The invention provides a method and system for accomplishing two-factor authentication for internet transactions, wherein the user of the device through which the transaction is negotiated needs to give only a single yes/no verification to the system. In some embodiments, the second factor authentication is automated without any action on the part of the user. The method calls on the user's wireless voice device for the detection of environmental wireless signals (“Short Distance Wireless Information” or “SDWI”), and uses these signals collectively as a “fingerprint” that uniquely identifies the wireless signals near the wireless voice device. The system stores these SDWI fingerprints, and later uses the stored information to establish whether or not the user's wireless voice device is near a previously-recognized SDWI.