Add message-level encryption
Add the ability to specify message-level encryption on all client/server requests. Allow custom selection of encryption techniques (RSA, AES, etc.) for each direction, and the initialization vectors. Server-side I can see doing this via plug-ins and / or attributes.
Create a subset of client libraries that handle encryption, perhaps using function pointers to encrypt / decrypt.
Its been suggested previously by Demois on different forums.
Encrypted Messaging was added in v4.0.42: https://github.com/ServiceStack/ServiceStack/wiki/Encrypted-Messaging
Johann Klemmack commented
Yeah, ran into this attempting to deploy Internet-connected kiosks at various retail locations. They retailer only allows us to communicate on a non-standard port (9000 something), and forbids DNS lookups. That means secure communication has to be via self-signed certs, pointing at specific IP addresses. Much more elegant would to just POST everything and encrypt the body.
Dylan v.d Merwe commented
Wow cool idea!