This book constitutes the refereed proceedings of the 6th International Conference on Security and Privacy in New Computing Environments, SPNCE 2023, held in Guangzhou, China, during November 25-26, 2023. The 29 full papers were selected from 75 submissions and are grouped in these thematical parts: IoT, network security and privacy challenges; multi-party privacy preserving neural networks; security and privacy steganography and forensics.