Named Data Networking (NDN) is considered to be a viable replacement of the traditional IP networking for the next generation Internet architecture. NDN is a data centric, rather than host centric, approach to discovery and retrieval of information distributed across a network. This paradigm shift results in a host of new challenges, one of which is authentication of data and data-sources. NDN requires each content producer to digitally sign each data packet it produces. While the use of digital signatures certainly accomplishes data and data source authentication, it imposes significant overhead on the whole network. In this paper, we propose a novel data and source authentication mechanism that relies primarily on hashing. The mechanism utilizes hash chaining to ensure that unauthorized modification, insertion, or deletion of data can be easily detected by routers and content consumers.