Location Stamps for Digital Signatures: A New Service for Mobile Telephone Networks

Location aware services are expected to make up a large share of the mobile telephone market in the future. The services proposed so far make use of uncertified location information--information push services, guidance systems, positioning for emergency calls, etc. We propose a service that provides certified location information. Integrated with cryptographic digital signatures this service enables the determination of the current position of the signer in a provable way. Such certified location information--called location stamp--can be applied in electronic commerce, e.g. for determination of applicable laws or taxes.