A key-caching system retrieves actively used keys from a relatively fast cache memory for fast processing of wireless communications. Additional keys are stored in relatively slow system memory that has high storage capacity. As keys become needed for active use, the keys are retrieved from the system memory and stored in the cache memory. By using active memory for keys actively being used, system performance is enhanced. By using system memory for keys not being used, a greater number of keys are available for transfer to the cache and subsequent active use.