Transport Layer Security Jobs

Transport Layer Security and its predecessor, Secure Sockets Layer, are cryptographic protocols that provide communication security over the Internet. They use asymmetric cryptography for authentification of key exchange, symmetric encryption for confidentiality, and message authentication codes for message integrity. Several versions of the protocols are in widespread use in applications such as web browsing, electronic mail, Internet faxing, instant messaging, and voice-over-IP. In the TCP/IP model view, TLS and SSL encrypt the data of network connections at a lower sublayer of its application layer. In OSI model equivalences, TLS/SSL is initialized at layer 5 then works at layer 6: first the session layer has a handshake using an asymmetric cipher in order to establish cipher settings and a shared key for that session; then the presentation layer encrypts the rest of the communication using a symmetric cipher and that session key. In both models, TLS and SSL work on behalf of the underlying transport layer, whose segments carry encrypted data. TLS is an IETF standards track protocol, first defined in 1999 and last updated in RFC 5246 and RFC 6176. It is based on the earlier SSL specifications developed by Netscape Communications for adding the HTTPS protocol to their Navigator web browser.