Techniques for securely communicating a data packet via at least one relay user equipment

A method of wireless communication at a relay user equipment (UE), comprising:

• receiving, from a first wireless device, an indication of a first data radio bearer (DRB) configuration for relaying, via a first portion of a data routing path, data between a second wireless device and the first wireless device and a second indication of a second DRB configuration for relaying, via a second portion of the data routing path, data between the second wireless de vice and the first wireless de vice;
• receiving, via the first portion of the data routing path and in accordance with the first DRB configuration, a data packet comprising a first message authentication code for the first portion of the data routing path and a second message authentication code for the second portion of the data routing path;
• determining, based at least in part on a first security key used to communicate with the second wireless device for which the relay UE is configured to relay data, that the second message authentication code was generated at least in part by the second wireless device;
• generating, based at least in part on the determination that the second message authentication code was generated at least in part by the second wireless device, a third message authentication code for the data packet based at least in part on a second security key used to communicate with the first wireless device;
• and
• transmitting the data packet to the first wireless device with at least an indication of the first message authentication code and the third message authentication code.

A first wireless device for wireless communication, comprising:

• a processor,
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the first wireless device to:
• generate a first message authentication code for a data packet based at least in part on a first security key used to communicate with a second wireless device via a first portion of a data routing path;
• generate a second message authentication code for the data packet based at least in part on a second security key used to communicate with a relay user equipment (UE) that is configured to relay data between the first wireless device and the second wireless device via a second portion of the data routing path, wherein the first portion of the data routing path is different from the second portion of the data routing path;
• determine a first data radio bearer (DRB) associated with a first DRB configuration for communicating with the relay UE via the second portion of the data routing path, wherein the first DRB configuration is different from a second DRB configuration for communicating with the second wireless device via the first portion of the data routing path;
• and
• transmit, via the second portion of the data routing path and in accordance with the first DRB configuration, the data packet to the relay UE, wherein the data packet comprises the first message authentication code for the first portion of the data routing path and the second message authentication code for the second portion of the data routing path.

A relay user equipment (UE) for wireless communication, comprising:

• a processor,
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the relay UE to:
• receive, from a first wireless device, an indication of a first data radio bearer (DRB) configuration for relaying, via a first portion of a data routing path, data between a second wireless device and the first wireless device and a second indication of a second DRB configuration for relaying, via a second portion of the data routing path, data between the second wireless device and the first wireless de vice;
• receive, via the first portion of the data routing path and in accordance with the first DRB configuration, a data packet comprising a first message authentication code for the first portion of the data routing path and a second message authentication code for the second portion of the data routing path;
• determine, based at least in part on a first security key used to communicate with the second wireless device for which the relay UE is configured to relay data, that the second message authentication code was generated at least in part by the second wireless device;
• generate, based at least in part on the determination that the second message authentication code was generated at least in part by the second wireless device, a third message authentication code for the data packet based at least in part on a second security key used to communicate with the first wireless device;
• and
• transmit the data packet to the first wireless device with at least an indication of the first message authentication code and the third message authentication code.