In order to make the communication more secure in the dynamic environment, the signal strength is used through which high entropy bit can be achieved.The received signal strength is used to find the nearest node in order to forward the data towards the destination node.In the existing system the secret key is generated only by the source and the destination nodes.In our proposed system, the secret key is generated by each and every hop. The generated key is quantized by the technique called quantization and the bit mismatch is reduced by information reconciliation technique. The bits that are lost during information reconciliation is avoided by distillation. In order to reduce the resultant output bit stream, hash key of the secret key is generated by using Privacy amplification technique. The low output bit stream result in high entropy.Here the predictable key generation is highly reduced.In this we are generating the random number to ensure data integrity and authentication.For this MNF hash function is used which is of 256 bits Privacy amplification is used to ensure that the resultant bit pattern is random.The mismatched bits can also be identified easily.Multiple sensors are involved in increasing the rate of the secret key generation.Generated bit streams are verified by randomness test.Our experiment has been implemented in 802.11A laptops.
In order to make the communication more secure in the dynamic environment, the signal strength is used through which high entropy bit can be achieved.The received signal strength is used to find the nearest node in order to forward the data towards the destination node.In the existing system the secret key is generated only by the source and the destination nodes.In our proposed system, the secret key is generated by each and every hop. The generated key is quantized by the technique called quantization and the bit mismatch is reduced by information reconciliation technique. The bits that are lost during information reconciliation is avoided by distillation. In order to reduce the resultant output bit stream, hash key of the secret key is generated by using Privacy amplification technique. The low output bit stream result in high entropy.Here the predictable key generation is highly reduced.In this we are generating the random number to ensure data integrity and authentication.For this MNF hash function is used which is of 256 bits Privacy amplification is used to ensure that the resultant bit pattern is random.The mismatched bits can also be identified easily.Multiple sensors are involved in increasing the rate of the secret key generation.Generated bit streams are verified by randomness test.Our experiment has been implemented in 802.11A laptops.
In this paper, we evaluate the effectiveness of secret key extraction from the Received signal strength (RSS) variations on the wireless channel between the two devices for private communication between them. We use real world measurements of RSS in a variety of environments and settings. The results from our experiments with 802.11-based laptops show that 1)An adversary can cause predictable key generation in these static environments, and 2)In dynamic scenarios where the two devices are mobile, high entropy bits are obtained . Building on the strengths of existing secret key extraction approaches, we develop an environment adaptive secret key generation scheme that uses an adaptive Cascade-based information reconciliation and privacy amplification. In our scheme, to provide good scalability in terms of the number of nodes, we utilize a combinatorial design of public-private key pairs, which means nodes combine more than one key pair to encrypt and decrypt messages. We also show that it provides controllable resilience when malicious nodes compromise a limited number of nodes before key revocation and renewal.
We evaluate the effectiveness of secret key extraction, for private communication between two wireless devices, from the received signal strength (RSS) variations on the wireless channel between the two devices. We use real world measurements of RSS in a variety of environments and settings. Our experimental results show that (i) in certain environments, due to lack of variations in the wireless channel, the extracted bits have very low entropy making these bits unsuitable for a secret key, (ii) an adversary can cause predictable key generation in these static environments, and (iii) in dynamic scenarios where the two devices are mobile, and/or where there is a significant movement in the environment, high entropy bits are obtained fairly quickly. Building on the strengths of existing secret key extraction approaches, we develop an environment adaptive secret key generation scheme that uses an adaptive lossy quantizer in conjunction with Cascade-based information reconciliation [7] and privacy amplification [14]. Our measurements show that our scheme, in comparison to the existing ones that we evaluate, performs the best in terms of generating high entropy bits at a high bit rate. The secret key bit streams generated by our scheme also pass the randomness tests of the NIST test suite [21] that we conduct.
We evaluate the effectiveness of secret key extraction, for private communication between two wireless devices, from the received signal strength (RSS) variations on the wireless channel between the two devices. We use real world measurements of RSS in a variety of environments and settings. The results from our experiments with 802.11-based laptops show that in certain environments, due to lack of variations in the wireless channel, the extracted bits have very low entropy making these bits unsuitable for a secret key, an adversary can cause predictable key generation in these static environments, and in dynamic scenarios where the two devices are mobile, and/or where there is a significant movement in the environment, high entropy bits are obtained fairly quickly. Building on the strengths of existing secret key extraction approaches, we develop an environment adaptive secret key generation scheme that uses an adaptive lossy quantizer in conjunction with Cascade-based information reconciliation and privacy amplification. Our measurements show that our scheme, in comparison to the existing ones that we evaluate, performs the best in terms of generating high entropy bits at a high bit rate. The secret key bit streams generated by our scheme also pass the randomness tests of the NIST test suite that we conduct. We also build and evaluate the performance of secret key extraction using small, low-power, hand-held devices-Google Nexus One phones-that are equipped 802.11 wireless network cards. Last, we evaluate secret key extraction in a multiple input multiple output (MIMO)-like sensor network testbed that we create using multiple TelosB sensor nodes. We find that our MIMO-like sensor environment produces prohibitively high bit mismatch, which we address using an iterative distillation stage that we add to the key extraction process. Ultimately, we show that the secret key generation rate is increased when multiple sensors are involved in the key extraction process.
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.
This paper aims to develop and evaluate a lightweight and secure Secret Key Generation (SKG) system for static multi-user indoor wireless communication using Received Signal Strength Indicator (RSSI) data. The proposed system integrates fading interpolation, 5-bit multi-bit quantization, Cascade reconciliation, and SHA-128 hashing for privacy amplification. Experiments were conducted at5m,15m, and 25 m in a star topology with three legitimate users and one eavesdropper. At 5 m and 15 m, the system achieved high Key Generation Rates (KGR) of13.96%and14.52%, with Bit Mismatch Rates (BMR) of 86.73 % and 86.02 %. Cascade reconciliation retained up to 4120 bits from 5000-bit sequences, and SHA-128 ensured all keys were compressed to 128 -bit. NIST testing confirmed strong randomness (entropy 0.93) for legitimate users, while eavesdropper entropy remained low (0.81-0.84). AES-128 encryption successfully decrypted messages for valid pairs and failed for Eve, confirming system security. These results highlight the system's potential for secure and scalable communication in indoor IoT environments.
Secure key generation is one of the promising approach to establish secured link between two legitimate nodes for wireless communication. We established a system, which generate the secret key at the both end of the legitimate node. Secure key generation system contain four major block namely channel estimation, quantization, information reconciliation and privacy amplification, in which quantization is one of the important module. In secured key generation, output of the quantizer will affects the bit mismatch rate significantly. The present paper analyses different quantization schemes to make synchronization between two nodes. By applying key generation technique, we analyze effect of quantization bit on the key disagreement rate.