3GPP 24.501 v20.0.0 — the document's own text
9.11.3.12 Additional 5G security information
Taught in 4. Inside TS 24.501, the document at the centre (CT1 — the group that writes what your phone says, overview).
The purpose of the Additional 5G security information information element is to provide the UE with additional security parameters (e.g. horizontal derivation parameter) or to request the UE to retransmit an initial NAS message during a security mode control procedure as defined in 3GPP TS 33.501 [24]. The UE uses these parameters for completion of security mode control procedure.
The Additional 5G security information information element is coded as shown in figure 9.11.3.12.1 and table 9.11.3.12.1.
The Additional 5G security information is a type 4 information element with a length of 3 octets.
| 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
|---|---|---|---|---|---|---|---|---|
| Additional 5G security information IEI | octet 1 | |||||||
| Length of Additional 5G security information contents | octet 2 | |||||||
| 0Spare | 0Spare | 0Spare | 0Spare | 0Spare | 0Spare | RINMR | HDP | octet 3 |
Figure 9.11.3.12.1: Additional 5G security information information element
Table 9.11.3.12.1: Additional 5G security information information element
| Horizontal derivation parameter (HDP) (octet 3, bit 1) | ||
|---|---|---|
| 0 | KAMF derivation is not required | |
| 1 | KAMF derivation is required | |
| Retransmission of initial NAS message request (octet 3, bit 2) | ||
| 0 | Retransmission of the initial NAS message not requested | |
| 1 | Retransmission of the initial NAS message requested | |
| Bits 3 to 8 of octet 3 are spare and shall be coded as zero. |