We are progressing on our upgrade from DF3.2 to WebApp

The DF32 CM program creates a URL calling a DFlex WebApp
One component is an AccessKey that I want to do a simple encrypt in the DF3.2 app that I can decrypt at the WebApp end. Maybe using Base64DecodeFromStr

Any thoughts on how I can do a Base64EncodeFromStr in DF3.2 CM?
Or a real simple encrypt / decrypt at both ends?