Which algorithm is used in GSM for encryption?

Encrypted voice and data communications between the MS and the network is accomplished by using the ciphering algorithm A5. Encrypted communication is initiated by a ciphering mode request command from the GSM network.

How GPRS network authentication is achieved?

The GPRS operator wants to know who is trying to initiate a connection with the network. The aim of the authentication process is to identify that the user has a correct SIM card with a valid Ki key. This process must be verified without sending Ki over the radio interface.

What is A3 algorithm in GSM?

The A3 ciphering algorithm is used to authenticate each mobile by verifying the user password within the SIM with the cryptographic key at the MSC. The A5 ciphering algorithm is used for encryption. It provides scrambling for 114 coded bits sent in each TS. The A8 is used for ciphering key.

How does A3 algorithm work?

What is A3 A5 A8 algorithm in GSM?

Three security algorithms are documented in GSM specifications for this purpose. They are called A3, A5 and A8. A3 is authentication algorithm, A8 is ciphering key generating algorithm and A5 is a stream cipher for encryption of user data transmitted between mobile and base station.

How to test the behaviour of the MS with ciphering?

To test the behaviour of the MS if the network accepts the authentication and ciphering procedure with ciphering. 44.2.5.2.1.3 Method of test System Simulator: Two cells (not simultaneously activated), cell A in MCC1/MNC1/LAC1/RAC1, cell B in MCC1/MNC1/LAC1/RAC2. Both cells are operating in network operation mode II. Mobile Station:

How does the SS initiate the authentication and ciphering procedure?

A GPRS attach is performed, and the SS initiates an authentication and ciphering procedure. The SS checks the value SRES sent by the MS in the AUTHENTICATION AND CIPHERING RESPONSE message.

Which encryption algorithm is used for the execution counter test?

GEA1, GEA2, GEA3 or GEA4 encryption is used depending on the execution counter K. The test is performed for all GEAx encryption algorithm supported by the MS. Maximum duration of test

How does the MS test the Geax encryption algorithm?

The MS initiates a routing area updating procedure, and the SS initiates an authentication and ciphering procedure to start ciphering. GEA1, GEA2, GEA3 or GEA4 encryption is used depending on the execution counter K. The test is performed for all GEAx encryption algorithm supported by the MS.