Transport Layer Security (TLS) is a successor of Secure Sockets Layer (SSL) and its a cryptographic protocol used for establishing an encrypted link between a Server and a Client over a public network. They use X.509 certificates and hence asymmetric cryptography to authenticate the certificate holder to its clients, and to negotiate a symmetric session key. This session key is used to encrypt the data communication between client and server. This allows message confidentiality and authenticity. TLS is widely used in applications like:- i. Email ii. Web Broswing iii. VoIP Because of the use of X.509 certificates, CAs and PKI infrastructure are necessary to verify the certificates and for the establishment of chain-of trust. TLS is an Internet Engineering Task Force (IETF) standards track protocol, first defined in 1999 and updated in RFC 5246 (August 2008) and RFC 6176 (March 2011). It is based on the earlier SSL specifications (1994, 1995, 1996) developed by Netscap