Remote attestation method and device for composite device

A remote attestation device comprising:

• a first communications interface;
• and
• one or more processors coupled to the first communications interface and configured to:
• receive, from a first communication entity of a composite device and using the first communications interface, a first message carrying a first attestation result of first trustworthiness attestation on a second communication entity of the composite device, wherein the a first communication entity is a leader unit comprising a second communications interface configured to directly communicate with an external device, wherein the second communication entity does not comprise any communications interface configured to directly communicate with the external device, and wherein the composite device comprises a router, a switch, or a packet transport network (PTN) device;
• and
• obtain the first attestation result from the first message.

A first communication entity in a composite device and comprising:

• a memory configured to store instructions;
• a communications interface configured to directly communicate with an external device;
• and
• one or more processors coupled to the memory and the communications interface, wherein the instructions cause the one or more processors to be configured to:
• obtain first measurement information of a second communication entity of the composite device, wherein the second communication entity does not comprise any communications interface configured to directly communicate with the external device, wherein the first communication entity comprises a leader unit in the composite device, and wherein the composite device comprises a router, a switch, or a packet transport network (PTN) device;
• perform, based on the first measurement information, trustworthiness attestation on the second communication entity to obtain an attestation result;
• and
• send the attestation result to a remote attestation device.