Secure electronic transactions (SET):

A protocol standard that ensures the security of financial transactions on the Internet. Developed by credit card companies and various technology companies, SET provides secure transmission of payment information over the Internet and other electronic networks through the use of digital certificates. With SET, a transaction is conducted and verified using a combination of digital certificates and digital signatures among the purchaser, a merchant, and the purchaser's bank. SET uses Secure Sockets Layer (SSL), Secure Transaction Technology (STT), and Secure Hypertext Transfer Protocol (SHTTP).