The Internet of things (IoT) is intended for ubiquitous connectivity among different entities or “things”. While it provides effective and efficient solutions to many real world challenges, the security aspect of it has always been questioned. The situation is further exacerbated by the number of connected devices growing exponentially. As a result, security and privacy has emerged as a significant challenge for the IoT. In this paper, we aim to provide a thorough survey on IoT security and privacy challenges from the perspective of technologies and architecture used. This work focuses on IoT intrinsic vulnerabilities and their implications to the fundamental information security challenges in confidentiality, integrity, and availability. The approach of this survey is to summarize and synthesize published work in IoT; relate it to the security conjuncture of the field; and project future research directions.