Methods and apparatus relating to cryptographic protection of memory attached over interconnects are described. In an embodiment, memory stores data and a processor having execution circuitry executes an instruction to program an inline memory expansion logic and a host memory encryption logic with one or more cryptographic keys. The inline memory expansion logic encrypts the data to be written to the memory and decrypts encrypted data to be read from the memory. The memory is coupled to the processor via an interconnect endpoint of a system fabric. Other embodiments are also disclosed and claimed.