Secure electronic transaction Definition
Secure electronic transaction (SET) is a standard protocol for securing credit card transactions over insecure networks, specifically, the Internet. SET was developed by VISA and MasterCard (involving other companies such as GTE, IBM, Microsoft and Netscape) starting in 1996.
SET makes use of cryptographic techniques such as digital certificates and public key cryptography to allow parties to identify themselves to each other and exchange information securely.
SET was heavily publicised in the late 1990's as the credit card approved standard, but failed to win market share. Reasons for this include; need to install client software (an eWallet), cost and complexity for merchants to offer support and comparatively low cost and simplicity of the existing, adequate SSL based alternative.