Do I still need OAuth or API Key with HTTPS for Restful webservice

Question

I am creating an application and native apps which shall access a bunch of RestFul Webservices. We are already using HTTPS to secure the API, but wanted to understand if we still need something like an API Key or OAuth Key to authenticate the data

Answer 1

Encryption and Authentication are two separate things. Encryption merely prevents outside parties from snooping the transmitted data. You need Authentication if you want to control who has access to which resources using the API.