Explain dissimilar security protocols used for e-commerce applications.  

The e-commerce systems of today are composed of a number of components including: a commerce server, data transaction protocols, and client software from which transactions originate. 

The protocols for e-commerce transactions are: SSL, PCT, SET, S-HTTP, S/MIME, Cybercash, and Digicash between others. Most of these protocols are not interoperable, and consumers must choose one protocol over another. If a merchant is not a subscriber to Cybercash, then a Cybercash consumer will not be capable to purchase wares from the merchant. A consumer does not have a browser client that supports S-HTTP, then the consumer will not be capable to engage in a secure transaction with a merchant that uses S-HTTP. The market may ultimately decide the winners and losers in standardized protocols; though, the necessity for interoperable, cross-platform components will not lessen. Development of secure components for use in building commerce applications is a significant step in the maturation and acceptance process.