Abstract: It is widely recognized that data security will play a central role in future IT systems. Providing public-key cryptographic primitives, which are the core tools for security, is often difficult on embedded processor due to computational, memory and power constraints. This contribution appears to be the first thorough comparison of two public-key families, namely elliptic curve (ECC) and hyperelliptic curve cryptosystems (HECC) on a wide range of embedded processor types (ARM, ColdFire, PowerPC). We investigated the influence of the processor type, resources, and architecture regarding throughput. Furthermore, we improved previously known HECC algorithms resulting in a more efficient arithmetic. BibTeX: @ARTICLE{A-WPWPSK03, AUTHOR = "T. Wollinger and J. Pelzl and V. Wittelsberger and C Paar and G. Saldamli and \c{C}. K. Ko\c{c}", JOURNAL = "ACM Transactions in Embedded Computing Systems (TECS)", TITLE = "Elliptic \& Hyperelliptic Curves on Embedded $\mu$P", YEAR = "2004", NUMBER = "3", PAGES = "509--533", MONTH = "August", VOLUME = "3", NOTE = "Special Issue on Embedded Systems and Security" }