5G Air Interface Ciphering is a security mechanism used to protect the confidentiality of data transmitted between a user device and the 5G base station over the radio link. It ensures that the data exchanged is encrypted, preventing unauthorized access and eavesdropping. The ciphering process involves using algorithms like AES (Advanced Encryption Standard) or ZUC, which are applied to the data before transmission. This process is crucial for maintaining the privacy and integrity of user communications in the 5G network, supporting secure services in both consumer and enterprise use cases.