In massive machine-type communications (mMTC). user-specific and non-orthogonal signatures can be assigned to wireless devices for uplink grant-free access. In this paper. we analyze the performance of signature-based grant-free random access in the presence of an adversary. https://www.roneverhart.com/10-oz-Black-Thermal-Plastic-Molcajete-Bowl-5-1-4-x-5-1-4-x-2-1-2-1-count-box/