Sidelink channel security
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may secure a communication for a physical sidelink channel using a secret key, such as a group common secret key or a UE-specific secret key. The UE may transmit the secured communication on the physical sidelink channel to a second UE. The second UE may extract the communication from the secured communication based at least in part on the secret key. Numerous other aspects are described.
1 . A first user equipment (UE) for wireless communication, comprising:
a memory; and
one or more processors, coupled to the memory, configured to:
secure, at a physical layer, a communication for a physical sidelink channel using a secret key; and
transmit the secured communication on the physical sidelink channel to a second UE.
2 . The UE of claim 1 , wherein the secret key is a group common key.
3 . The UE of claim 1 , wherein the secret key is a UE-specific key.
4 . The UE of claim 1 , wherein the one or more processors, to secure the communication, are configured to perform an XOR operation with an initialization value for the communication and the secret key.
5 . The UE of claim 1 , wherein the one or more processors, to secure the communication, are configured to add the secret key as a shift or decimal value to a data value of the communication and to a control value of the communication.
6 . The UE of claim 1 , wherein the one or more processors, to secure the communication, are configured to perform an XOR operation with a data value of the communication and the secret key or perform an XOR operation with a control value of the communication and the secret key.
7 . The UE of claim 1 , wherein the physical sidelink channel is a physical sidelink control channel.
8 . The UE of claim 1 , wherein the one or more processors, to secure the communication, are configured to:
determine a subset of frequency domain orthogonal cover code (FD-OCC) indices from among multiple FD-OCC indices based at least in part on the secret key; and
secure the communication by using an FD-OCC index that is in the subset of FD-OCC indices.
9 . The UE of claim 8 , wherein the one or more processors, to determine the subset, are configured to perform a modulo operation with the multiple FD-OCC indices and the secret key, or perform an XOR operation with the multiple FD-OCC indices and the secret key.
10 . The UE of claim 1 , wherein the communication includes sidelink control information 1 (SCI-1) or SCI-2.
11 . The UE of claim 10 , wherein the one or more processors, to secure the communication, are configured to scramble, remap, or perform an XOR operation on bits of the SCI-2 using the secret key.
12 . The UE of claim 10 , wherein the one or more processors, to secure the communication, are configured to secure a source identifier (ID) and a destination ID of the communication.
13 . The UE of claim 10 , wherein the one or more processors, to secure the communication, are configured to secure one or more of a redundancy version, a new data indicator, or a hybrid automatic repeat request process identifier.
14 . The UE of claim 1 , wherein the physical sidelink channel is a physical sidelink feedback channel (PSFCH).
15 . The UE of claim 14 , wherein the one or more processors are configured to use the secret key to determine a resource of a resource pool for the PSFCH.
16 . The UE of claim 15 , wherein the one or more processors, to use the secret key, are configured to use the secret key to randomize an index for the resource and perform a modulo operation with the index and a quantity of resources for the PSFCH.
17 . The UE of claim 15 , wherein the one or more processors, to secure the communication, are configured to perform an XOR operation with the secret key and one or more of a source identifier (ID), a destination ID, or a sum of the source ID and the destination ID.
18 . The UE of claim 1 , wherein the communication is for a sidelink synchronization signal for a physical sidelink broadcast channel.
19 . The UE of claim 1 , wherein the one or more processors, to secure the communication, are configured to shift a value of an acknowledgement or a negative acknowledgement based at least in part on the secret key.
20 . The UE of claim 1 , wherein the one or more processors, to secure the communication, are configured to swap a value of an acknowledgment with a value of a negative acknowledgement.
21 . The UE of claim 1 , wherein the one or more processors, to secure the communication, are configured to:
determine a subset of demodulation reference signal (DMRS) scrambling identifiers from among multiple DMRS scrambling identifiers based at least in part on the secret key; and
secure the communication by using a DMRS scrambling identifier that is in the subset of DMRS scrambling identifiers.
22 . The UE of claim 21 , wherein the one or more processors, to determine the subset, are configured to perform a modulo operation with the multiple DMRS scrambling identifiers and the secret key, or perform an XOR operation with the multiple DMRS scrambling identifiers and the secret key.
23 . The UE of claim 1 , wherein the one or more processors, to secure the communication, are configured to:
select a demodulation reference signal (DMRS) scrambling identifier based at least in part on the secret key; and
secure the communication by using the DMRS scrambling identifier.
24 . A second user equipment (UE) for wireless communication, comprising:
a memory; and
one or more processors, coupled to the memory, configured to:
receive, from a first UE, a secured communication for a sidelink channel that is secured with a secret key at a physical layer; and
extract a communication from the secured communication based at least in part on the secret key.
25 . The UE of claim 24 , wherein the secret key is a group common key or a UE-specific key.
26 . The UE of claim 24 , wherein the one or more processors, to extract the communication, are configured to perform an XOR operation with an initialization value for the secured communication and the secret key.
27 . The UE of claim 24 , wherein the one or more processors, to extract the communication, are configured to remove the secret key as a shift or decimal value from a data value of the secured communication and from a control value of the secured communication.
28 . The UE of claim 24 , wherein the one or more processors, to extract the communication, are configured to perform an XOR operation with a data value of the secured communication and the secret key or perform an XOR operation with a control value of the secured communication and the secret key.
29 . The UE of claim 24 , wherein the one or more processors, to secure the communication, are configured to descramble, remap, or perform an XOR operation on the secured communication using the secret key.
30 . A first user equipment (UE) for wireless communication, comprising:
a memory; and
one or more processors, coupled to the memory, configured to:
secure a communication for a physical sidelink channel using a secret key by at least one of:
determining a subset of frequency domain orthogonal cover code (FD-OCC) indices from among multiple FD-OCC indices based at least in part on the secret key, and securing the communication by using an FD-OCC index that is in the subset of FD-OCC indices;
shifting a value of an acknowledgement or a negative acknowledgement based at least in part on the secret key;
swapping a value of an acknowledgement with a value of a negative acknowledgement; or
selecting a DMRS scrambling identifier based at least in part on the secret key, and securing the communication by using the DMRS scrambling identifier; and
transmit the secured communication on the physical sidelink channel to a second UE.