en 5-Communication Systems Communication Systems Research Paper Research Paper <div style="text-align: justify;"><span style="font-family:Times New Roman;"><span style="font-size:14px;"><span style="color:#000000;">Shamir&rsquo;s secret sharing scheme is one of the substantial threshold primitives, based on which many security protocols are constructed such as group authentication schemes. Notwithstanding the unconditional security of Shamir&#39;s secret sharing scheme, protocols that are designed based on this scheme do not necessarily inherit this property. In this work, we evaluate the security of a lightweight group authentication scheme, introduced for IoT networks in IEEE IoT Journal in 2020, and prove its weakness against the linear subspace attack, which is a recently-proposed cryptanalytical method for secret sharing-based schemes. Then, we propose an efficient and attack-resistant group authentication protocol for IoT networks.</span></span></span></div> Group authentication,IoT Networks,Secret Sharing,Linear Subspace Attack,Lightweight 2520 2520 http://ijeee.iust.ac.ir/browse.php?a_code=A-10-4267-2&slc_lang=en&sid=1 A. Rezapour ali_rezapour@elec.iust.ac.ir 1800319475328460012103 1800319475328460012103 No Iran University of Science and Technology Z. Ahmadian zahraahmadian@yahoo.com 1800319475328460012104 0000000193564064 Yes Electrical Engineering Department, Shahid Beheshti University