Patent ID: 7757280

Claim:
A computer-implemented method for protecting a memory, said method comprising: responsive to a direct memory access (DMA) request received from a consumer for a transaction of data from an IO device to said memory, said request including an IO command and a capability (CAP), generating a cryptographically signed capability (CAPB); forming a credential from CAP and CAPB; appending said credential to said IO command; configuring said IO device according to said credential and said IO command; transmitting said data from said IO device to the memory; and prior to allowing execution of said DMA, authenticating that said credential is valid, wherein said step of authenticating further comprises: regenerating CAPB from a key available to an authenticating entity and from said CAP (included in CAPB); and verifying that the memory region information described in said cryptographically signed capability is the same as said requested region that was originally created, and that said cryptographically signed capability encompasses said IO command.