INTER-MESSAGE CERTIFICATE AND DIGEST ARRANGEMENTS IN WIRELESS COMMUNICATIONS SYSTEMS

Methods, systems, and devices for wireless communications are described. Aspects of the present disclosure provide techniques for inter-message certificate and digest arrangements in wireless communications systems. A first wireless device may transmit a message with a certificate, where subsequent messages include digests that correspond to the certificate. Digests may have a smaller data size than the certificate. A second wireless device may use a digest to identify a corresponding certificate transmitted in the message, and the second wireless device may use the certificate to verify that the first wireless device is the authorized transmitter of each message. In some examples, the message with the certificate may be an anchor message. In some examples, the message with the certificate may be an earliest message after an expiration or restart of a timer.

FIELD OF TECHNOLOGY

The following relates to wireless communications, including inter-message certificate and digest arrangements in wireless communications systems.

BACKGROUND

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support inter-message certificate and digest arrangements in wireless communications systems. Generally, the described techniques may enable devices to use certificates and digests across messages and message types in accordance with such inter-message certificate and digest arrangements. For example, a first wireless device may transmit a message including a certificate and subsequent messages including digests that correspond to the certificate. Digests may have a smaller payload size than a certificate (e.g., a digest may be a hash of the certificate). A receiving device may use a digest to identify the corresponding certificate. The receiving device may use the certificate to verify that the first wireless device is the authorized transmitter of each message. By communicating a message having a first message type to indicate a certificate, and then communicating one or more further messages having the same or different message type with a digest corresponding to the certificate, the system may realize improved communications efficiency, for example, while maintaining secure communications.

A method for wireless communication at a first wireless device is described. The method may include generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate, transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate, and transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message.

An apparatus for wireless communication at a first wireless device is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to generate, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate, transmit a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate, and transmit a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message.

Another apparatus for wireless communication at a first wireless device is described. The apparatus may include means for generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate, means for transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate, and means for transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message.

A non-transitory computer-readable medium storing code for wireless communication at a first wireless device is described. The code may include instructions executable by a processor to generate, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate, transmit a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate, and transmit a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying the first message as an anchor message of the set of messages based on a configuration of the first wireless device indicating that the anchor message corresponds to the first message type, where transmitting the first message including the certification may be based on the identifying.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for generating, subsequent to communicating the set of messages, a second certificate for authentication of a second set of messages and a second digest corresponding to the second certificate, transmitting a third message as a second anchor message of the second set of messages based on the third message having the first message type, the third message including the second certificate, and transmitting a fourth message of the second set of messages, the fourth message including the second digest corresponding to the second certificate.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for initiating a timer associated with a duration that the certification, the digest, or both may be valid, where transmitting the first message including the certificate may be based on initiating the timer.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first message may be an earliest message of the set of messages subsequent to initiating the timer.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for generating a second certificate for authentication of a second set of messages and a second digest corresponding to the second certificate based on restarting the timer, transmitting a third message of the second set of messages, the third message including the second certificate based on the third message being an earliest message of the second set of messages, where the third message includes the first message type or the second message type, and transmitting a fourth message including the second digest corresponding to the second certificate.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting a third message having a third message type to the second wireless device, the third message including the digest corresponding to the certificate of the first message having the first message type.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting an indication of an identifier of the first wireless device to at least the second wireless device, where transmitting the first message, the second message, or both may be based on the indication of the identifier.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for updating an identifier of the first wireless device based on an expiration of a timer associated with a duration that the identifier may be valid and transmitting a third message including a second certificate based on updating the identifier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, and the method, apparatuses, and non-transitory computer-readable medium may include further operations, features, means, or instructions for transmitting, in a duration between updating the identifier and transmitting the third message, one or more messages having different message types than the first message type associated with the anchor message, each of the one or more messages including the second certificate and transmitting a fourth message subsequent to the third message, the fourth message including a second digest corresponding to the second certificate.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for restarting a timer associated with a duration that the certification, the digest, or both may be valid based on updating the identifier, where transmitting the third message may be based on restarting the timer.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the third message includes an earliest message of a second set of messages associated with the second certificate, the third message having the first message type or the second message type.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the certificate may have a first data size larger than a second data size of the digest.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the digest includes a hash of the certificate.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the certificate may be associated with a set of multiple message types including the first message type and the second message type.

A method for wireless communication at a second wireless device is described. The method may include receiving a first message of a set of messages from a first wireless device, the first message having a first message type and including a certification for authentication of the set of messages, receiving a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type, and authenticating the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate.

An apparatus for wireless communication at a second wireless device is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive a first message of a set of messages from a first wireless device, the first message having a first message type and including a certification for authentication of the set of messages, receive a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type, and authenticate the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate.

Another apparatus for wireless communication at a second wireless device is described. The apparatus may include means for receiving a first message of a set of messages from a first wireless device, the first message having a first message type and including a certification for authentication of the set of messages, means for receiving a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type, and means for authenticating the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate.

A non-transitory computer-readable medium storing code for wireless communication at a second wireless device is described. The code may include instructions executable by a processor to receive a first message of a set of messages from a first wireless device, the first message having a first message type and including a certification for authentication of the set of messages, receive a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type, and authenticate the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, authenticating the identity of the first wireless device may include operations, features, means, or instructions for buffering the certificate in a memory of the second wireless device based on receiving the first message and linking the digest of the second message to the certificate of the first message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a third message having a third message type from the first wireless device, the third message including the digest corresponding to the certificate of the first message having the first message type and authenticating the first wireless device as the transmitter of the third message based on the digest of the third message and the certificate of the first message.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a third message including a second certificate for authentication of a second set of message, the third message having any message type of a set of multiple message types, receiving a fourth message including a second digest corresponding to the second certificate, the fourth message having any message type of the set of multiple message types, and authenticating the identity of the first wireless device as the transmitter of the third message and the fourth message based on the second certificate and the second digest.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving an indication of an identifier of the first wireless device, where authenticating the identity of the first wireless device as the transmitter of the set of messages may be based on the indication of the identifier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the certificate may have a first data size larger than a second data size of the digest.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the digest includes a hash of the certificate.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the certificate may be associated with a set of multiple message types including the first message type and the second message type.

DETAILED DESCRIPTION

Some wireless communications systems may support cryptographic techniques for secure communications. For example, devices may use a public key infrastructure (PKI) or other techniques for verification of identities in the system. As an illustrative example, a transmitting device may transmit a message to a receiving device, and the message may indicate a certificate corresponding to the transmitting device. A receiving device may use such a certificate to verify an identity or authorization of the transmitting device. However, in some examples such systems may experience relatively high signaling overhead. For example, the transmitting device may transmit separate certificates for different types of messages or there may be relatively long durations between messages of a message type. In such cases, certificates may be communicated relatively often, which may result in poor resource utilization, inefficient communications, or both.

In accordance with the techniques described herein, wireless devices may implement inter-message certificate and digest arrangements in wireless communications systems. For example, the described techniques may enable devices to use certificates and digests across messages and message types in accordance with such inter-message certificate and digest arrangements. For example, a first wireless device may transmit a message including a certificate and subsequent messages including digests that correspond to the certificate. Digests may have a smaller payload size than a certificate (e.g., a digest may be a hash of the certificate). A receiving device may use a digest to identify the corresponding certificate. The receiving device may use the certificate to verify that the first wireless device is the authorized transmitter of each message. By communicating a message having a first message type to indicate a certificate, and then communicating one or more further messages having the same or different message type with a digest corresponding to the certificate, the system may realize improved communications efficiency, for example, while maintaining secure communications.

In some examples, the techniques described herein may support an anchor-based arrangement for inter-message certificates and digests. For example, a first wireless device (e.g., the transmitting device) may generate or determine a certificate associated with the first wireless device. For example, the certificate may be an example of a digital identity of the first wireless device or may otherwise identify the first wireless device (e.g., for PKI, the certificate may be used to prove that the first wireless device has ownership of a public key for the first wireless device). The first wireless device may generate or determine a digest corresponding to the certificate. For example, the digest may be generated based on the certificate (e.g., a device may apply a hash or other function to the certificate to obtain the digest having a smaller data size than the certificate). The first wireless device may include the certificate as part of a first message having a first message type. For example, the first message may be an anchor message, where the anchor message includes the certificate and subsequent messages include digests corresponding to the certificate. As such, an anchor message may refer to any message or message type that includes a certificate or other authorization feature to which subsequent messages refer or correspond to (e.g., using a digest or the like). For example, a particulate message type may be configured as an anchor message type, and the first transmitted message of that message type may be referred to as the anchor message. In some such examples, the first message is an anchor message and may be of a first message type. The subsequent messages may be of any message type (e.g., a message type different than the first message type) based on the first message being an anchor message. That is, the messages including digests may be of any message type and include digests corresponding to the certificate included in the anchor message that has the first message type.

Additionally or alternatively, the techniques described herein may support a timer-based arrangement. For example, the first wireless device may use a timer corresponding to a duration that a certificate is valid (e.g., the first wireless device may initiate the timer based on generating the certificate). Upon an expiration of the timer, the certificate may be invalid. Thus, the first wireless device may generate another certificate and restart the timer. In some examples, the first wireless device may transmit a message including the certificate after initiating or restarting the timer. For example, the earliest message of a set of messages communicated while the timer is active may include the certificate, and messages subsequent to the earliest message may include a respective digest corresponding to the certificate. In some examples, any message type may include the certificate (e.g., the earliest message may be of any message type). In some examples of the various techniques described herein, a wireless device may update an identifier periodically. In some cases, the wireless device may include a certificate in each message between updating the identifier and sending an anchor message of the anchor message type. Additionally or alternatively, the wireless device may restart a timer, and the first message subsequent to restarting the timer may include a certificate.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to transmission timelines and a process flow. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to inter-message certificate and digest arrangements in wireless communications systems.

In some cases, the UE115may operate within a cellular-V2X (C-V2X) system. For example, the UE115may correspond to a vehicle, a UE115utilized by a pedestrian, one or more sensors within the C-V2X system, and the like. In some examples, the UE115may exchange messages with one or more other UEs115to enable safe vehicle operations in the presence of vulnerable road users (VRUs). In some examples, the UE115may securely exchange the aforementioned messages by utilizing one or more security measures (e.g., a PKI) to verify both transmissions and receptions corresponding to other UEs115, where a PKI certificate may be used to verify an authorization of each C-V2X message.

In some cases, however, a signaling overhead associated with the PKI certificates may be large. For example, a basic safety message (BSM) payload without a corresponding certificate may have a data size, as an example, of 100-200 bytes. However, the certificate itself may have a relatively large data size, such as more than 100 bytes. In such cases, the overhead associated with the certificate may be relatively high due to including the certificate in the message payload (e.g., the payload of the BSM with the certificate may be nearly twice as large). To save signaling overhead and communication bandwidth, the UE115may implement a digest as an abbreviated version of the certificate (e.g., hash) or any other type of identifier or payload that indicates the certificate. A digest may be generated using one or more algorithms (e.g., a hashing algorithm) where the size of the digest may be relatively small (e.g., 8 bytes). In some BSM designs, when a vehicle (e.g., UE115) receives a BSM with a full certificate, the vehicle may buffer the certificate in memory associated with the vehicle. If the vehicle receives subsequent BSMs with an associated digest, the vehicle may link the digest to the buffered certificate for signature inspection, which may decrease bandwidth and signaling overhead associated with certificates corresponding to messages within the C-V2X system (e.g., due to sending a digest as opposed to the certificate with each message).

In some cases, the use of a digest may be associated with an interval (e.g., an interval “vMaxCertDigestInterval”). As an illustrative example, the interval may be on the order of 450 milliseconds (ms). In such an example, a BSM transmission may be on the order of 100 ms, which may correspond to a first BSM carrying a full certificate, followed by four messages with a digest of the certificate. After expiration of the interval, a UE sending the BSM may need to include the full certificate again, after which the UE may send BSM messages with a digest for the remaining duration of the interval.

There may be many different types of messages in the wireless communications system100(e.g., a C-V2X system). A message type may refer to a message with a configured payload structure, purpose, periodicity, or other defining characteristic, and messages with different defining characteristics may be referred to as different message types. For example, a UE may utilize a BSM message type, a signal status message (SSM) message type, a vehicle incident report (VIR) message type, or any other number of message types. However, a UE may maintain a separate interval timer (e.g., vMaxCertDigestInterval timer) for each message type, which may be associated with one or more disadvantages. For example, within a single digest interval, a UE may send a full certificate with the first message of each message type. The overhead associated with transmitting separate certificates for multiple message types may increase as a quantity of message types increases. As another example, some event driven messages may be associated with long intervals, or are not periodic. For such messages, a full certificate may be attached during each message (e.g., due to a full interval elapsing before a subsequent message leveraging a digest may be sent). That is, a relatively high quantity of messages of such message types may include the certificate due to the relatively long intervals.

Due to the aforementioned disadvantages, there may be extraneous messages with full certificates sent for each message type, thus further enlarging message and resource size, while also increasing signaling overhead. For example, as discussed previously, a BSM may be transmitted every 100 ms over a 450 ms interval. Additionally, the BSM may be associated with a first certificate and a first digest. A SSM may also be transmitted every 100 ms over a 450 ms interval, where the SSM may be associated with a second certificate and a second digest. A third message (e.g., an event driven VIR), associated with a third certificate and third digest, may not be associated with an interval or may be periodically transmitted. In the aforementioned example, the BSM, the SSM, and the VIR may transmit a full certificate during a first time period, where the first time period may coincide with a first interval associated with the BSM and the SSM. In this example, the full certificates from the BSM, SSM, and VIR may consume bandwidth resources from the network and increase an overall signaling overhead. Additionally, while the BSM and SSM may utilize digests during the first interval, the VIR may transmit a full certificate during each transmission (e.g., due to the event driven nature of the VIR).

However, in some cases, a first wireless device (e.g., the UE115) may transmit a single message of a first message type with a full certificate, where subsequent messages (e.g., of the same type, different types, or both) include digests that correspond to the full certificate. That is, a digest generated from a certificate included in a BSM may be utilized at a UE115or other device to identify the certificate for other message types (e.g., the device may be enabled to identify the certificate of the BSM using the digest of an SSM, as an illustrative example). For example, a full certificate associated with the BSM may be utilized or otherwise correspond to SSM and VIR message types as well as the BSM type, which may alleviate relatively frequently sending full certificates in all message types. By communicating a single message having a first message type to indicate a certificate, and then communicating further messages of any message type including a digest that corresponds to the certificate, overhead in the system from transmitting certificates may be reduced while maintaining secure communications, among other advantages.

FIG.2illustrates an example of a wireless communications system200that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The wireless communications system200may include a UE115-aand a UE115-b,which may be examples of a UE115as described with reference toFIG.1. In some examples, the UE115-aand UE115-bmay operate within a V2X system, a C-V2X system, or both, among other examples of wireless communications systems. While operations and techniques may be discussed below as being performed by particular wireless devices, it is to be understood that the operations and techniques may be performed by any number of wireless devices or type of wireless devices.

The UE115-aand the UE115-bmay exchange messages of different types over a communication link205. The communication link205may be an example of wireless communications links as described herein with reference toFIG.1. For example, the communication link205may be a sidelink communications link (e.g., between devices in a C-V2X system) or another example of a communications link. In some cases, some messages may be periodic messages (e.g., BSM, SSM), while other messages may be event driven (e.g., VIR). The messages exchanged between the UE115-aand the UE115-bmay be associated with a certificate, where the certificate may authenticate senders and receivers within the wireless communication system200. For example, the UE115-a(or another device in a PKI system) may generate a certificate associated with a set of messages to be transmitted to the UE115-b.The UE115-bmay receive a first message from the UE115-a,where the UE115-bmay examine the certificate associated with the set of messages to verify that the sender of the first message is indeed the UE115-a.As an example, the identified certificate may map the UE115-ato a public key and thus the UE115-bmay determine that the UE115-ais authenticated by the PKI as the sender of the set of messages including a certificate or digests of the certificate.

In some examples, such as those described by the present disclosure, the UE115-aand the UE115-bmay support techniques for utilizing certificate and digest mappings to reduce signaling overhead within the wireless communications system200. For example, the UE115-aand the UE115-bmay be configured or otherwise operable to communicate a certificate in a first message type and then use digests of the certificate when sending subsequent messages of any message type. Thus, the UE115-amay refrain from sending certificates for each message type, improving a resource utilization and communications efficiency while the UE115-bmay successfully authenticate or identify the UE115-aas the sender of the messages, which may result in secure communications.

For example, the BSM210may be an example of an anchor message (e.g., based on the UE115-band the UE115-aimplementing an anchor based arrangement), though any message type or message may be an example of an anchor message. The anchor message may be a message that includes the certificate and is the message to which subsequent messages of the same or different message type refer to. Other messages received after the BSM210may include digests linked or associated with the certificate (e.g., the digests may be hashes of the certificate). For example, the UE115-bmay verify that the UE115-ais the sender of the messages using a certificate included in the BSM210, a digest of the certificate included in the SSM215, and the digest of certificate included in the VIR220, or any combination thereof, though other message types and anchor message types are possible.

As an illustrative example, the UE115-amay transmit an SSM215to the UE115-bafter transmitting the BSM210(e.g., within the interval that the certificate of the BSM210is valid or active), and the SSM215may include a digest of the certificate (e.g., instead of the full certificate that was transmitted with the BSM210) The UE115-bmay receive the digest associated with the SSM215and map the digest to the certificate associated with the UE115-a(e.g., the certificate included with the BSM210). Similarly, the UE115-bmay receive a third message (e.g., a VIR220) associated with a digest and verify and authenticate the sender (e.g., the UE115-a) associated with the VIR220using the digest and the certificate of the anchor message (e.g., the BSM210in this example). Thus, the UE115-bmay perform authentication and authorization of the SSM215and the VIR220using associated digests instead of having to receive a full certificate for the SSM215and the VIR220.

Additionally or alternatively to such an anchor based configuration, the UE115-aand UE115-bmay utilize a timer-based configuration. For example, the UEs115may include a single timer associated with multiple message types, which may be an example of an interval timer as described herein (e.g., vMaxCertDigestInterval). In some examples, such a timer and/or duration of the timer may be preconfigured at the devices or may be configured via control signaling (e.g., via a base station105, another UE115, or other wireless devices). The timer may indicate a duration for which a certificate for multiple message types associated with the timer are valid. For example, whatever message that is first transmitted after the start of the timer or restart of the timer may carry a full certificate. Other messages transmitted during the time interval before the timer expires (e.g., after the first transmitted message) may carry digests that link to the first message, regardless of the type of message.

FIG.3illustrates an example of a transmission timeline300that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The transmission timeline300may be utilized by one or more wireless devices, such as a base station105-band a UE115-b,which may be examples of a base station105and a UE115as described with reference toFIG.1. In some examples, the transmission timeline300may include one or more operations, signals, and procedures associated with one or more UEs which may be examples of those discussed with reference toFIG.2. While specific operations and techniques are discussed below, the operations and techniques may be performed in a different order than the example order shown, or the operations performed by the devices may be performed by different devices or at different times.

In some examples, the transmission timeline300may illustrate an example of an anchor based arrangement as described herein, though it is to be understood that the transmission timeline300may include any message type or quantity of message types. In the examples of the transmission timelines described herein, a message on a respective timeline is shown via a line vertical to the time axis. For example, a dotted line may represent a message including a full certificate, a solid line may represent a message including a digest, and the dashed arrows may indicate which digests map to a respective full certificate of another message. In an anchor based arrangement, a particular message type (e.g., the BSM message type) may be configured as the anchor message, and the first message of that type transmitted in an interval may carry the full certificate, whereas subsequent messages transmitted in that interval, regardless of the message type, may only carry a digest of the certificate.

The BSM transmission timeline305may include a first BSM335, which may be part of a set of messages associated with a certificate in the BSM335. The other messages with digests in the first interval320may be included in the set of messages (e.g., the digest included in each of the messages in the first interval320may be a hash or otherwise map to the certificate of the BSM335). In some examples, the BSM335may include the certificate and the associated digest. Additionally or alternatively, other devices in the system may generate the certificate and associated digest. For example, a receiving device may receive the certificate from the transmitting device or another device, the receiving device may generate the digest based on the certificate, the receiving device may receive the digest from the transmitting device or another device, etc.

Thus, a first UE (or another wireless device) may authenticate the identity of a sender of the messages in the various timelines using an anchor message on the BSM transmission timeline305. For example, the first UE may authenticate subsequent BSMs (after receiving the BSM335) received from the second UE during the first interval320using the digest. Additionally or alternatively, the first UE may use the certificate of the BSM335as an anchor for other types of messages received during the first interval320. For example, the first UE may receive one or more SSMs and associated digests, which may correspond to the SSM transmission timeline310during the first interval320. The first UE may identify the certificate of the BSM335based on the digests in the SSMs and authenticate the second UE as the sender UE based on the certificate and digests.

In other words, the first UE may receive SSMs, along with respective digests, after the BSM335and during the first interval320. The first UE may utilize the certificate and digest arrangement associated with the BSM335and the digests associated with the SSMs to authenticate the sender (e.g., the second UE) of the SSMs, for example, without communicating full certificates within the SSMs. Additionally, the first UE may receive a VIR message, which may be associated with the VIR transmission timeline315. In some examples, the VIR transmission timeline315may not be associated with a periodicity or interval. The first UE may utilize the certificate and digest arrangement, and the digest provided with the VIR message, to authenticate the sender of the VIR message, for example, without communicating full certificates in the VIR transmission timeline315.

In some examples, the first interval320may expire (e.g., a timer with a duration that the certificate of the BSM335is valid may expire or restart or both). After the first interval320, the first UE may receive a first message within the second interval325(e.g., the second interval325may be associated with a second certificate when a timer restarts). For example, the first UE may receive a BSM340, along with an associated certificate and digest, during the second interval325. The first UE may perform a similar procedure as those discussed above by utilizing the BSM340as an anchor for subsequent messages received after the BSM340within the second interval325. The first UE may authenticate subsequent BSMs (after receiving the BSM340) received from the second UE during the second interval325using the digest. Additionally or alternatively, the first UE may utilize the certificate and digest arrangement as an anchor for other types of messages received during the second interval325(e.g., SSMs during the second interval325, VIR messages during the second interval325, and so on).

The first UE may continue to utilize BSMs as anchors for subsequent intervals (e.g., BSM345), where a certificate and digest arrangement associated with the BSM345may be used to authenticate other messages with digests during subsequent intervals. That is, the first UE may use digests for other messages received in a given time interval to point to the last BSM (e.g., or in some corner cases, point to the next BSM if no BSM was received before), which may reduce signaling overhead associated with V2X systems. In some other examples, the first UE may use other message types as the anchor message type. For example, if SSMs are the anchor type, the first SSM in an interval may be an anchor message including a full certificate, though other message types are possible. In some examples, the devices in the system may be pre-configured with the anchor message type or control signaling may indicate the anchor message type or both (e.g., devices may change an anchor message type using control signaling).

FIG.4illustrates an example of a transmission timeline400that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The transmission timeline400may be performed by one or more wireless devices, such as a base station105and a UE115, which may be examples of a base station105and a UE115as described with reference toFIG.1. In some examples, the transmission timeline400may include one or more operations, signals, and procedures associated with one or more UEs, which may be examples of those discussed with reference toFIGS.2and3. For example, the transmission timeline400may include aspects as described with reference to the transmission timeline300. While specific operations and techniques are discussed below, the operations and techniques may be performed in a different order than the example order shown, or the operations performed by the devices may be performed by different devices or at different times.

In some examples, the transmission timeline400may illustrate an example of a timer based arrangement as described herein, though it is to be understood that the transmission timeline400may include any message type or quantity of message types. In the examples of the transmission timelines described herein, a message on a respective timeline is shown via a line vertical to the time axis. For example, a dotted line may represent a message including a full certificate, a solid line may represent a message including a digest, and the dashed arrows may indicate which digests map to a respective full certificate of another message.

One or more UEs may utilize a timer-based technique for leveraging a certificate and digest arrangement to authenticate a sender associated with different message types. In some examples, such as that illustrated byFIG.4, a first UE may set or be configured with a timer (e.g., vMaxCertDigestInterval) for messages in the system. The timer may indicate a duration that a certificate for multiple message types is valid. For example, whatever message that is first transmitted (e.g., a first message) after a timer restarts (e.g., after an interval begins) may carry a full certificate, for example, regardless of the type of the first transmitted message. Other messages transmitted during the interval may carry digests that link to the first message.

For example, the first UE may receive an SSM430associated with an SSM transmission timeline410. The SSM430received at the first UE may correspond to a first message received during a time interval420. As such, the SSM430may carry a full certificate authenticating a sender device (e.g., a second UE), where the first UE may utilize the SSM430as a reference to authenticate other messages received from the second UE during the time interval420. For example, the first UE may receive a BSM with a digest from the second UE within the time interval420as shown in the BSM transmission timeline405. In such cases, the first UE may utilize the digest associated with the BSM and the SSM430to authenticate the sender of the BSM while reducing signaling overhead associated with authentication within the system.

The first UE may continue to receive BSM or other messages of other message types, along with associated digests, where the first UE may continue to authenticate the sender of the other messages as the second UE using the SSM430within the time interval420. However, once the time interval has elapsed, the first UE may receive a first message (e.g., a BSM435) within a second time interval425. For example, the first UE may receive a BSM435from the second UE at the beginning of the second time interval425after restarting a timer. As such, the BSM435may carry a full certificate authenticating the second UE, and the first UE may utilize the certificate of the BSM435to authenticate other messages received from the second UE during the second time interval425that have digests linked to the certificate.

For example, the first UE may receive an SSM with a digest from the second UE within the second time interval425. In such cases, the first UE may utilize the digest associated with the SSM to identify the certificate of the BSM435and authenticate the sender of the SSM. Additionally, the second UE may receive a VIR and a digest associated with a VIR transmission timeline415during the second time interval425. The first UE may utilize the digest associated with the VIR to authenticate the sender of the VIR. Such techniques may enable the first UE to reduce the signaling overhead associated with transmitting a certificate for each message type and the processing overhead of maintaining separate timers for each message type, among other benefits.

FIG.5illustrates an example of a transmission timeline500that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The transmission timeline500may be performed by one or more wireless devices, such as a UE, which may be examples of a UE115as described with reference toFIG.1. In some examples, the transmission timeline500may include one or more operations, signals, and procedures associated with the UE or another device, which may be examples of those discussed with reference toFIGS.2-4. While specific operations and techniques are discussed below, the operations and techniques may be performed in a different order than the example order shown, or the operations performed by the devices may be performed by different devices or at different times.

In some examples, the transmission timeline500may illustrate examples of operations for ID changes for the various arrangements as described herein, though it is to be understood that the transmission timeline500may include any message type or quantity of message types. In the examples of the transmission timelines described herein, a message on a respective timeline is shown via a line vertical to the time axis. For example, a dotted line may represent a message including a full certificate, a solid line may represent a message including a digest, and the dashed arrows may indicate which digests map to a respective full certificate of another message. In some examples, the BSM timeline505-aand the SSM timeline510-amay illustrate an example of an ID change for anchor based arrangements and the BSM timeline505-band SSM timeline510-bmay illustrate an example of an ID change for timer based arrangements. Further, though described below as a UE or a vehicle, it is to be understood that any wireless device implementing the techniques described herein may be used.

In some cases, such as in V2X systems, a vehicle (e.g., a UE) may change a source L2 ID (or similar ID that can identify a sender) associated with the vehicle to protect privacy associated with a user, though any identifier may be used. In some examples, a receiver (e.g., a UE115or other wireless device) may utilize the L2 source ID (e.g., or a similar ID that can identify a sender) of different messages to identify what messages are transmitted from the same sender and correlate them together. For example, messages may include a field indicating the L2 source ID and the UE may identify which messages are linked as being from the device with the L2 source ID.

In some cases, a vehicle may change the source L2 ID after an interval (e.g., vCertChangeInterval with a duration of, for example, 300 ms). When the vehicle's source L2 ID is changed, other vehicles may not be able to leverage a certificate and digest mapping to link new messages to old messages received from the vehicle after the L2 ID is changed (e.g., since a new L2 ID may generate or correspond to a different certificate and digest arrangement).

Accordingly, the devices may implement techniques to enable other devices to successfully authenticate messages after an ID change515. For example, after an ID change515-a,messages received between the ID change515-aand a first BSM (e.g., BSM520) may carry a full certificate. By including the full certificate for each message having a non-anchor message type in the interim between the ID change515-a(which invalidates a certificate of a previous anchor message) and a new anchor message, devices may successfully authenticate the messages before a new anchor message is received. In some examples, since BSM (or another message type acting as an anchor message type) may be sent relatively often (e.g., every 100 ms), additional signaling overhead associated with waiting for the first BSM may be relatively low.

As another illustrative example, a BSM transmission timeline505-band an SSM transmission timeline510-bmay be associated with a timer-based arrangement. A first message to be sent after an ID change515-bmay carry a full certificate. Additionally or alternatively, once the first message is sent, a new timer may start (e.g., vMaxCertDigestInterval). That is, the timer indicating the duration for which the old certificate of an interval prior to the ID change515-bmay be restarted and a new interval may be initiated. For example, since the SSM530may be the earliest message received after the ID change515-b(e.g., the SSM530may be the first message received after the timer is restarted), the first UE may utilize the certificate of the SSM530to authenticate subsequent messages from the second UE carrying digests.

In some examples, the timer may expire. In such examples, the first UE may receive a first message within a duration of a subsequent interval of the timer, where the first UE may utilize the certificate of the earliest message within the subsequent interval to authenticate future messages (e.g., with associated digests) sent from the second UE.

Table 1 below shows an example of a BSM for illustrative clarity, though any fields may be included in the message type.

In Table 1, the message includes a field for a digest or a certificate, though other locations or options for indicating the digest or certificate in a message or through other signaling is possible.

FIG.6illustrates an example of a process flow600that supports inter-message certificate and digest arrangement in wireless communications systems in accordance with aspects of the present disclosure. The process flow600may be performed by one or more wireless devices, such as a UE115-cand a UE115-d,which may be examples of a UE115as described with reference toFIG.1. In some examples, the process flow600may include one or more operations, signals, and procedures associated with the UEs115-cand115-d,which may be examples of those discussed with reference toFIGS.2-5. While specific operations and techniques are discussed below, the operations and techniques may be performed in a different order than the example order shown, or the operations performed by the devices may be performed by different devices or at different times. For example, while described as UEs115, it is to be understood that any devices may be used in the process flow600.

At605, the UE115-dmay transmit the first message to the UE115-c.The first message may include a respective certificate (e.g., a PKI certificate). In some examples, the UE115-dmay determine that a data packet (e.g., the first message) is awaiting transmission to the UE115-c.The UE115-dmay generate or otherwise identify the certificate in accordance with the techniques described herein. The first message may include the certificate based on being an anchor message or an earliest message after the initiation of restarting of a timer or interval, or based on being a message subsequent to an ID change.

At610, the UE115-cmay authenticate the sender of the first message as the UE115-d.For example, the UE115-cmay receive the first message having the first message type (e.g., BSM, SSM, VIR, or any other message type) and use the certificate to authenticate the ID of the sender.

In some examples, at615the UE115-cmay determine a certificate and digest arrangement. For example, the UE115-cmay be pre-configured with the arrangement or control signaling may indicate or configure the UE115-cwith the arrangement. In some examples, the arrangement includes a timer based arrangement or an anchor based arrangement as described herein. For example, the UE115-cmay utilize the certificate and digest arrangement to authenticate subsequent messages from the UE115-dbased on a time interval, a timer, an anchor, an updated L2 ID, or some combination thereof. At620, the UE115-dmay transmit a second message to the UE115-c(e.g., a second BSM, VIR, SSM), where the second message carries a digest associated with the UE115-d.In some examples, the second message may have a message type different than the first message. That is, the certificate of the first message having the first message type may correspond to multiple message types including the second message type. Thus, the second message may include a digest that corresponds to or is linked with the certificate of the first message (e.g., the digest may be a hash of the certificate).

At625, the UE115-cmay authenticate the sender of the second message (e.g., the UE115-d). For example, the UE115-cmay identify the certificate buffered in memory after receiving the first message based on the digest of the second message. The UE115-cmay thus identify the sender of the second message as the UE115-d.

FIG.7shows a block diagram700of a device705that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The device705may be an example of aspects of a UE115or other wireless device as described herein. The device705may include a receiver710, a transmitter715, and a communications manager720. The device705may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The communications manager720, the receiver710, the transmitter715, or various combinations thereof or various components thereof may be examples of means for performing various aspects of inter-message certificate and digest arrangements in wireless communications systems as described herein. For example, the communications manager720, the receiver710, the transmitter715, or various combinations or components thereof may support a method for performing one or more of the functions described herein.

In some examples, the communications manager720may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver710, the transmitter715, or both. For example, the communications manager720may receive information from the receiver710, send information to the transmitter715, or be integrated in combination with the receiver710, the transmitter715, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager720may support wireless communication at a first wireless device in accordance with examples as disclosed herein. For example, the communications manager720may be configured as or otherwise support a means for generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate. The communications manager720may be configured as or otherwise support a means for transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate. The communications manager720may be configured as or otherwise support a means for transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message.

Additionally or alternatively, the communications manager720may support wireless communication at a second wireless device in accordance with examples as disclosed herein. For example, the communications manager720may be configured as or otherwise support a means for receiving a first message of a set of messages from a first wireless device, the first message having a first message type and including a certificate for authentication of the set of messages. The communications manager720may be configured as or otherwise support a means for receiving a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type. The communications manager720may be configured as or otherwise support a means for authenticating the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate.

By including or configuring the communications manager720in accordance with examples as described herein, the device705(e.g., a processor controlling or otherwise coupled to the receiver710, the transmitter715, the communications manager720, or a combination thereof) may support techniques for reduced processing power and reduced computational complexity by decreasing payload sizes associated with authenticating senders of messages within a wireless communications system.

FIG.8shows a block diagram800of a device805that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The device805may be an example of aspects of a device705or a UE115as described herein. The device805may include a receiver810, a transmitter815, and a communications manager820. The device805may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

The device805, or various components thereof, may be an example of means for performing various aspects of inter-message certificate and digest arrangements in wireless communications systems as described herein. For example, the communications manager820may include a certificate generation component825, a message transmitter830, a message receiver835, an identity authentication component840, or any combination thereof. The communications manager820may be an example of aspects of a communications manager720as described herein. In some examples, the communications manager820, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver810, the transmitter815, or both. For example, the communications manager820may receive information from the receiver810, send information to the transmitter815, or be integrated in combination with the receiver810, the transmitter815, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager820may support wireless communication at a first wireless device in accordance with examples as disclosed herein. The certificate generation component825may be configured as or otherwise support a means for generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate. The message transmitter830may be configured as or otherwise support a means for transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate. The message transmitter830may be configured as or otherwise support a means for transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message.

Additionally or alternatively, the communications manager820may support wireless communication at a second wireless device in accordance with examples as disclosed herein. The message receiver835may be configured as or otherwise support a means for receiving a first message of a set of messages from a first wireless device, the first message having a first message type and including a certificate for authentication of the set of messages. The message receiver835may be configured as or otherwise support a means for receiving a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type. The identity authentication component840may be configured as or otherwise support a means for authenticating the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate.

FIG.9shows a block diagram900of a communications manager920that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The communications manager920may be an example of aspects of a communications manager720, a communications manager820, or both, as described herein. The communications manager920, or various components thereof, may be an example of means for performing various aspects of inter-message certificate and digest arrangements in wireless communications systems as described herein. For example, the communications manager920may include a certificate generation component925, a message transmitter930, a message receiver935, an identity authentication component940, an anchor message identification component945, a timer initiation component950, an identifier updating component955, a certificate buffering component960, a digest and certificate linking component965, a timer restarting component970, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The communications manager920may support wireless communication at a first wireless device in accordance with examples as disclosed herein. The certificate generation component925may be configured as or otherwise support a means for generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate. The message transmitter930may be configured as or otherwise support a means for transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate. In some examples, the message transmitter930may be configured as or otherwise support a means for transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message.

In some examples, the anchor message identification component945may be configured as or otherwise support a means for identifying the first message as an anchor message of the set of messages based on a configuration of the first wireless device indicating that the anchor message corresponds to the first message type, where transmitting the first message including the certificate is based on the identifying.

In some examples, the certificate generation component925may be configured as or otherwise support a means for generating, subsequent to communicating the set of messages, a second certificate for authentication of a second set of messages and a second digest corresponding to the second certificate. In some examples, the message transmitter930may be configured as or otherwise support a means for transmitting a third message as a second anchor message of the second set of messages based on the third message having the first message type, the third message including the second certificate. In some examples, the message transmitter930may be configured as or otherwise support a means for transmitting a fourth message of the second set of messages, the fourth message including the second digest corresponding to the second certificate.

In some examples, the timer initiation component950may be configured as or otherwise support a means for initiating a timer associated with a duration that the certificate, the digest, or both are valid, where transmitting the first message including the certificate is based on initiating the timer.

In some examples, the first message is an earliest message of the set of messages subsequent to initiating the timer.

In some examples, the certificate generation component925may be configured as or otherwise support a means for generating a second certificate for authentication of a second set of messages and a second digest corresponding to the second certificate based on restarting the timer. In some examples, the message transmitter930may be configured as or otherwise support a means for transmitting a third message of the second set of messages, the third message including the second certificate based on the third message being an earliest message of the second set of messages, where the third message includes the first message type or the second message type. In some examples, the message transmitter930may be configured as or otherwise support a means for transmitting a fourth message including the second digest corresponding to the second certificate.

In some examples, the message transmitter930may be configured as or otherwise support a means for transmitting a third message having a third message type to the second wireless device, the third message including the digest corresponding to the certificate of the first message having the first message type.

In some examples, the message transmitter930may be configured as or otherwise support a means for transmitting an indication of an identifier of the first wireless device to at least the second wireless device, where transmitting the first message, the second message, or both is based on the indication of the identifier.

In some examples, the identifier updating component955may be configured as or otherwise support a means for updating an identifier of the first wireless device based on an expiration of a timer associated with a duration that the identifier is valid. In some examples, the message transmitter930may be configured as or otherwise support a means for transmitting a third message including a second certificate based on updating the identifier.

In some examples, to support wireless communications, the message transmitter930may be configured as or otherwise support a means for transmitting, in a duration between updating the identifier and transmitting the third message, one or more messages having different message types than the first message type associated with the anchor message, each of the one or more messages including the second certificate. In some examples, to support wireless communications, the message transmitter930may be configured as or otherwise support a means for transmitting a fourth message subsequent to the third message, the fourth message including a second digest corresponding to the second certificate.

In some examples, the timer restarting component970may be configured as or otherwise support a means for restarting a timer associated with a duration that the certificate, the digest, or both are valid based on updating the identifier, where transmitting the third message is based on restarting the timer.

In some examples, the third message includes an earliest message of a second set of messages associated with the second certificate, the third message having the first message type or the second message type. In some examples, the certificate has a first data size larger than a second data size of the digest. In some examples, the digest includes a hash of the certificate. In some examples, the certificate is associated with a set of multiple message types including the first message type and the second message type.

Additionally or alternatively, the communications manager920may support wireless communication at a second wireless device in accordance with examples as disclosed herein. The message receiver935may be configured as or otherwise support a means for receiving a first message of a set of messages from a first wireless device, the first message having a first message type and including a certificate for authentication of the set of messages. In some examples, the message receiver935may be configured as or otherwise support a means for receiving a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type. The identity authentication component940may be configured as or otherwise support a means for authenticating the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate.

In some examples, to support authenticating the identity of the first wireless device, the certificate buffering component960may be configured as or otherwise support a means for buffering the certificate in a memory of the second wireless device based on receiving the first message. In some examples, to support authenticating the identity of the first wireless device, the digest and certificate linking component965may be configured as or otherwise support a means for linking the digest of the second message to the certificate of the first message.

In some examples, the message receiver935may be configured as or otherwise support a means for receiving a third message having a third message type from the first wireless device, the third message including the digest corresponding to the certificate of the first message having the first message type. In some examples, the identity authentication component940may be configured as or otherwise support a means for authenticating the first wireless device as the transmitter of the third message based on the digest of the third message and the certificate of the first message.

In some examples, the message receiver935may be configured as or otherwise support a means for receiving a third message including a second certificate for authentication of a second set of message, the third message having any message type of a set of multiple message types. In some examples, the message receiver935may be configured as or otherwise support a means for receiving a fourth message including a second digest corresponding to the second certificate, the fourth message having any message type of the set of multiple message types. In some examples, the identity authentication component940may be configured as or otherwise support a means for authenticating the identity of the first wireless device as the transmitter of the third message and the fourth message based on the second certificate and the second digest.

In some examples, the message receiver935may be configured as or otherwise support a means for receiving an indication of an identifier of the first wireless device, where authenticating the identity of the first wireless device as the transmitter of the set of messages is based on the indication of the identifier. In some examples, the certificate has a first data size larger than a second data size of the digest. In some examples, the digest includes a hash of the certificate. In some examples, the certificate is associated with a set of multiple message types including the first message type and the second message type.

FIG.10shows a diagram of a system1000including a device1005that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The device1005may be an example of or include the components of a device705, a device805, or a UE115as described herein. The device1005may communicate wirelessly with one or more base stations105, UEs115, or any combination thereof. The device1005may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager1020, an input/output (I/O) controller1010, a transceiver1015, an antenna1025, a memory1030, code1035, and a processor1040. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus1045).

The processor1040may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor1040may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor1040. The processor1040may be configured to execute computer-readable instructions stored in a memory (e.g., the memory1030) to cause the device1005to perform various functions (e.g., functions or tasks supporting inter-message certificate and digest arrangements in wireless communications systems). For example, the device1005or a component of the device1005may include a processor1040and memory1030coupled to the processor1040, the processor1040and memory1030configured to perform various functions described herein.

The communications manager1020may support wireless communication at a first wireless device in accordance with examples as disclosed herein. For example, the communications manager1020may be configured as or otherwise support a means for generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate. The communications manager1020may be configured as or otherwise support a means for transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate. The communications manager1020may be configured as or otherwise support a means for transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message.

Additionally or alternatively, the communications manager1020may support wireless communication at a second wireless device in accordance with examples as disclosed herein. For example, the communications manager1020may be configured as or otherwise support a means for receiving a first message of a set of messages from a first wireless device, the first message having a first message type and including a certificate for authentication of the set of messages. The communications manager1020may be configured as or otherwise support a means for receiving a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type. The communications manager1020may be configured as or otherwise support a means for authenticating the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate.

By including or configuring the communications manager1020in accordance with examples as described herein, the device1005may support techniques for reducing signaling overhead in a wireless communications system associated with transmitting certificates while maintaining secure communications

In some examples, the communications manager1020may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver1015, the one or more antennas1025, or any combination thereof. Although the communications manager1020is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager1020may be supported by or performed by the processor1040, the memory1030, the code1035, or any combination thereof. For example, the code1035may include instructions executable by the processor1040to cause the device1005to perform various aspects of inter-message certificate and digest arrangements in wireless communications systems as described herein, or the processor1040and the memory1030may be otherwise configured to perform or support such operations.

FIG.11shows a flowchart illustrating a method1100that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The operations of the method1100may be implemented by a UE or its components as described herein. For example, the operations of the method1100may be performed by a UE115as described with reference toFIGS.1through10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At1105, the method may include generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate. The operations of1105may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1105may be performed by a certificate generation component925as described with reference toFIG.9.

At1110, the method may include transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate. The operations of1110may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1110may be performed by a message transmitter930as described with reference toFIG.9.

At1115, the method may include transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message. The operations of1115may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1115may be performed by a message transmitter930as described with reference toFIG.9.

FIG.12shows a flowchart illustrating a method1200that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The operations of the method1200may be implemented by a UE or its components as described herein. For example, the operations of the method1200may be performed by a UE115as described with reference toFIGS.1through10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At1205, the method may include generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate. The operations of1205may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1205may be performed by a certificate generation component925as described with reference toFIG.9.

At1210, the method may include identifying the first message as an anchor message of the set of messages based on a configuration of the first wireless device indicating that the anchor message corresponds to the first message type, where transmitting the first message including the certificate is based on the identifying. The operations of1210may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1210may be performed by an anchor message identification component945as described with reference toFIG.9.

At1215, the method may include transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate. The operations of1215may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1215may be performed by a message transmitter930as described with reference toFIG.9.

At1220, the method may include transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message. The operations of1220may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1220may be performed by a message transmitter930as described with reference toFIG.9.

FIG.13shows a flowchart illustrating a method1300that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The operations of the method1300may be implemented by a UE or its components as described herein. For example, the operations of the method1300may be performed by a UE115as described with reference toFIGS.1through10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At1305, the method may include generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate. The operations of1305may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1305may be performed by a certificate generation component925as described with reference toFIG.9.

At1310, the method may include initiating a timer associated with a duration that the certificate, the digest, or both are valid, where transmitting the first message including the certificate is based on initiating the timer. The operations of1310may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1310may be performed by a timer initiation component950as described with reference toFIG.9.

At1315, the method may include transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and including the certificate. The operations of1315may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1315may be performed by a message transmitter930as described with reference toFIG.9.

At1320, the method may include transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, where the second message includes the digest corresponding to the certificate of the first message. The operations of1320may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1320may be performed by a message transmitter930as described with reference toFIG.9.

FIG.14shows a flowchart illustrating a method1400that supports inter-message certificate and digest arrangements in wireless communications systems in accordance with aspects of the present disclosure. The operations of the method1400may be implemented by a UE or its components as described herein. For example, the operations of the method1400may be performed by a UE115as described with reference toFIGS.1through10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At1405, the method may include receiving a first message of a set of messages from a first wireless device, the first message having a first message type and including a certificate for authentication of the set of messages. The operations of1405may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1405may be performed by a message receiver935as described with reference toFIG.9.

At1410, the method may include receiving a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, where the second message includes a digest corresponding to the certificate of the first message having the first message type. The operations of1410may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1410may be performed by a message receiver935as described with reference toFIG.9.

At1415, the method may include authenticating the identity of the first wireless device as the transmitter of the set of messages based on the digest and the certificate. The operations of1415may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1415may be performed by an identity authentication component940as described with reference toFIG.9.

Aspect 1: A method for wireless communication at a first wireless device, comprising: generating, by the first wireless device, a certificate for authentication of a set of messages and a digest corresponding to the certificate; transmitting a first message of the set of messages to a second wireless device, the first message having a first message type and comprising the certificate; and transmitting a second message of the set of messages to the second wireless device, the second message having a second message type different than the first message type, wherein the second message comprises the digest corresponding to the certificate of the first message.

Aspect 2: The method of aspect 1, further comprising: identifying the first message as an anchor message of the set of messages based at least in part on a configuration of the first wireless device indicating that the anchor message corresponds to the first message type, wherein transmitting the first message comprising the certification is based at least in part on the identifying.

Aspect 3: The method of aspect 2, further comprising: generating, subsequent to communicating the set of messages, a second certificate for authentication of a second set of messages and a second digest corresponding to the second certificate; transmitting a third message as a second anchor message of the second set of messages based at least in part on the third message having the first message type, the third message comprising the second certificate; and transmitting a fourth message of the second set of messages, the fourth message comprising the second digest corresponding to the second certificate.

Aspect 4: The method of any of aspects 1 through 3, further comprising: initiating a timer associated with a duration that the certification, the digest, or both are valid, wherein transmitting the first message comprising the certificate is based at least in part on initiating the timer.

Aspect 5: The method of aspect 4, wherein the first message is an earliest message of the set of messages subsequent to initiating the timer.

Aspect 6: The method of any of aspects 4 through 5, further comprising: generating a second certificate for authentication of a second set of messages and a second digest corresponding to the second certificate based at least in part on restarting the timer; transmitting a third message of the second set of messages, the third message comprising the second certificate based at least in part on the third message being an earliest message of the second set of messages, wherein the third message comprises the first message type or the second message type; and transmitting a fourth message comprising the second digest corresponding to the second certificate.

Aspect 7: The method of any of aspects 1 through 6, further comprising: transmitting a third message having a third message type to the second wireless device, the third message comprising the digest corresponding to the certificate of the first message having the first message type.

Aspect 8: The method of any of aspects 1 through 7, further comprising: transmitting an indication of an identifier of the first wireless device to at least the second wireless device, wherein transmitting the first message, the second message, or both is based at least in part on the indication of the identifier.

Aspect 9: The method of any of aspects 1 through 8, further comprising: updating an identifier of the first wireless device based at least in part on an expiration of a timer associated with a duration that the identifier is valid; and transmitting a third message comprising a second certificate based at least in part on updating the identifier.

Aspect 10: The method of aspect 9, wherein the third message comprises an anchor message, further comprising: transmitting, in a duration between updating the identifier and transmitting the third message, one or more messages having different message types than the first message type associated with the anchor message, each of the one or more messages comprising the second certificate; and transmitting a fourth message subsequent to the third message, the fourth message comprising a second digest corresponding to the second certificate.

Aspect 11: The method of any of aspects 9 through 10, further comprising: restarting a timer associated with a duration that the certification, the digest, or both are valid based at least in part on updating the identifier, wherein transmitting the third message is based at least in part on restarting the timer.

Aspect 12: The method of aspect 11, wherein the third message comprises an earliest message of a second set of messages associated with the second certificate, the third message having the first message type or the second message type.

Aspect 13: The method of any of aspects 1 through 12, wherein the certificate has a first data size larger than a second data size of the digest.

Aspect 14: The method of aspect 13, wherein the digest comprises a hash of the certificate.

Aspect 15: The method of any of aspects 1 through 14, wherein the certificate is associated with a plurality of message types comprising the first message type and the second message type.

Aspect 16: A method for wireless communication at a second wireless device, comprising: receiving a first message of a set of messages from a first wireless device, the first message having a first message type and comprising a certification for authentication of the set of messages; receiving a second message of the set of messages from the first wireless device, the second message having a second message type different than the first message type, wherein the second message comprises a digest corresponding to the certificate of the first message having the first message type; and authenticating the identity of the first wireless device as the transmitter of the set of messages based at least in part on the digest and the certificate.

Aspect 17: The method of aspect 16, wherein authenticating the identity of the first wireless device comprises: buffering the certificate in a memory of the second wireless device based at least in part on receiving the first message; and linking the digest of the second message to the certificate of the first message.

Aspect 18: The method of any of aspects 16 through 17, further comprising: receiving a third message having a third message type from the first wireless device, the third message comprising the digest corresponding to the certificate of the first message having the first message type; and authenticating the first wireless device as the transmitter of the third message based at least in part on the digest of the third message and the certificate of the first message.

Aspect 19: The method of any of aspects 16 through 18, further comprising: receiving a third message comprising a second certificate for authentication of a second set of message, the third message having any message type of a plurality of message types; receiving a fourth message comprising a second digest corresponding to the second certificate, the fourth message having any message type of the plurality of message types; and authenticating the identity of the first wireless device as the transmitter of the third message and the fourth message based at least in part on the second certificate and the second digest.

Aspect 20: The method of any of aspects 16 through 19, further comprising: receiving an indication of an identifier of the first wireless device, wherein authenticating the identity of the first wireless device as the transmitter of the set of messages is based at least in part on the indication of the identifier.

Aspect 21: The method of any of aspects 16 through 20, wherein the certificate has a first data size larger than a second data size of the digest.

Aspect 22: The method of aspect 21, wherein the digest comprises a hash of the certificate.

Aspect 23: The method of any of aspects 16 through 22, wherein the certificate is associated with a plurality of message types comprising the first message type and the second message type.

Aspect 25: An apparatus for wireless communication at a first wireless device, comprising at least one means for performing a method of any of aspects 1 through 15.

Aspect 28: An apparatus for wireless communication at a second wireless device, comprising at least one means for performing a method of any of aspects 16 through 23.

Aspect 29: A non-transitory computer-readable medium storing code for wireless communication at a second wireless device, the code comprising instructions executable by a processor to perform a method of any of aspects 16 through 23.