Offline time-stamping using TPM and its Java library

Digital time-stamp is a component for making a digital evidence of data. It proves that there has been a data since a particular time, and the data has not been falsified after time-stamping. A PKI-based time-stamping scheme is standardized in RFC3161. In the scheme, Time Stamping Authority (TSA), which is a trusted third party, issues a digital time-stamp and a client cannot requests time-stamp to TSA without internet access. This paper proposes an offline time-stamping scheme using TPM. TPM is a security chip equipped with a terminal and provides an extra layer of security to the terminal. The proposed scheme can make time-stamp that is detectable with falsification and forgery. The implementation of the proposed scheme requires the knowledge of TPM. This paper shows the Java library for easy development of the offline time-stamping using TPM.