Abstract: Systems and techniques are provided for identity impersonation in access control systems. For example, a process for identity impersonation in access control systems can include: receiving, at a hardware identity impersonator from a first access domain, a request to make a target region accessible to a second access domain; updating a second access domain identity data structure to include an entry corresponding to the first access domain, the entry comprising an address of the target region and a first access domain identifier; receiving, at the hardware identity impersonator from the second access domain, an access request to access the target region, wherein the access request comprises an address and a second access domain identifier of the second access domain; and transmitting, at the hardware identity impersonator based on the access request, the address and the first access domain identifier to a memory management unit (MMU) of an access control system.