A framework for secure download for software-defined radio

This article proposes a framework for establishing secure download for software-defined radio (SDR) that follows the current recommendations of SDR-related organizations, and can be employed in a variety of SDR architectures. The main goals of the security system are verification of the declared identity of the source that produces the software to be downloaded, control and verification of integrity of the downloaded data, disabling of the ability to run unauthorized software on the software-defined terminal, and secrecy of the transmitted data to prevent problems such as loss of intellectual property contained in the software. The system includes the following parties: manufacturers of the terminal hardware and software; government authorities relevant for SDR and users of SDR terminals. The underlying ideas for system development include employment of four different cryptographic techniques and tamper-resistant hardware. The cryptographic techniques employed are a secret key encryption technique, a public key encryption technique, a technique for cryptographic hashing, and a technique for digital signature. An important feature of the system is that it provides the possibility to exchange cryptographic components in an automatic manner. The proposed system is flexible, highly secure to protect both users and manufacturers, and provides a framework for the secure commercial implementation of SDR.