public key certificate on TLS/SSL Currently I am working on a public key certificate. I got a question: Why is a public key certificate needed for TLS/SSL? Wouldn't TLS/SSL itself is enough? What is the role of the certificate?
The certificate makes sure that whoever you're talking to is who they claim they are. With TLS/SSL without certs you wouldn't notice if you're communicating with an impostor over an encrypted channel instead of whoever you're expecting to communicate with. This leads to so called man-in-the-middle attacks. You really should read this, if you're going to use TLS:

http://en.wikipedia.org/wiki/Certificate_authority