Explore a 14-minute conference talk from USENIX OSDI '21 that delves into scalable memory protection in the PENGLAI Enclave. Learn about innovative software-hardware co-design techniques addressing limitations in secure memory protection for cloud-based applications. Discover two new hardware primitives: Guarded Page Table (GPT) and Mountable Merkle Tree (MMT), which enable dynamic, fine-grained, and large-scale secure memory with fast initialization. Understand how these advancements support thousands of concurrent enclaves, improve resource utilization, and eliminate high-cost initialization using fork-style enclave creation. Examine the implementation results, including support for 1,000s of concurrent enclave instances, scalability up to 512GB secure memory, and significant performance improvements in memory initialization and real-world applications like MapReduce.