Our application requires AES-256 encryption, but the K60 with its hardware cryptography accelerator is overkill. Libraries are provided by Freescale for CAU use (in example form at least). As far as I can tell, software based (non-acceletated) crytpgraphic libraries are not available for the kinetis. Can anyone refute this observation or make a recommendation on a 3rd party solution? Generating our own routines is certainly an option.
Have you looked at AN4307? Specifically AN4307SW