American Express, Microsoft Sign Deal

American Express on Thursday endorsed the technical idea developed by rivals MasterCard and Visa for making credit card transactions more secure over the Internet and other public data networks.

American Express will use the technology through a licensing agreement with Microsoft Corp., which helped develop the specification for authenticating and securing credit card numbers as they move through a data network.

The endorsement gives a boost to attempts to set a standard for online security, but the companies still have to convince wary consumers that they can send their credit card number through computer networks without hackers copying it along the way.

MasterCard and Visa had originally developed separate ideas for solving the data security problem but began working together last summer.

They reached an agreement four weeks ago and published the technical specifications early last week.

American Express made its arrangement with Microsoft after reviewing the specifications, said David Bauman, vice president and general manager of interactive services.