1. A method for secure electronic commerce transaction executed by a computer, the method comprises: receiving account information regarding an electronic commerce transaction; generating a transaction authorization request message based on the account information, transaction information, and merchant information; encoding the transaction authorization request message in accordance with an error coding dispersed storage function to produce a plurality of encoded data slices; outputting the plurality of encoded data slices to a plurality of dispersed storage units in accordance with an authorization protocol; receiving at least a threshold number of encoded data response slices from the plurality of dispersed storage units in accordance with the authorization protocol; and decoding the plurality of encoded data response slices in accordance with the error coding dispersed storage function to produce a response message.