When looking at the downloads available on the Cisco site, they have a regular version of the file and a NO PAYLOAD ENCRYPTION version. What is the difference? And why would one choose one over the other?
From the Cisco website:
Universal images with the universalk9_npe" designation in the image name: The strong enforcement of encryption capabilities provided by Cisco Software Activation satisfies requirements for the export of encryption capabilities. However, some countries have import requirements that require that the platform does not support any strong crypto functionality such as payload cryptography. To satisfy the import requirements of those countries, the `npe' universal image does not support any strong payload encryption. This image supports security features like Zone-Based Firewall, Intrusion Prevention through SECNPE-K9 license.
So you would use this image if you were in a country that has import restrictions on strong crypto.