A client-side on-board computing device is partitioned into a trusted computing module, and a private computing platform. When a metric report is required, the private computing platform retrieves an original data file and transfers the original data file to the trusted computing module. The original data file includes a global positioning system coordinate stream and time information. Communication between the private computing platform and the trusted computing module is via an unencrypted serial link. The private computing platform applies at least one billing algorithm to the original data file to determine a billing charge. The private computer platform signs and hashes the billing charge using a private key of a public-private endorsement key pair to create a signed metric report. The private computer platform forwards the signed metric report to the trusted computing module via the unencrypted serial link. The trusted computing module then forwards the signed metric report by the trusted computing module to a billing authority.