconciliation technique. The privacy of the synchronized keys is enhanced by generating secure hashes. We implement the proposed method on a testbed and validate its performance to show decreased rates of bit disagreement of preliminary keys, at an increased key generation rate.