Which encryption mode replaced AES CCMP for Wi-Fi encryption and is used in the cipher "ECDHE-RSA-AES128-GCM-SHA256"?

The Galois Counter Mode (AES-GCM) is a mode of operation for symmetric key cryptography that combines the AES encryption algorithm with the Galois mode of authentication. This mode is recognized for its performance and security characteristics, making it suitable for high-speed network encryption.

AES-GCM provides both confidentiality through encryption and integrity through authentication, which is essential for secure communication protocols such as those used in Wi-Fi. It improves upon the previous encryption mode, CCMP, by offering not just encryption for data transmission but also ensuring the integrity and authenticity of the data, thus making it a robust choice for modern security requirements.

In the context of the cipher "ECDHE-RSA-AES128-GCM-SHA256," the AES-GCM component specifically indicates that GCM is utilized for the encryption process alongside AES with a 128-bit key. This mode's design integrates counter mode encryption with Galois field multiplication to provide both encryption and authentication seamlessly, making it more efficient for secure connections than earlier methods like CCMP.