Location stamps for digital signatures: A new service for mobile telephone networks

Abstract

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.