C.0 Scope

3GPP43.020Release 17Security related network functionsTS

This annex specifies the cryptological algorithms which are needed to provide the various security features and mechanisms defined in, respectively, 3GPP TS 42.009 and 3GPP TS 43.020.

The following three algorithms are considered in 3GPP TS 43.020:

– Algorithm A3: Authentication algorithm;

– Algorithm A5: Ciphering/deciphering algorithm;

– Algorithm A8: Ciphering key generator.

Algorithm A5 must be common to all GSM PLMNs and all mobile stations (in particular, to allow roaming). The external specifications of Algorithm A5 are defined in subclause C.1.3. The internal specifications of Algorithm A5 are managed under the responsibility of GSM/MoU; they will be made available in response to an appropriate request.

Algorithms A3 and A8 are at each PLMN operator discretion. Only the formats of their inputs and outputs must be specified. It is also desirable that the processing times of these algorithms remain below a maximum value. Proposals for Algorithm A3 and A8 are managed by GSM/MoU and available, for those PLMN operators who wish to use them, in response to an appropriate request.