A method of bridging communication between first and second buses (104, 110), comprising: storing address translation information and associated security indicators in a shared memory; using an egress circuit connected to the shared memory, in response to each first access request received from the first bus, each first access request including a first requester security indicator and a first address: rejecting the first access request in response to the first requester security indicator indicating a non-secure requester and the security indicator associated with the address translation information stored in the shared memory for the first address indicating a secure address range; and translating the first access request into a second access request for the second bus using the address translation information and communicating the second access request to the second bus, in response to the first requester security indicator indicating a secure requester; and using an ingress circuit connected to the shared memory, in response to each third access request received from the second bus and including a third address: translating the third access request into a fourth access request for the first bus using the address translation information stored in the shared memory; and communicating to the first bus the fourth access request and the security indicator stored in the shared memory that is associated with the address translation information for a fourth address. storing address translation information and associated security indicators in a shared memory; using an egress circuit connected to the shared memory, in response to each first access request received from the first bus, each first access request including a first requester security indicator and a first address: rejecting the first access request in response to the first requester security indicator indicating a non-secure requester and the security indicator associated with the address translation information stored in the shared memory for the first address indicating a secure address range; and translating the first access request into a second access request for the second bus using the address translation information and communicating the second access request to the second bus, in response to the first requester security indicator indicating a secure requester; and rejecting the first access request in response to the first requester security indicator indicating a non-secure requester and the security indicator associated with the address translation information stored in the shared memory for the first address indicating a secure address range; and translating the first access request into a second access request for the second bus using the address translation information and communicating the second access request to the second bus, in response to the first requester security indicator indicating a secure requester; and using an ingress circuit connected to the shared memory, in response to each third access request received from the second bus and including a third address: translating the third access request into a fourth access request for the first bus using the address translation information stored in the shared memory; and communicating to the first bus the fourth access request and the security indicator stored in the shared memory that is associated with the address translation information for a fourth address. translating the third access request into a fourth access request for the first bus using the address translation information stored in the shared memory; and communicating to the first bus the fourth access request and the security indicator stored in the shared memory that is associated with the address translation information for a fourth address.