Key establishment phase Sample Clauses

Key establishment phase. After a successful authentication phase, a shared symmetric key K on 16 bytes is established in order to secure the communication channel, such as in: 1 Case ‘not in the area’: the shared key is computed using a personalised function as: K = F(Enc(K1 K2, Xi)). First, the values K1 and K2 are computed by applying respectively an XOR of the nonce value N with the nonces S and W. Then, the concatenation of the two values K1 and K2 is done to apply an encryption with the associated secret key of the sensor node Xi. Thus, the key establishment phase terminates. 2 Else, case ‘in the area’: the shared key is computed using a personalised function. First, the concatenation of the nonce values N and M, and then apply an encryption with the associated secret key of the sensor node Xi as K = F(Enc(N M, Xi)). Consequently, the key establishment phase terminates. In this section, we provide in details the analysis of the proposed scheme in both of security and performance. First, we present a theoretical security analysis of the scheme concerning properties and resilience against different possible attacks. The security analysis is validated using an automated validation tool called AVISPA (xxxx://xxx.xxxxxx-xxxxxxx.xxx). Second, we evaluate and compare both communication and computational costs of the proposed scheme. In order to prove the energy saving of the scheme, we use energy models to estimate the energy cost consisting of both computational and communication costs.