Optimal Memory-Rate Tradeoff for Secure Multi-Access Coded Caching: The Case of Largest Access Number
Han Fang, Qian Nan Lu, Nan Liu, Wei Kang · 2024
This work addresses the secure multi-access coded caching (SMACC) problem involving$N$files,$K$users, and$K$caches, where each user can access$L$consecutive caches in a cyclic wrap-around manner. It is required that no user can obtain any information about the files other than the requested one. The optimal memory-rate tradeoff for the largest access number, i.e.,$L=K-1$, is found for the case of an arbitrary number of users and files. This is done by proposing two new optimal achievability schemes and providing tight converse results. As a special case, the optimal memory-rate tradeoff for the secure coded caching (SCC) problem [1] in the two-user case has been found.