Really just the level of "trust" and the financial guarantee behind it.
You can do a self signed cert, which will give you the encryption, but nobody will know about it and will be prompted with "unable to be verified" so it is really only any use if the person connecting knows you you and trusts you already.
Also there are certs for different functions and requirements.
To get a recognised cert for financial transactions, you really need a known player.
Verisign is prob the best known root provider, but is $$.
I have used Thawte, and more recently Comodo.
Saying that, there are companies which will do all the payment processing work for you...
Bookmarks