I'm using magento.restAPI and i'm very new to magento and i havent used any previous version of magento. Currently i'm having a magento rest Api i want to know whether its the same authentication process being used in magento 1.8 and 1.6
If you look at the Magento changelog
You'll notice the
Major Highlights, the 8th bullet isted is:
Added REST API
If you browse through all of the available changelogs, there is no further mention of REST modification in versions later than 22.214.171.124.
So yes, there is a difference in the REST API between versions 1.6 & 1.8 which is the existence of the API itself ;-)