TLS 
Transport Layer Security 
A protocol that ensures secure data transmission between client/server applications communicating via the Internet. It is designed to prevent eavesdropping, tampering, or forgery. TLS consists of two protocols: the TLS Record Protocol uses a data encryption method to ensure that the connection is secure; the TLS Handshake Protocol allows the client and server to authenticate each other and negotiate which encryption method is to be used before exchanging data.