On the specification of symmetric key management parameters for secure space missions

Although the vast majority of space communications are in-the-clear, security is an emerging trend in spacecraft missions. However, key management in space has received limited attention. This work provides an approach to symmetric key management with justification of parameters. Unlike previous approaches, quantitative analysis and models are proposed. Specifically, key hierarchy, key roles, key lengths and corresponding crypto periods are specified, based upon models of known attacks, and computing power. These results are crucial in order to support future secure space missions and cryptographic modules onboard spacecrafts.