Enabling a software application to be executed on a mobile station

1. A method for enabling a software application to be executed on a mobile station, wherein the software application comprises a first secured software part, a second secured software part and an inverse module, wherein the mobile station comprises a mobile equipment and a subscriber identity module, the method comprising, during execution of the software application on the mobile equipment:

the software application inputting challenge data originating from the software application to the subscriber identity module, wherein the challenge data comprises at least a part of runtime data of the software application at the end of the first secured software part when being executed in the mobile equipment;

generating first response data in the subscriber identity module, wherein said generating comprises the subscriber identity module performing a first security function using (a) data which is associated with the subscriber identity module and (b) the challenge data;

enabling continued execution of the software application in dependence of the first response data;

transmitting the challenge data from the mobile station to a verification server;

generating second response data in the verification server in dependence of the challenge data;

enabling the continued execution of the software application in further dependence of the second response data;

inputting the challenge data to a cryptographic function of the verification server;

obtaining intermediate data from the cryptographic function using the challenge data and a first key as input to the cryptographic function;

transmitting the second response data from the verification server to the mobile station, wherein the second response data is based on the intermediate data;

inputting the second response data or a derivation of the second response data to an inverse cryptographic function in the inverse module to thereby obtain an inverted response data using a second key, wherein the inverted response data comprises the challenge data if the inverse function and the second key in the inverse module matches the cryptographic function and the first key in the verification server; and

providing the inverted response data to the second secured software part to enable the continued execution of the software application.

2. The method according to claim 1 , further comprising:

transmitting identity data from the mobile station to the verification server;

transmitting the identity data and the challenge data from the verification server to an authentication center;

generating third response data in the authentication center, wherein the authentication center is configured to perform a second security function corresponding to the identity data and wherein the third response data is generated using the second security function with the challenge data as input to the second security function;

receiving the third response data from the authentication center in the verification server; and

obtaining the second response data from a first combine module in the verification server with the intermediate data and the third response data as input to the first combine module.

3. The method according to claim 2 , further comprising:

transmitting the first response data from the mobile station to the verification server, and wherein the obtaining of the second response data comprises:

comparing the first response data with the third response data in the first combine module to obtain a comparison result; and

modifying the second response data depending on the comparison result.

4. The method according to claim 2 , wherein the software application further comprises a second combine module, and the method further comprises:

obtaining the derivation of the second response data using the second combine module with the first response data and the second response data as input to the second combine module.

5. The method according to claim 4 , further comprising:

generating random data in the verification server;

transmitting the random data instead of the challenge data from the verification server to the authentication center for the generation of the third response data;

transmitting the random data from the verification server to the mobile station; and

inputting the random data instead of the challenge data to the subscriber identity module for the generation of the first response data.

6. The method according to claim 4 , further comprising transmitting the first response data from the mobile station to the verification server, and wherein the second combine module is a part of the verification server.

7. The method according to claim 2 , wherein the second security function comprises a second combined cipher key generation and authentication algorithm and wherein the third response data comprises at least one of a second cipher key and a second signed response.

8. The method according to claim 7 , further comprising combining the second cipher key and the second signed response using a second combining function to obtain the third response data.

9. The method according to claim 1 , wherein the order of the verification server and the inverse module is reversed, wherein the verification server is configured to perform the inverse function, and wherein the inverse module is configured to perform the cryptographic function.