Patent ID: 7447662

Claim:
A method of operating a transaction processing system enabling users to authorize transactions, said system comprising a transaction processing system having at least a first data communications interface and a second data communications interface, comprising: receiving transaction data from an offering party, relating to a specific transaction to be authorized by a user, and receiving a first transaction reference relating to and uniquely identifying said specific transaction via a first data communication path, at said first data communications interface; generating a second transaction reference which is different from the first transaction reference and which uniquely identifies the transaction within the transaction processing system; sending said second transaction reference to the offering party but not to the user; after receiving said transaction data, conducting communications over a second data communication path, different from said first data communication path, with said user over said second data communications interface; using said second path, conducting a secure access procedure in which authentication data is received and said authentication data is verified; using said second path, receiving said first transaction reference relating to and uniquely identifying said specific transaction from said user, said first transaction reference not being previously transmitted to said user in said second communication path; using said second path, receiving confirmation from said user; and in response to said confirmation, transmitting an authorization signal to authorize said transaction, said authorization signal including said second transaction reference.