A system, method and computer program for authorizing a mobile station to use a product, service, access or other rights provided by a service provider through the use of digital signatures. These digital signatures are based on a shared signing key, and can be verified using a signature verification service. This system, method and computer program will validate the identity of the mobile station being used utilizing long term keys stored in the mobile station and an authentication center. The system, method and computer program will then utilize the signing key and the signature verification service to verify digital signatures that enable the authorization to access products, services, access or other rights using a mobile station. When this system, method and computer program is used for authorizing payment transactions, the gateway will verify the authenticity of any charges made based on the signatures received. Thus, a user of this system, method and computer program can purchase goods and services without fear of fraud or errors.