RoCE Express Internal Shared Memory  The 25GbE and 10GbE RoCE Express2.1 features use Remote Direct Memory Access  (RDMA) over Converged Ethernet (RoCE) to provide fast memory-to-memory  communications between two Z platforms. These features are designed to help reduce consumption of CPU resources for applications  that use the TCP/IP stack (such as IBM WebSpherefi that accesses an IBM Db2 database).  They can also help reduce network latency with memory-to-memory transfers by using  Shared Memory Communications over RDMA (SMC-R). With SMC-R, you can transfer huge amounts of data quickly and at low latency. SMC-R is  transparent to the application and requires no code changes, which enables rapid time to  value. Internal Shared Memory (ISM) is a virtual PCI network adapter that enables direct access to  shared virtual memory, providing a highly optimized network interconnect for Z platform  intra-communications. Shared Memory Communications-Direct Memory Access (SMC-D)  uses ISM. SMC-D optimizes operating systems communications in a way that is transparent  to socket applications. It also reduces the CPU cost of TCP/IP processing in the data path,  which enables highly efficient and application-transparent communications.  SMC-D requires no extra physical resources (such as RoCE Express features, PCIe  bandwidth, ports, I/O slots, network resources, or Ethernet switches). Instead, SMC-D uses  LPAR-to-LPAR communication through HiperSockets or an OSA-Express feature for  establishing the initial connection. z/OS and Linux on IBM Z support SMC-R and SMC-D. Now, data can be shared by way of  memory-to-memory transfer between z/OS and Linux on Z. For more information about the available network connectivity features, see 3.3, “Network  connectivity” on page 38. z15 provides two major groups of cryptographic functions: CPACF and Crypto-Express7S. CPACF is a high performance, low latency co-processor that performs symmetric key  encryption and calculates message digests (hashes) in hardware. The following algorithms  are supported: 1.2.4 Cryptography CPACF GLYPH<SM590000> AES GLYPH<SM590000> DES/TDES GLYPH<SM590000> SHA-1 GLYPH<SM590000> SHA-2 GLYPH<SM590000> SHA-3 GLYPH<SM590000> EdDSA (Ed448, Ed25519) GLYPH<SM590000> ECDSA (P-256, P-384, P-521) GLYPH<SM590000> ECDH (P-256, P-384, P521, X25519, X448) GLYPH<SM590000> Support for protected key signature creation. With z15, CPACF supports Elliptic Curve Cryptography clear key, improving the performance  of Elliptic Curve algorithms. The following algorithms are supported:  Chapter 1. Designed to take on today’s IT demands  13