Secure electronic transaction

Secure Electronic Transaction (SET) was a standard for securing credit card transactions over insecure networks, specifically, the Internet. SET was not itself a payment system, but rather a set of security protocols and formats that enabled users to employ the existing credit card payment infrastructure on an open network in a secure fashion. However, it failed to gain attraction in the market. VISA now promotes the 3-D Secure scheme.

SET was developed by the SET Consortium, established in 1996 by VISA and MasterCard in cooperation with GTE, IBM, Microsoft, Netscape, SAIC, Terisa Systems, RSA, and VeriSign. The consortium’s goal was to combine the card associations' similar but incompatible protocols (STT from Visa/Microsoft and SEPP from MasterCard/IBM) into a single standard.

SET allowed parties to identify themselves to each other and exchange information securely. Binding of identities was based on X.509 certificates with several extensions. SET used a cryptographic blinding algorithm that, in effect, would have let merchants substitute a certificate for a user's credit-card number. If SET were used, the merchant itself would never have had to know the credit-card numbers being sent from the buyer, which would have provided verified good payment but protected customers and credit companies from fraud.

SET was intended to become the de facto standard payment method on the Internet between the merchants, the buyers, and the credit-card companies.

To meet the business requirements, SET incorporates the following features:

A SET system includes the following participants:

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