Disclosed is a system, method, and program for distributing computer software from a first computer system. The first computer system receives a request for software from a second computer system. In response, the first computer system generates a message, encrypts the generated message, and transmits the encrypted message to the second computer system. The first computer system later receives an encrypted response from the second computer system and processes the encrypted response to determine whether the second computer system is authorized to access the software. The second computer system is permitted access to the software after determining that the second computer system is authorized to access the software. To access the computer software with the second computer system, the second computer system transmits a request for the software to the first computer system. The second computer system receives an encrypted message from the first computer system and processes the encrypted message to generate a response message. The response message is transmitted to the first computer system. In response, the second computer system is permitted access to the requested software.