8 Integrity protection

3GPP43.051GSM/EDGE Overall descriptionRelease 17Stage 2TS

Tools: ARFCN - Frequency Conversion for 5G NR/LTE/UMTS/GSM

8.1 Integrity protection on RRC messages

Integrity protection with a 32-bit MAC-I shall be performed on all RRC messages, with the exceptions defined in 3GPP TS 44.118.

There may be one IK for CS connections (IK_CS), established between the CS service domain and the user and one IK for PS connections (IK_PS) established between the PS service domain and the user.

The data integrity of radio bearers for user data is not protected.

The signalling radio bearers are used for transfer of signalling data for services delivered by both CS and PS service domains. These signalling radio bearers are data integrity protected by the IK of the service domain for which the most recent security mode negotiation took place. This may require that the integrity key of an (already integrity protected) ongoing signalling connection has to be changed, when a new connection is established with another service domain, or when a security mode negotiation follow a re-authentication during an ongoing connection.

8.2 Integrity protection on RLC/MAC control messages

RLC/MAC control messages are not integrity protected.

8.3 Calculation of message authentication code

The MS shall calculate the message authentication code in accordance with 3GPP TS 33.102. The construction of the input parameter MESSAGE (3GPP TS 33.102) for the integrity algorithm is FFS.