{'fraction_non_alphanumeric': 0.011890606420927468, 'fraction_numerical': 0.0, 'mean_word_length': 5.101449275362318, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
An improved secure and efficient group key agreement scheme in VANETs

VANET is a wireless mobile network that can provide communication for vehicles and roadside units. The security and efficiency of its key agreement scheme are critical. After analyzing the security defects of the VANET key agreement scheme of Liu et al., an improved secure and efficient group key agreement scheme in VANETs is proposed in this paper. We construct a group key agreement scheme replacing the bilinear pair with elliptic curve cryptography, which can achieve a higher level of security. A strict security analysis is given to prove that the scheme meets various security requirements of VANETs. Compared with similar schemes, the performance analysis shows that the computation cost and communication cost of the proposed scheme are significantly reduced.