B.1 Protection of RRC messages

38.3313GPPNRProtocol specificationRadio Resource Control (RRC)Release 15TS

The following list provides information which messages can be sent (unprotected) prior to AS security activation and which messages can be sent unprotected after AS security activation. Those messages indicated "-" in "P" column should never be sent unprotected by gNB or UE. Further requirements are defined in the procedural text.

P…Messages that can be sent (unprotected) prior to AS security activation

A – I…Messages that can be sent without integrity protection after AS security activation

A – C…Messages that can be sent unciphered after AS security activation

NA… Message can never be sent after AS security activation

Message

P

A-I

A-C

Comment

CounterCheck

CounterCheckResponse

DLInformationTransfer

+

FailureInformation

LocationMeasurementIndication

MIB

+

+

+

MeasurementReport

Measurement configuration may be sent prior to AS security activation. But: In order to protect privacy of UEs, MeasurementReport is only sent from the UE after successful AS security activation.

MobilityFromNRCommand

Paging

+

+

+

RRCReconfiguration

+

The message shall not be sent unprotected before AS security activation if it is used to perform handover or to establish SRB2 and DRBs.

RRCReconfigurationComplete

+

Unprotected, if sent as response to RRCReconfiguration which was sent before AS security activation.

RRCReestablishment

+

Integrity protection applied, but no ciphering.

RRCReestablishmentComplete

RRCReestablishmentRequest

+

This message is not protected by PDCP operation. However, a shortMAC-I is included.

RRCReject

+

+

+

Justification for A-I and A-C: the message can be sent in SRB0 in RRC_INACTIVE state, after the AS security is activated.

RRCRelease

+

Justification for P: If the RRC connection only for signalling not requiring DRBs or ciphered messages, or the signalling connection has to be released prematurely, this message is sent as unprotected. RRCRelease message sent before AS security activation cannot include deprioritisationReq, suspendConfig, redirectedCarrierInfo, cellReselectionPriorities information fields.

RRCResume

RRCResumeComplete

RRCResumeRequest

+

This message is not protected by PDCP operation. However, a resumeMAC-I is included.

RRCResumeRequest1

+

This message is not protected by PDCP operation. However, a resumeMAC-I is included.

RRCSetup

+

+

+

Justification for A-I and A-C: the message can be sent in SRB0 in RRC_INACTIVE or RRC_CONNECTED states, after the AS security is activated.

RRCSetupComplete

+

NA

NA

RRCSetupRequest

+

NA

NA

RRCSystemInfoRequest

+

+

+

Justification for A-I and A-C: the message can be sent in SRB0 in RRC_INACTIVE state, after the AS security is activated.

SIB1

+

+

+

SCGFailureInformation

SCGFailureInformationEUTRA

SecurityModeCommand

+

NA

NA

Integrity protection applied, but no ciphering (integrity verification done after the message received by RRC).

SecurityModeComplete

+

The message is sent after AS security activation. Integrity protection applied, but no ciphering. Ciphering is applied after completing the procedure.

SecurityModeFailure

+

NA

NA

Neither integrity protection nor ciphering applied.

SystemInformation

+

+

+

UEAssistanceInformation

UECapabilityEnquiry

+

The network should retrieve UE capabilities only after AS security activation.

UECapabilityInformation

+

ULInformationTransfer

+

ULInformationTransferMRDC