Internet of things (IOT) introduces capability to connect and identify different physical objects into unified system. IOT allows these objects to match computation and made network decisions. In such a disparate world computation, each one of IOT consumer will have a specific role to serve in the form of communication. There is a hazard that an unknown attacker can trash the protection of the network. A number of serious challenges are part of IOT about access to personal information related to the system and privacy of individuals. At this point protection and privacy becomes a major concern in the IOT. Security needs to establish; we need to be careful to maintain confidentiality, authentication, and non-repudiation as well as data integrity. From this article, we deal with different security issues in IOT, addressing different conventional IOT device security techniques and their flaws. Later we recognize a few appropriate algorithms for security; this survey summarizes the security threats.