The protocol used to secure internet communications and ensure data integrity is Transport Layer Security (TLS). TLS is designed to provide a secure channel between client-server communications over a computer network, encrypting the data transmitted to protect it from eavesdropping and tampering. It verifies the identities of both parties through digital certificates, ensuring that data integrity and confidentiality are maintained during transmission. Widely used in web browsing, email, and messaging services, TLS is essential for maintaining trusted communications in a digital environment, further promoting consumer confidence in online transactions.