Authentication Network security 3 Communication wireless network 2 Communications networks 2 Computer crime 2 Cryptography 2 Cybe security for smart city 2 Cyber security 2 Cybersecurity 2 Information and Communication Technologies 2 Man in the middle 2 Man-in-the-middle attack 2 Network intrusion detection system 2 Network intrusion detection systems 2 Smart city 2 Smart meters 2 Smart phones 2 Smartphones 2 Wireless networks 2 communication wireless network 2 cyber security for smart cities 2 man-in-the-middle (MITM) attack 2 network intrusion detection system (NIDS) 2 smart city 2 'current 1 5G mobile communication systems 1 Block cipher algorithms 1 Blockchain 1 Centralised 1 Ciphertexts 1