A computer-implemented method for secure communications between a host system and a data processing accelerator, the method comprising: establishing a secure connection between the host system and the data processing, DP, accelerator over a bus, the secure connection including a data channel; transmitting a first instruction from the host system to the DP accelerator over a command channel, the first instruction requesting the DP accelerator to perform a data preparation operation; characterized in that the method further comprises: receiving a first request to read a first data from a first memory location of the host system from the DP accelerator over the data channel, in response to the first instruction; examining the first request to determine whether the DP accelerator is entitled to read from the first memory location of the host system, wherein in response to the receiving the first request, the host system identifies the DP accelerator and the first memory location on the host system, and queries an access control list, ACL, map to determine whether the DP accelerator has access permission to the first memory location, wherein the ACL map contains a mapping table that maps different memory regions of a memory of the host system to DP accelerators; and allowing the DP accelerator to read from the first memory location, in response to determining that the DP accelerator is entitled to read from the first memory location; in response to the first request, transmitting the first data retrieved from the first memory location of the host system to the DP accelerator over the data channel, wherein the first data is utilized for a computation or a configuration operation; and transmitting a second instruction from the host system to the DP accelerator over the command channel, the second instruction requesting the DP accelerator to perform the computation or the configuration operation. establishing a secure connection between the host system and the data processing, DP, accelerator over a bus, the secure connection including a data channel; transmitting a first instruction from the host system to the DP accelerator over a command channel, the first instruction requesting the DP accelerator to perform a data preparation operation; characterized in that the method further comprises: receiving a first request to read a first data from a first memory location of the host system from the DP accelerator over the data channel, in response to the first instruction; examining the first request to determine whether the DP accelerator is entitled to read from the first memory location of the host system, wherein in response to the receiving the first request, the host system identifies the DP accelerator and the first memory location on the host system, and queries an access control list, ACL, map to determine whether the DP accelerator has access permission to the first memory location, wherein the ACL map contains a mapping table that maps different memory regions of a memory of the host system to DP accelerators; and allowing the DP accelerator to read from the first memory location, in response to determining that the DP accelerator is entitled to read from the first memory location; in response to the first request, transmitting the first data retrieved from the first memory location of the host system to the DP accelerator over the data channel, wherein the first data is utilized for a computation or a configuration operation; and transmitting a second instruction from the host system to the DP accelerator over the command channel, the second instruction requesting the DP accelerator to perform the computation or the configuration operation. receiving a first request to read a first data from a first memory location of the host system from the DP accelerator over the data channel, in response to the first instruction; examining the first request to determine whether the DP accelerator is entitled to read from the first memory location of the host system, wherein in response to the receiving the first request, the host system identifies the DP accelerator and the first memory location on the host system, and queries an access control list, ACL, map to determine whether the DP accelerator has access permission to the first memory location, wherein the ACL map contains a mapping table that maps different memory regions of a memory of the host system to DP accelerators; and allowing the DP accelerator to read from the first memory location, in response to determining that the DP accelerator is entitled to read from the first memory location; in response to the first request, transmitting the first data retrieved from the first memory location of the host system to the DP accelerator over the data channel, wherein the first data is utilized for a computation or a configuration operation; and transmitting a second instruction from the host system to the DP accelerator over the command channel, the second instruction requesting the DP accelerator to perform the computation or the configuration operation.