“…Additionally, we assume that the length of an identity, a random number, a hash value, a timestamp, an elliptic curve point, the block size of AES symmetric encryption/decryption, and the modular exponentiation are 32 bits, 128 bits, 160 bits, 32 bits, 320 bits, 128 bits [55], and 1024 bits [14], respectively. The comprehensive study of the improved scheme and the related schemes [27,29,33,53,54] is given in Table 4. Furthermore, the performances of the sensor node are summarized in Table 5, because energy consumption is vital to evaluate the lifetime of the sensor node.…”