In 6G, a range of new technologies will emerge based on intelligent network structures. The connection between 6G technology and AI-based intelligent networks will make communication more convenient for humans, but may also rise to new security threats. As a result, network security and trustworthiness will become a key challenges in 6G. This chapter categorizes security threats in 6G into four areas; openness, post quantum cryptography, privacy preserving, and auction threats. We will also introduce security solutions that can mitigate these security threats in 6G.