Tap-domain secret-key generation

A method for wireless communication at a first wireless device, comprising:

• transmitting, to a second wireless device, one or more reference signals over a channel between the first wireless device and the second wireless device;
• performing channel estimation for the channel based at least in part on the one or more reference signals, wherein a plurality of taps associated with the channel are determined based at least in part on the channel estimation;
• transmitting a first message to the second wireless device indicating one or more taps to be selected from the plurality of taps to obtain a secret key for encrypting a second message, wherein each tap of the plurality of taps corresponds to a different path between the first wireless device and the second wireless device;
• and
• communicating signaling with the second wireless device, the signaling comprising the second message that is encrypted with the secret key.

An apparatus for wireless communication at a first wireless device, comprising:

• a processor,
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• receive, from a second wireless device, one or more reference signals over a channel between the first wireless device and the second wireless device;
• perform channel estimation for the channel based at least in part on the one or more reference signals, wherein a plurality of taps associated with the channel are determined based at least in part on the channel estimation;
• receive a first message from the second wireless device indicating one or more taps to be selected from the plurality of taps to obtain a secret key for encrypting a second message, wherein each tap of the plurality of taps corresponds to a different path between the first wireless device and the second wireless device;
• and
• communicate signaling with the second wireless device, the signaling comprising the second message that is encrypted with the secret key.

An apparatus for wireless communication at a first wireless device, comprising:

• a processor;
• memory coupled with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• transmit, to a second wireless device, one or more reference signals over a channel between the first wireless device and the second wireless device;
• perform channel estimation for the channel based at least in part on the one or more reference signals, wherein a plurality of taps associated with the channel are determined based at least in part on the channel estimation;
• transmit a first message to the second wireless device indicating one or more taps to be selected from the plurality of taps to obtain a secret key for encrypting a second message, wherein each tap of the plurality of taps corresponds to a different path between the first wireless device and the second wireless device;
• and
• communicate signaling with the second wireless device, the signaling comprising the second message that is encrypted with the secret key.