Iranian Society of Cryptology The ISC International Journal of Information Security 2008-2045 Articles in Press 2026 02 12 An Efficient ECC-Based Multi-Server Authentication Scheme for 5G Environment without Online Registration Server 240528 10.22042/isecure.2026.240528 EN Seyede Marzieh Sadat Madani Faculty of Computer Engineering, University of Isfahan, Isfahan, Iran. Hamid Mala Faculty of Computer Engineering, University of Isfahan, Isfahan, Iran. 0000-0002-7789-452X Mehrad Jaberi Faculty of Computer Engineering, University of Isfahan, Isfahan, Iran. Journal Article Multi-Server Authentication and Key Agreement (MAKA) protocols in 5G networks play a pivotal role in securing communications due to their widespread applications in domains such as drones, cellular networks, and secure communications. We propose a novel and efficient protocol for multi-server authentication and key agreement in 5G networks, based on Elliptic Curve Cryptography (ECC). The proposed protocol is secure against attacks such as user and server impersonation, password guessing, insider attacks, tracking, session key disclosure, replay, denial-of-service, and man-in-the-middle attacks. Additionally, distinctive features such as user anonymity, avoidance of bilinear pairing, key confirmation, perfect forward secrecy, and the ability to perform authentication without an online registration server make the proposed scheme more efficient and secure, compared to previous schemes. Formal analysis using Proverif cryptographic protocol verifier, confirms the protocol’s confidentiality and authentication properties, while its computational and communication efficiency demonstrates relative superiority over comparable schemes.  https://www.isecure-journal.com/article_240528_20cc4ad06253459dbd29b2320eb02d64.pdf