Grundner-Culemann, S. (2017):
Identity-based source authentication in constrained networks
Resource constrained devices communicating among themselves and exchanging data (e.g. in automated homes) are becoming ever more prevalent. Unfortunately, so are reports of them having security flaws. This is at least in part due to the difficulty that arise from the strict limitations on power, memory, and energy use the items are subject to. Classical methods often rely on computationally challenging methods or large keys for security, especially in Public Key Cryptography. However, to identify individual devices in a network symmetric keys as used to ensure confidentiality within the group are not sufficient. Adi Shamir's proposal to use the identity itself as public key (identity-based cryptography) is therefore a useful idea in constrained environments. The implications of using it in group communication are hardly addressed in the literature, however. Especially the issue of key revocation deserves close attention. In order to evaluate the suitability of identity-based signatures in a constrained group setting, the thesis proposes a taxonomy that allows the comparison of different schemes with varying characteristics. To facilitate its use, a comprehensible introduction to the most important concepts related to identity-based signatures is provided, along with some guidance on details of an IBS scheme beyond the taxonomy's reach.